WO2024069001A1 - Method for displaying a luminous animation on a light-emitting system of a motor vehicle - Google Patents

Abstract

The invention relates to a method for displaying a luminous animation on a light-emitting system (1) implemented by a graphics engine (MG1, MG2, MG3) equipped with a library (D2i,j) describing luminous sub-animations, the method comprising the following steps: (E1) providing the graphics engine with a description (D1) of at least one element (21, 22, 12) of the light-emitting system; (E0) receiving a command (Zi) to display a luminous animation (Ai) on the element; (E2) retrieving, on receipt of said command, a set (D2i,j) describing luminous sub-animations forming said luminous animation; (E3, E4, E5, E6, E7) determining, by means of the graphics engine, a sequence of control instructions (bk) for controlling said element on the basis of the description of each luminous sub-animation of said element; (E9) controlling the element by means of the sequence of control instructions so as to display said luminous animation.

Description

Method for displaying a light animation on a lighting system of a motor vehicle

Domain t technical.

The invention relates to the technical field of automobile lighting and/or automobile signaling. More particularly, the invention relates to the field of displaying a light animation on a lighting system of a motor vehicle.

State of technology.

In the field of lighting the interior of motor vehicles or the signaling of motor vehicles, lighting systems now include sufficient light sources so that light animations can be displayed. It is thus known, for example, to display on a rear light of a motor vehicle a light animation consisting of a movement of an arrow making it possible to indicate to a road user a direction that the vehicle will take or even to display on a light strip inside a vehicle a scrolling light signal to indicate to the driver the direction of a danger on the road.

In this type of system, each light animation is determined beforehand based on the number and position of each of the light sources in the light system; the light animation is stored in a memory of the light system in the form of a sequence of instructions for controlling each of these sources. When launching a light animation, a control system is responsible for determining a sequence of instructions for controlling the light sources making it possible to display the light animation on the lighting system of the motor vehicle.

In other words, this type of system is particularly rigid and does not allow animations to be dynamically generated. In addition, for any new animation that we wish to generate, it is necessary to first calculate, on a computer, an entire sequence of control instructions, then store it in the device's memory in order to test it and check it, and modify it if necessary until arriving at a sequence of instructions considered satisfactory. It is therefore not possible to test, generate and update animations simply and quickly. Finally, each animation is particularly dependent on the structure of the light system, and in particular the technologies used and the spatial distribution of the light sources. Any change in the design of a lighting system therefore involves a recalculation of the animations and it is not easy to reuse a previously generated animation for a lighting system.

In this context, a method has been imagined in application FR3096435 in which a simple description of a light animation is provided to a graphics engine, which then determines, for a given structure of a light system, a rendering of this animation light and in which a control of the light system can then control the sources of the light system from this rendering.

The graphics engine can be embedded in a vehicle computer and in a computer equipped with a vehicle simulation environment, it is thus possible to implement a light animation in a virtual representation of the light device without having to physically implement it in the light device itself. From then on, the animation can be tested and validated easily and simply, whatever the design of the light device for which it is intended. Subsequently, only the description of the animation must be provided to the on-board graphics engine so that it can generate a rendering for the design of the vehicle's lighting system. Therefore, this description can be used for different designs and can be easily updated.

While this solution does indeed meet the various needs mentioned above, it has a major drawback. Indeed, in the case of displaying a complex animation requiring several objects or in the case of displaying several simultaneous animations, the size of the RAM and/or the buffer memory required by the graphics engine may be particularly important. Indeed, in the automotive sector, it is not possible to dynamically allocate memory space to a computer. Exceeding this memory space could compromise essential or vital functions of the vehicle, and would therefore pose a major risk to the safety of the vehicle's occupants. In this context, it is therefore necessary to dimension the size of the memory accessible by the graphics engine with respect to the most complex cases, which therefore generates space and cost problems.

There is thus a need for a method for displaying a light animation on a lighting system of a motor vehicle, which makes it possible to easily and simply test, validate and update a light animation whatever the design of the system. light for which it is intended and which does not require significant dimensioning of a RAM and/or a buffer memory for the calculation of the control instructions of the light system.

The invention is therefore placed in this context and seeks to resolve all of the aforementioned drawbacks.

Presentation of the invention.

1. étape de fourniture au moteur graphique d’une description d’au moins un élément du système lumineux définissant le nombre et la position des sources lumineuses de cet élément ;
2. étape de réception par le moteur graphique d’une commande d’affichage d’une première animation lumineuse sur l’élément du système lumineux ;
3. étape de récupération par le moteur graphique, à la réception de ladite commande d’affichage, d’un premier ensemble de description de sous-animations lumineuses stocké dans ladite mémoire et permettant de réaliser ensemble ladite première animation lumineuse ;
4. étape de détermination par le moteur graphique d’une séquence d’instructions de contrôle des sources lumineuses dudit élément pour afficher ladite première animation lumineuse, la séquence d’instructions de contrôle étant déterminée à partir de la description de chaque sous-animation lumineuse du premier ensemble, et en fonction de la description dudit élément ;
5. étape de contrôle par ledit contrôleur, des sources lumineuses de l’élément du système lumineux au moyen de la séquence d’instructions de contrôle pour afficher ladite première animation lumineuse sur le système lumineux.

The subject of the invention is thus a method of displaying a light animation on a lighting system of a motor vehicle comprising a controller and a plurality of light sources selectively controllable by the controller, the method being implemented by a motor graphic equipped with a memory in which a library for describing light sub-animations is stored, comprising the following steps:

1. step of providing the graphics engine with a description of at least one element of the light system defining the number and position of the light sources of this element;
2. step of receiving by the graphics engine a command to display a first light animation on the element of the light system;
3. step of recovery by the graphics engine, upon receipt of said display command, of a first set of descriptions of light sub-animations stored in said memory and making it possible to produce together said first light animation;
4. step of determining by the graphics engine a sequence of instructions for controlling the light sources of said element to display said first light animation, the sequence of control instructions being determined from the description of each light sub-animation of the first together, and depending on the description of said element;
5. step of controlling by said controller, the light sources of the element of the light system by means of the sequence of control instructions to display said first light animation on the light system.

In the invention, the step of providing a description of an element of the light system to the graphics engine makes it possible to know the exact location of the available light sources, in particular their spatial distribution, and to associate each of them with -they have an identifier, in particular a digital index allowing said light source to be individually controlled.

We also understand that the graphics engine is equipped with a library of light sub-animations that can be combined together to form a large number of complex light animations. The graphics engine can thus receive a display command specifying one or more light sub-animations to be produced in order to display a light animation on an element of the light system.

Thus, following receipt of this command to display a first light animation, the graphics engine can thus recover a first set of one or more descriptions of light sub-animations making it possible to generate this first light animation. This decomposition thus makes it possible to limit the working memory space of the graphics engine. Furthermore, the step of determining the instruction sequence by the graphics engine is thus limited to the rendering of these light sub-animations, and therefore of the first light animation, for the available light sources, and not to the entirety of these sub-animations. The graphics engine can then transmit said sequence of instructions to the controller to individually control each of the light sources and assign it the photometric characteristics necessary to correctly render said light animation. We therefore understand that the advantages of the solution of the previous application FR3096435 are thus preserved, each light sub-animation being able to be tested, validated and updated easily, without depending on the design or technology choice of a lighting system, and that the invention also makes it possible to avoid excessive sizing of the RAM and/or the buffer memory of the graphics engine.

In an alternative or cumulative embodiment of the invention, the lighting system could be a virtual lighting system, in particular generated via a computer simulation environment of a motor vehicle and in particular of a passenger compartment of a motor vehicle. Advantageously, the method of displaying a light animation makes it possible to simulate the final rendering of a light animation on such a virtual light system so that the result can be tested and validated prior to its deployment on the real light system of a motor vehicle.

In an alternative or cumulative embodiment of the invention, the lighting system could be a lighting system of a motor vehicle, and in particular a lighting system arranged inside a passenger compartment of a motor vehicle and /or outside a motor vehicle.

Definitions

In the present invention, the term "graphics engine" means one or more electronic components capable of manipulating digital data, in particular an electronic control unit, a central processing unit or a processor which can be embedded in a desktop or laptop computer, a digital tablet or in a motor vehicle, and capable of communicating with memory storage systems and/or electronic systems, in particular through cables or a wireless link, such as the headlights of a motor vehicle.

In the case where the graphics engine is embedded in a motor vehicle, a single graphics engine can be provided for the entire light system or a plurality of graphics engines each associated with a group of light sources of the light system and thus implementing implements the process steps for this group of light sources. If necessary, the lighting system may include a central controller capable of controlling each of these graphics engines.

In the present invention, the term "light source" means any light source, possibly associated with an electro-optical element, capable of being activated, deactivated and/or selectively controlled to emit an elementary light beam whose light intensity is controllable. It may in particular be a light-emitting semiconductor chip, a light-emitting element of a monolithic pixelated light-emitting diode, a portion of a light converter element excitable by a light source or even a light source associated with a liquid crystal or a micro-mirror.

In the present invention, the term “display of a light animation on a light system” means an evolution of the state of at least one light source of this light device over a given time range. Said state may in particular be characterized by a set of photometric characteristics of the light emitted by said at least one light source, in particular the color, the emission intensity, the emission frequency or even the polarization of said emitted light.

The display of a light animation may for example include a modification of the color and/or intensity of the light emitted by all or part of the light sources of the light system and/or the emission of light, momentary and/or or repeated, by all or part of the light sources of the light system to materialize the display and possibly the transformation of one or more objects, for example of their shape, their position, their color and/or their opacity, on all or part of the lighting system and/or to cause a change in a lighting atmosphere, for example its color and/or its intensity, generated by the lighting system. According to the invention, a light animation can be displayed only on only part of the light sources of the light system or on all of them and/or distinct light animations can be displayed on the same set of light sources or on different parts of the sources. lights of the lighting system.

In the present invention, the term “element of the light system” means a predetermined set of light sources. Said element of the lighting system could in particular be a flat and/or curved screen or a strip of light sources or an exterior signaling device, of any shape and dimensions. The light sources of said element may be distributed in a one-dimensional manner, in particular aligned along a line, a curve and/or an arc parameterized in space; or in a two-dimensional manner or even in a three-dimensional manner.

For example, an element of the light system may refer to the total set of light sources of the light system or only to a sub-part of said light sources. For example again, two distinct elements of the lighting system may include one or more common light sources.

1. une consigne d’intensité lumineuse de la source lumineuse,
2. une consigne de couleur de la source lumineuse ou niveau de gris, notamment sous la forme d’un code de couleur du type RVB (Rouge, Vert, Bleu) ou TSV (Teinte, Saturation, Valeur) ;
3. une plage temporelle d’allumage de la source lumineuse.

In the present invention, the term "sequence of instructions for controlling light sources of an element" means a temporal sequence of control instructions, each control instruction comprising a set of information, in particular in the form of a sequence of bits, comprising for each light source of said element at least one elementary instruction among:

1. a light intensity setpoint for the light source,
2. a color instruction of the light source or gray level, in particular in the form of a color code of the RGB (Red, Green, Blue) or TSV (Hue, Saturation, Value) type;
3. a time range for switching on the light source.

If desired, each of said pieces of information can be associated with an identifier of the light source for which it is intended, such as a set of spatial coordinates and/or an index of a pixel. Alternatively, said information may be stored in a table whose order of boxes corresponds to the spatial arrangement of the light sources of said element.

Embodiments

In one embodiment of the invention, the description of said element comprises a description of a model of said element comprising a spatial distribution of light sources of said element and a description of an arrangement of said model in a spatial reference frame.

Advantageously, the spatial reference frame makes it possible to identify by means of coordinates the location of each light source of said element by matching said coordinates of a point of the model to those of the corresponding light source. Said spatial frame of reference may in particular be a two-dimensional or three-dimensional reference frame, not necessarily Euclidean, and may in particular use curvilinear coordinates to locate a point on a curved surface or along a one-dimensional curve in space.

We understand that the description of the model makes it possible to describe the distribution of light sources independently of a spatial reference, so that the same description of a model can be used in the case where two elements of the light system are structurally identical but are positioned at different locations in the motor vehicle, which further limits the memory space required for rendering by the graphics engine. This is particularly the case if the dashboard of the motor vehicle has two identical right and left screens or if the passenger compartment of the vehicle has two light strips arranged symmetrically on the doors.

For example, in the case of a one-dimensional distribution, such as a strip, a spatial distribution of light sources of said element may include only a number of light sources and a step separating two adjacent light sources. Alternatively, in the case of a two-dimensional distribution, such as a screen, a spatial distribution of light sources of said element may only comprise a number of light sources per column and per line and a vertical and/or horizontal step separating two adjacent light sources of the same column and/or the same row. As a further variant, a spatial distribution of light sources of said element may include, may include, for each light source, its position with respect to an original light source.

Preferably, the arrangement of the model may include information making it possible to describe the position of the element in the spatial reference frame and possibly information making it possible to describe an enlargement or reduction factor of the model and/or an angle of rotation of said model.

Advantageously, a library of model descriptions and layout descriptions is stored in the memory and accessible by the graphics engine from said memory. If necessary, the graphics engine selects beforehand from said memory the descriptions of models and arrangements making it possible to describe the different elements of the light system based on identifiers of these descriptions stored in said memory. Alternatively, the identifiers of said descriptions may be selected beforehand and manually by a user.

Advantageously, each description of a light sub-animation stored in said memory of the graphics engine is independent of the number of light sources of the element of the light system and the position of these light sources.

Advantageously still, each description of a light sub-animation can include at least one object and a transformation of said object during a period of time of said object. Preferably, the description of each sub-animation may include a description of an object comprising at least its shape and its position in a spatial frame of reference, in particular the same spatial frame of reference as that of the description of said element, and a description of a transformation of at least one characteristic of said object comprising at least start and end values of said characteristic and a duration of said transformation. For example, objects are described by a set of geometric shapes, for example straight segments or polygons, defined by their vertices. Each control instruction can thus be determined by evaluating a view, also called "frame", of the sub-animation, that is to say of the object at a given moment of the transformation it undergoes. This view being a vector representation of the sub-animation, it is not limited to a given resolution, unlike a matrix representation, so that it is therefore independent of the structure and the choice of technology of the element of the lighting system. Each successive evaluation of a view of the sub-animation, as the transformation undergone by the object evolves from its starting value to its end value and during said duration of the transformation, thus makes it possible to obtain a new instruction for controlling the light sources of the light element and thus to sequentially display the sub-animation on this light element.

If desired, we could provide that each description of a sub-animation includes a single description of an object and at least one description of a transformation of a characteristic of said object.

In the case where said first set comprises at least two descriptions of light sub-animations to be displayed, simultaneously and/or sequentially, on the element of the light system to form the first light animation, it can be provided that each description is associated with at least one priority index and/or at least one opacity coefficient. If necessary, the sequence of control instructions may be determined by the graphics engine from the description, the priority index and/or the opacity coefficient of each light sub-animation, and depending on the description of said element. Indeed, it is for example possible to combine these sub-animations to give a superposition effect to the first animation. For example, the value of the priority index makes it possible to establish an order according to which the different objects of the same animation must be displayed, in particular to produce visual effects of variable depth. Each higher order sub-animation is thus assigned at least one opacity coefficient making it possible to determine whether the lower order sub-animations can show through this higher order sub-animation.

In one embodiment of the invention, all of the descriptions of the light sub-animations are stored in said memory of the graphics engine in the form of a data tree, said data tree comprises a first sub-tree encoding a plurality of object descriptions each comprising one or more characteristics of said object, and a second subtree encoding a plurality of descriptions of a transformation of at least one characteristic of an object. If necessary, the step of recovery by the graphics engine of said first set includes the recovery, for each sub-animation of the first set, of a description of an object in the first sub-tree and of a description of a transformation of at least one characteristic of said object in the second subtree.

In other words, the data tree structure makes it possible to describe in a simple, exhaustive and compact manner all of the information necessary for the construction of the set of descriptions of light sub-animations. By proceeding in this way, each sub-animation is described in full using the object(s) constituting said sub-animation and their respective graphic characteristics, in particular the size and color of said objects, and all the transformations applying to at least one of the graphic characteristics of one of said objects.

If desired, the step of recovering the descriptions of an object and a transformation could be preceded by a step of decompressing the data tree.

1. nombre de sommets dudit objet ;
2. position des sommets dudit objet.

In one embodiment of the invention, for each description of an object stored in said first subtree, said description includes a value of at least one characteristic of the object chosen from at least the following characteristics:

1. number of vertices of said object;
2. position of the vertices of said object.

1. couleur globale de l’objet ;
2. couleur de chacun des sommets de l’objet ;
3. coefficient d’opacité global de l’objet ;
4. coefficient d’opacité de chacun des sommets de l’objet ;
5. indice de priorité.

We could possibly envisage that said description also includes at least one property type characteristic, the value of which can be fixed or modified using a sub-animation, chosen from the following characteristics:

1. overall color of the object;
2. color of each of the vertices of the object;
3. global opacity coefficient of the object;
4. opacity coefficient of each of the vertices of the object;
5. priority index.

In one embodiment of the invention, for each description of a transformation of at least one characteristic of an object stored in said second subtree, said description comprises at least one starting value of said characteristic, a value end of said characteristic, a duration of said transformation and a transition profile of said characteristic from its starting value to its end value. Said transformation could thus indifferently be a transition such as movement of the object to another position, rotation, change of color, change of opacity, modification of the number and/or position of one or more, or even all, of the objects. vertices, or a combination of one or more of these transitions. Where applicable, the transition profile may be a continuous or discontinuous function, such as for example a linear or quadratic or inverse function or even an identity function.

Note that we can thus associate with all the vertices a global, or unique, color of the object or associate a color with each vertex, the set of colors then forming a color map of the object allowing , by interpolation, to define color variations of the object. Equivalent to the color, we can associate with all the vertices a global, or unique, opacity coefficient of the object or associate with each vertex an opacity coefficient, all of the coefficients then forming a map opacity of the object allowing, by interpolation, to define variations in opacity of the object.

By proceeding in this way, it is possible to specify for a given object the temporal and spatial evolution of at least one characteristic; the data tree thus contains all the information necessary for the execution of a light animation, including in the case where several objects are present

1. à partir de ladite description dudit élément, la position de ladite source lumineuse dans ledit référentiel spatial ;
2. pour chaque sous-animation lumineuse du premier ensemble, une valeur de ladite sous-animation lumineuse au niveau de ladite position déterminée et à un instant donné ;
3. une valeur de la première animation lumineuse au niveau de ladite position déterminée à partir de la valeur déterminée de chaque sous-animation lumineuse du premier ensemble ; ladite instruction étant déterminée à partir de ladite valeur déterminée de la première animation lumineuse.

In one embodiment of the invention, the descriptions of the sub-animations stored in the memory are defined in the same spatial reference frame; each instruction of said sequence of control instructions is determined sequentially from the receipt of said command, for each instruction of said sequence of instructions and for each light source of the element of the light system, the graphics engine determines:

1. from said description of said element, the position of said light source in said spatial reference frame;
2. for each light sub-animation of the first set, a value of said light sub-animation at said determined position and at a given time;
3. a value of the first light animation at said position determined from the determined value of each light sub-animation of the first set; said instruction being determined from said determined value of the first light animation.

In other words, for the calculation of an instruction, the graphics engine carries out a sampling of a view at a given moment of each sub-animation with regard to the position of the light sources in the spatial reference frame, it being understood that only the pixel values of each sub-animation corresponding to the positions of the sources are determined. These values could be grayscale values or color values. The views being determined in the same spatial frame of reference, and in particular the same spatial frame of reference as that of the description of said element, the graphics engine can then carry out a coherent superposition of the sub-animations in order to determine the final rendering of the animation in front of it. be displayed on the element of the light system, and therefore determine an instruction. These different steps are thus renewed periodically, each sub-animation being re-evaluated and sampled at a later time to obtain a new instruction from the sequence of instructions until reaching the end of the light animation. We could imagine that the graphics engine determines each value of each light sub-animation through the same execution thread (or in English “thread”) executed by a processor, or through several parallel execution threads, for example executed by a multi-core processor. If necessary, for each light source of the element of the light system, the graphics engine could for example determine all the values of the light sub-animations at the determined position of this light source in the same execution thread associated with this light source, or in an execution thread associated with a set of light sources comprising this light source.

Note that in the case where two sub-animations overlap at the same pixel, the graphics engine can advantageously use the priority indices of the sub-animations and the opacity coefficients to determine the rendering of the animation at the level of this pixel. For example, said value of the light animation could be determined from the determined value of each light sub-animation and weighted using the priority index and/or the opacity coefficient of this sub-animation bright.

It should be noted that the instruction can be formed by all the values of the light animation determined for each of the light sources of the element of the light system, each value then forming an elementary instruction of a light source. Alternatively, these values can be transformed by the graphics engine, for example by means of gamma correction type operations, in order to obtain elementary instructions from the light sources.

1. ultérieurement à la réception de la commande d’affichage de la première animation lumineuse, la réception par le moteur graphique d’une commande d’affichage d’une deuxième animation lumineuse ;
2. à la réception de ladite commande d’affichage de la deuxième animation lumineuse ; la récupération par le moteur graphique dans ladite mémoire d’un deuxième ensemble de description de sous-animations lumineuses permettant de réaliser ensemble ladite deuxième animation lumineuse ;
3. la détermination par le moteur graphique d’une séquence d’instructions de contrôle des sources lumineuses dudit élément pour afficher ladite première animation lumineuse et ladite deuxième animation lumineuse, la séquence d’instructions de contrôle étant déterminée à partir de la description de chaque sous-animation lumineuse du premier ensemble, de la description de chaque sous-animation lumineuse du deuxième ensemble, et en fonction de la description dudit élément.

In one embodiment of the invention, cumulative or alternative, the method comprises:

1. subsequently upon receipt of the command to display the first light animation, reception by the graphics engine of a command to display a second light animation;
2. upon receipt of said command to display the second light animation; the recovery by the graphics engine in said memory of a second set of descriptions of light sub-animations making it possible to produce said second light animation together;
3. determining by the graphics engine a sequence of instructions for controlling the light sources of said element to display said first light animation and said second light animation, the sequence of control instructions being determined from the description of each sub- light animation of the first set, of the description of each light sub-animation of the second set, and according to the description of said element.

By doing so, the graphics engine is capable of generating coherent light source control instructions for any number of animations, including for two light animations offset in time and/or having distinct execution times, due to receiving separate display commands. Indeed, it may be necessary to start, at any time, the display of a second light animation simultaneously with the first light animation currently being displayed. Such a situation arises, for example, during the sudden appearance of a road hazard or a technical fault. In this case, it may be necessary to display a light animation informing a vehicle occupant of the danger and/or technical fault. This light animation can then be superimposed on a first light animation being executed, in particular by being displayed as a priority in relation to said first animation. Note that in this case, the graphics engine renders the light animations in the same spatial reference frame but in distinct temporal frames specific to each light animation.

Similar to sub-animations, it is possible to combine light animations with an overlay or depth effect, by associating a priority index and a depth coefficient with each animation.

1. à partir de ladite description dudit élément, la position de ladite source lumineuse dans ledit référentiel spatial,
2. pour chaque sous-animation lumineuse du premier ensemble et du deuxième ensemble, une valeur de ladite sous-animation lumineuse au niveau de ladite position déterminée ;
3. une valeur de la première animation lumineuse au niveau de ladite position déterminée à partir de la valeur déterminée de chaque sous-animation lumineuse du premier ensemble et une valeur de la deuxième animation lumineuse au niveau de ladite position déterminée à partir de la valeur déterminée de chaque sous-animation lumineuse du deuxième ensemble ; ladite instruction étant déterminée à partir desdites valeurs déterminées des première et deuxième animations lumineuses.

In one embodiment of the invention, for each instruction of said sequence of instructions and for each light source of the element of the light system, the graphics engine determines:

1. from said description of said element, the position of said light source in said spatial reference frame,
2. for each light sub-animation of the first set and the second set, a value of said light sub-animation at said determined position;
3. a value of the first light animation at said position determined from the determined value of each light sub-animation of the first set and a value of the second light animation at said position determined from the determined value of each light sub-animation of the second set; said instruction being determined from said determined values of the first and second light animations.

In one embodiment of the invention, for each instruction of said sequence of instructions, the graphics engine increments an advancement time of each light sub-animation of the first and second sets of sub-animations, the step of determination of the value of each light sub-animation of the first and second sub-assemblies at said determined position being carried out according to said advancement time of this sub-animation.

Preferably, the advancement time of a set of sub-animations, or of each sub-animation of a set of sub-animations is initialized following receipt of the command to display the light animation corresponding to this set. Following the increment of the advancement time, for each instruction, the graphics engine then proceeds to sample a view at said advancement time of each sub-animation, determines a rendering of each animation from the samplings sub-animations of the corresponding set, then composes into a global rendering from these renderings. These incrementation, sampling and rendering calculation steps are thus renewed periodically to generate new instructions until the advancement time of a sub-animation exceeds the duration of the transformation(s) of this sub-animation. -animation. Once this duration has been exceeded, this sub-animation is no longer taken into account in the calculation of the renderings by the graphics engine.

It should be noted that according to this characteristic, the temporal evolution of the sub-animations of each light animation is processed independently of the other light animations. From then on, the speed of each sub-animation can be controlled independently of the other sub-animations. If desired, the advancement time of each light sub-animation could be different for each of said sub-animations, in particular be a multiple, integer or not, of a time unit, in particular 1 ms.

In one embodiment of the invention, the method comprises a step of providing the graphics engine with an image or a sequence of images intended to be displayed simultaneously on the light system with said light animation, said image or sequence images being associated with at least one priority index and/or at least one opacity coefficient; and the sequence of instructions for controlling the light sources of said element to display said light animation is determined by the graphics engine from the description, the priority index and/or the opacity coefficient of each light sub-animation , and said image or sequence of images, its priority index and/or its opacity coefficient. It is thus possible, in addition to the dynamic display of light animations on the light system, to simultaneously display images, for example stored in the memory of the graphics engine or in another memory of the motor vehicle.

It can advantageously be provided that the plurality of light sources forms at least two groups of light sources each defining an element of the light system, the light sources being selectively controllable by a controller; and that the light system comprises a plurality of graphics engines each associated with an element of the light system and a master controller capable of controlling each of the graphics engines; the master controller and the graphics engines each having a clock.

1. étape de fourniture à chaque moteur graphique d’une description de l’élément du système lumineux associé, définissant le nombre et la position des sources lumineuses de cet élément ; 
2. étape de fourniture à chaque moteur graphique d’une description d’au moins une sous-animation lumineuse devant être affichée sur l’élément du système lumineux associé, l’ensemble des sous-animations devant former une animation lumineuse ;
3. étape de fourniture, par le contrôleur maitre, d’un signal d’horloge généré par son horloge, à chacun des moteurs graphiques ;
4. étape de calcul, par chaque moteur graphique, d’un décalage temporel entre un signal d’horloge généré par son horloge et le signal d’horloge fourni par le contrôleur maitre ;
5. étape de détermination, par chaque moteur graphique, d’une séquence d’instruction de contrôle des sources lumineuses de l’élément du système lumineux associé, chaque instruction étant déterminée à partir de la description dudit élément associé, de la description de la sous-animation lumineuse fournie à ce moteur graphique et d’un temps d’avancement de ladite sous-animation lumineuse déterminé à partir dudit décalage temporel ;
6. étape de contrôle, par le contrôleur, des sources lumineuses de chaque élément du système lumineux au moyen de la séquence d’instructions de contrôle déterminée par le moteur graphique associé pour afficher ladite sous-animation lumineuse sur cet élément

If applicable, the process then comprises the following steps:

1. step of providing each graphics engine with a description of the element of the associated light system, defining the number and position of the light sources of this element;
2. step of providing each graphics engine with a description of at least one light sub-animation to be displayed on the element of the associated light system, all of the sub-animations having to form a light animation;
3. step of supplying, by the master controller, a clock signal generated by its clock, to each of the graphics engines;
4. step of calculating, by each graphics engine, a time offset between a clock signal generated by its clock and the clock signal supplied by the master controller;
5. step of determining, by each graphics engine, an instruction sequence for controlling the light sources of the element of the associated light system, each instruction being determined from the description of said associated element, from the description of the sub- light animation supplied to this graphics engine and an advancement time of said light sub-animation determined from said time offset;
6. step of controlling, by the controller, the light sources of each element of the light system by means of the sequence of control instructions determined by the associated graphics engine to display said light sub-animation on this element

It is thus understood that each graphics engine implements the same steps of the method according to the invention, as described previously, the instructions being determined according to its own clock frequency, each instruction being for example generated for each period, or multiple of periods, clock. However, it is possible that the clock frequency differs significantly from one graphics engine to another, under the influence of an external parameter such as temperature or even manufacturing tolerances of the graphics engines. These offsets then lead to a desynchronization of the instruction sequences generated by the graphics engines, so that an unpleasant effect may be visible when displaying a light animation on several elements of the same light system. The aforementioned characteristics thus allow each microcontroller to estimate the time offset of its clock with respect to the same reference clock signal, then to generate instructions which compensate for this estimated offset.

1. incrémente le temps d’avancement de la description de la sous-animation lumineuse fournie à ce moteur graphique à l’aide d’un pas temporel déterminé à partir dudit décalage temporel ;
2. détermine, à partir de ladite description dudit élément associé, la position de ladite source lumineuse dans ledit référentiel spatial ;
3. détermine une valeur de ladite sous-animation lumineuse au niveau de ladite position déterminée et audit temps d’avancement de cette sous-animation, ladite instruction étant déterminée à partir de ladite valeur déterminée de cette sous-animation lumineuse

Advantageously, each graphics engine, for each instruction of said sequence of instructions and for each light source of the element of the associated light system:

1. increments the advancement time of the description of the light sub-animation supplied to this graphics engine using a time step determined from said time offset;
2. determines, from said description of said associated element, the position of said light source in said spatial reference frame;
3. determines a value of said light sub-animation at said determined position and said advancement time of this sub-animation, said instruction being determined from said determined value of this light sub-animation

Preferably, the steps of incrementing the advancement time, determining the position of the light source and determining the value of the light sub-animation are renewed until the advancement time exceeds the duration of the transformation of said sub-animation. In other words, the graphics engine can thus adapt the number of views of a sub-animation that it evaluates to render this sub-animation, with regard to the duration specified in the description of this sub-animation . However, each evaluated view can give rise to a new control instruction, so that the number of evaluated views directly impacts the actual display duration of the sub-animation on the element of the light system. It is thus possible to modulate the display duration of each sub-animation so that the sub-animations are displayed synchronously.

Advantageously, the graphics engine increases the time step if the period of the clock signal generated by its clock is greater than the period of the clock signal supplied by the master controller and decreases the time step if the period of the clock signal generated by its clock is less than the period of the clock signal provided by the master controller. In other words, the time step is increased if the graphics engine clock is slower than that of the master controller and it is decreased if the graphics engine clock is faster than that of the master controller.

For example, the graphics engine can change the time step using a factor determined from the ratio between the period of the clock signal provided by the controller and the period of the clock signal generated by its clock.

In one embodiment of the invention, the step of determining by the graphics engine a sequence of instructions for controlling the light sources of said element to display said first light animation comprises the generation of a sequence of instructions for controls each associated with one of the light sources of said element, the ordering of said sequence of instructions corresponding to the arrangement of the light sources of said element with respect to the motor vehicle.

Therefore, said sequence of light source control instructions unequivocally defines sequences of instructions for each of the light sources according to its position in the spatial reference frame. Thus, the image constructed by all the light sources makes it possible to generate a coherent overall image in relation to the light animation resulting from the different light animation display commands received by said graphics engine.

Preferably, when the controller of the light system receives a control instruction determined by the graphics engine, it successively controls the light sources of the element of the light system according to this control instruction. For example, for each control instruction, in the case where each light source of the element of the lighting system comprises three light emitting chips of red, green and blue color respectively, the controller will be able to generate for each selected light source, three signals modulated in PWM (Pulse Width Modulation) whose cyclic ratios are determined according to the instruction contained in the control instruction associated with this light source and supplies these signals to said light source.

The invention also relates to a computer program comprising a program code which is designed to implement the method according to the invention.

The invention also relates to a data carrier on which the computer program according to the invention is recorded.

Brief description of the figures.

The present invention is now described using examples that are purely illustrative and in no way limiting the scope of the invention, and from the attached illustrations, in which:

represents, schematically and partially, a lighting system of a motor vehicle for implementing a method according to one embodiment of the invention;

represents, schematically and partially, a method of displaying a light animation on the light system of the according to one embodiment of the invention;

represents, schematically and partially, a data tree in which is stored a plurality of descriptions of light sub-animations for the implementation of the method of the ;

represents, schematically and partially, an example of implementation of the method of for displaying a light animation on the light system of the ;

represents, schematically and partially, a temporal graph describing a sequence of light animations displayed on the light system of the using the process of ;

represents, schematically and partially, a temporal graph representing a sequence of light animations displayed on the light system of the ; And

represents, schematically and partially, a temporal graph representing a sequence of light animations displayed on the light system of the using the process of .

In the description which follows, identical elements, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references.

Description of the embodiments.

We represented in a lighting system 1 of a motor vehicle for implementing a method of displaying one or more light animations according to one embodiment of the invention.

In the example described, the lighting system 1 is a lighting system for the passenger compartment of the motor vehicle, comprising a central strip 21 of light sources arranged at the level of a dashboard of the vehicle as well as a straight strip 22 and a left strip 23 of light sources arranged symmetrically at the level of the right and left doors of the vehicle. Each of the strips 21, 22 and 23 comprises a matrix of light sources of the light-emitting diode type, distributed in rows and columns. Furthermore, the strips 22 and 23 are symmetrically identical. Each of the strips thus forms an element of the lighting system 1.

This example is given on a non-limiting basis, and other types of lighting systems could be designed without departing from the scope of the present invention. In particular, it will be possible to vary the number of elements of the lighting system, their arrangement with regard to the motor vehicle, whether interior or exterior, the number of light sources for each element, their spatial distribution, their dimensions, the type of light. that they are likely to emit as well as the technology of these light sources without departing from the scope of the present invention. Each element could indifferently be a device of an interior lighting system of the motor vehicle, a road lighting device or a signaling device of the motor vehicle.

Each element 21 to 23 of the light system 1 is associated with a graphics engine MG ₁ to MG ₃ , intended to generate instructions for controlling the light sources of this element, and a controller P ₁ to P ₃ , intended to control the light sources of this element from the instructions generated by the associated graphics engine.

Each graphics engine includes a memory (not shown), in which a library of descriptions of light sub-animations and a library of descriptions of elements of light systems are stored.

The lighting system 1 also includes a BCM master controller capable of controlling each of the graphics engines and transmitting data frames to them, via an on-board data communication network.

We represented in a method of displaying a light animation on the system 1 according to one embodiment of the invention.

It should be noted that the light system 1 can be a real light system of a motor vehicle or a virtual light system, simulated through a simulation environment of the motor vehicle, in order to test and validate light animations before deploy them on a real vehicle. The description of the process which follows can thus be applied equally to a real light system or to a simulated light system.

For the sake of brevity, the process will be described with respect to the graphics engine MG ₁ alone, the controller P ₁ and the element 21, it being understood that the same process is implemented by the other graphics engines, controllers and elements.

In a step E0, the graphics engine MG ₁ receives a display command Zi of a light animation A _i on the element 21.

In a step E1, the graphics engine MG ₁ retrieves, in its memory, a description D1 of the element 21 and in a step E2, the graphics engine MG ₁ retrieves, in its memory, a set of descriptions D2 _{i, j} of light sub-animations allowing the light animation A _i to be created together.

The descriptions D1 of element 21 and D2 _{i, j} of each light sub-animation could for example be retrieved using identifiers of element 21 and the sub-animations contained in the command Z _i . Depending on the command Z _i , the set of sub-animation descriptions may include one or more descriptions D2 _{i, j} .

The library of element descriptions could for example include a sub-library of descriptions of element models, that is to say of different spatial distributions of light sources independent of any spatial reference, and a sub-library descriptions of model layouts, that is to say information allowing a model to be positioned, whatever its type, in a given spatial reference frame.

We thus understand that the combination of a description of an element model and a description of a model arrangement, recovered at the end of step E1, thus allows the graphics engine MG ₁ to know the position of each of the light sources of element 21 in the spatial reference frame of the motor vehicle.

The use of these two libraries allows the same graphics engine to flexibly manage a large number of different types of elements, without increasing the RAM or buffer space it requires. We further note that these libraries are particularly advantageous in the context of elements 22 and 23, which are symmetrical, and can therefore be described by the same model but with different arrangements.

Similarly, the library of light sub-animation descriptions includes a sub-library of object descriptions, in the same spatial frame of reference as that used for the model layout descriptions, and a sub-library of transformation descriptions. of at least one characteristic of an object.

In other words, each description D2 _{i, j} of a light sub-animation retrieved by the graphics engine MG ₁ can be described by a combination of a single description O _J of an object from the sub-library of descriptions object and at least one description T _j of a transformation of a characteristic of this object from the sub-library of transformation descriptions.

Note that, in the example described, an object is described, in its description O _j , by means of the number of its vertices and their positions. Furthermore, each object has properties such as a global color, a global opacity coefficient and a priority index, the values of which are not fixed in the description which is stored and which define modifiable characteristics of the object by a sub-animation. We can replace the global color and/or the global opacity coefficient by a color and/or opacity map defining a color and/or an opacity coefficient for each of the vertices. An object could thus be a geometric shape, a symbol, a pictogram, even an entire background, or even a combination of several of these elements.

Furthermore, a transformation of a characteristic of an object is described, in its description T _j , by a starting value, an arrival value, a transformation duration and a transition profile. A transformation could thus be a change in color, opacity, position or shape of an object.

In other words, it is possible to evaluate a view, or “frame”, of a light sub-animation at a given moment by applying the or each characteristic transformation, defined by the description T _j , to this characteristic of the object, as defined by the description O _j , until this given moment. The value of this characteristic at this given instant can be obtained by interpolation, using the starting and finishing values, the transformation duration, the transition profile and this given instant. The representation of the object being vector, it is not limited to a particular resolution, so that the sub-animation is independent of the choice of structure or technology of the element 21.

The library of descriptions of light sub-animations can be stored in the memory of the graphics engine MG ₁ in the form of a data tree A. As shown in , this data tree includes a first subtree O encoding a plurality of object descriptions O ₁ to O _n ; each of the descriptions comprising several characteristics C ₁ to C _m . The data tree also includes a second subtree T encoding a plurality of descriptions T ₁ to T _p of a transformation of a characteristic of an object. The library of element descriptions can also be stored in the memory of the graphics engine MG ₁ in the form of a data tree.

At the end of steps E1 and E2, once the description D ₁ and all of the descriptions D2 _{i, j} have been retrieved, the graphics engine MG ₁ initializes a progress time t _{i, j} for each of the light sub-animations corresponding.

In a step E3, for each sub-animation, the advancement time t _{i ,j} of this sub-animation is incremented by a time step Δt _i,j , specific to this sub-animation. The steps making it possible to determine this time step Δt _i,j will be described later. This advancement time t _{i, j} is then compared to the duration θ _j of the sub-animation, as defined in the description D2 _{i, j} of this sub-animation.

If the advancement time t _i,j is greater than the duration θ _j of the sub-animation, this sub-animation is then no longer taken into account for the subsequent steps.

Otherwise, in a step E4, the graphics engine MG ₁ estimates the position p _k of each light source of element 21 in the spatial reference frame. It should be noted that, in the case where the element 21 is not affected by the command Z _i , none of the light sources is necessary for the display of the light animation Ai so that the steps E1 to E9 are not implemented.

Note that the positions p _k can be one or more coordinates in the spatial reference frame of description D1, depending on whether the light sources of element 21 are distributed in a one-dimensional, two-dimensional or three-dimensional manner. These coordinates can be determined by positioning the model of element 21, as defined in description D1, in the spatial reference frame defined in the arrangement of the model of description D1, and possibly by applying transformations to this model, such as a rotation, a symmetry and/or a change of scale, if such transformations are defined in the model layout of description D1.

Then, in a step E5, for each description D2 _{i, j} of a light sub-animation and for each position p _k thus determined, the graphics engine MG ₁ determines a value v _{i, j, k} of this light sub-animation at this position p _k and at the advancement time t _i,j . As described previously, the value of each of the characteristics of the object concerned by this sub-animation at this advancement time can be obtained by interpolation, so that a view of the sub-animation at this advancement time can be evaluated and that the color and/or gray level of a portion of the view of this sub-animation, at a given position and for this advancement time, can be determined. However, only the values of the view at the positions p _k are necessary for the display of the light sub-animation on the element 21. The graphics engine MG ₁ thus proceeds to sampling this view using the positions p _k .

In a step E6, for each position p _k , the graphics engine MG ₁ determines a value a _{i, k} of the light animation A _i at this position p _k using all the values v _{i, j,k} light sub-animations determined at the end of step E5.

In this context, as previously explained, each description O _j of an object includes an opacity coefficient α _j , defining the transparency of the object, and a priority index z _j , defining the plane in which the object appears. object. This opacity coefficient α _j and this priority index z _j are thus used in step E6 to be able to compose the sub-animations together according to an alpha composition by superimposing them according to their priority indices sorted in descending order, each sub -animation letting the sub-animations placed below show through more or less depending on its opacity coefficient.

More precisely, each value has_i,k of the light animation A_i at a position p_k can be obtained by summing the values v_i,j,k bright sub-animations, each v value_i,j,k of a light sub-animation being weighted by a coefficient determined from the opacity coefficient α_j and the priority index z_j of this luminous sub-animation.

There represents an example of implementation of steps E4 to E6 for two light sub-animations D2 ₁ and D2 ₂ evaluated at a given time t. As shown, the light sub-animation D2 ₁ has an opacity coefficient α ₁ of 1, meaning that it is completely opaque, while the light sub-animation D2 ₂ has an opacity coefficient α ₂ of 0, meaning that it is completely transparent. Furthermore, the light sub-animation D2 ₁ has a priority index z ₁ of 1 and the light sub-animation D2 ₂ has a priority index z ₂ of 0, meaning that the light sub-animation D2 ₁ is located at the above D2 ₂ .

We will see that, despite the opacity of the sub-animation D2 ₁ , the values of v _{i, 1 , k} which are zero, due to the absence of an object at their position p _k , have been assigned an opacity coefficient of 0 so as to let the values v _{i, 2 , k} of the sub-animation D2 ₂ located below show through.

It should be noted that the steps which have just been described are implemented for the display of a given light animation A _i , following receipt of the instruction Z _i . It is however possible that another light animation, or even several other light animations, is being displayed on element 21. The operations of steps E3 to E6 as previously described can thus be implemented for other light sub-animations described by another set D2 _{i ' , j} of light sub-animations, recovered by the graphics engine MG ₁ following receipt of an instruction Z _I' for the display of another light animation A _{i '} , the implementation of these steps thus allowing the graphics engine to obtain values a _{i ' , k} of the light animation A _{i '} at the positions p _k .

Thus, in a step E7, the graphics engine MG ₁ thus composes all the light animations A _i currently being executed, in a manner similar to step E6, namely by an alpha composition.

For these purposes, the graphics engine MG ₁ assigns to each light animation A _i currently running an opacity coefficient and a priority index. For example, an opacity coefficient and a priority index can be assigned to a light animation A _i , following receipt of the corresponding command Z _i and in particular based on information contained in this command.

The graphics engine MG ₁ can thus determine control instructions b _k for each of the positions p _k , using all the values a _{i, k} of the light animations A _i determined at the end of step E6 . These control instructions b _k are intensity and/or color instructions which are advantageously organized in a table transmitted to the controller P ₁ . It should be noted that the position of a control instruction b _k in the table corresponds to the position p _k of the light source within element 21.

In a step not shown, the graphics engine MG1 can carry out a gamma correction of each of the control instructions b _k .

Steps E3 to E7 are thus renewed sequentially, for each light sub-animation of each light animation Ai, until the advancement time t _i,j of this sub-animation becomes greater than the duration θ _j of this sub-animation. As indicated previously, this sub-animation is then no longer taken into account for the calculation of the following b _k control instructions.

All of these cycles thus make it possible to obtain a sequence of control instructions for the display of the light animations A _i . Once all of the sub-animations of a light animation A _i have been executed, the animation A _i is considered finished and is no longer taken into account for the calculation of the following control instructions b _k .

Each control instruction b _k thus allows the controller P ₁ to control the light source of the element 21 corresponding to the position p _k so that it emits, or not, an elementary light beam whose intensity and/or color depends on this control instruction b _k .

For these purposes, in a step E8, the controller P1 can for example generate, for each light source of the element 21, one or more pulse width modulated signals, or PWM, whose duty cycles τ_k are determined based on the control instruction b_k associated with position p_k of this light source, depending on whether this instruction defines a gray level or a color_.

In a step E9, the light sources of element 21 are controlled by means of PWM signals, so that all of the elementary beams emitted by the light sources of element 21 materialize all of the light sub-animations of the elements. animations Ai, at advancement times t _i,j .

We have thus represented in a temporal graph representing different control instructions b _k generated sequentially by the graphics engines MG ₁ , MG ₂ and MG ₃ for the display of two light animations A ₁ and A ₂ on the elements 21, 22 and 23 of the light system 1.

The light animation A ₁ corresponding to a change in color of an ambient light emitted by the elements 21, 22 and 23, all of the light sources of these elements thus participating in this light animation A ₁ . The light animation A ₂ corresponds to the display of arrows moving from the center of the element 21 towards the end of the element 22, in order to signal to an occupant of the vehicle an event located on the right side of the vehicle . The command Z ₂ , supplied to each graphics engine and causing the display of the animation A ₂ can for example result from the detection, by one or more sensors of the vehicle, of said event.

Each graphics engine MG ₁ , MG ₂ and MG ₃ includes a clock making it possible to sequence the calculation of the control instructions b _k . Each clock thus generates a clock signal having a period Δ _C and each control instruction being generated after the same cycle of periods Δ _C.

In the ideal example of , the periods Δ_vs clocks are identical, so the control instructions b_k are generated by MG graphics engines₁, M.G.₂ and M.G.₃ synchronously.

However, it is common for the clock periods of two graphics engines to differ. In the example shown in , the period Δ_C1 of the MG graphics engine₁ is longer than the period Δ_C2 of the MG graphics engine_2.

As a result, the control instructions b_k are generated by the MG graphics engine₁ slower than those generated by the MG graphics engine_2.It follows that the duration of the light animation A₂ as displayed is shorter for element 22 than for element 21. Therefore, the occupant of the vehicle can observe that the scrolling speed of the arrow of animation A₂ is faster when displayed on element 22 than when displayed on element 21, which can be annoying.

In order to overcome this drawback, in a step E10, the master controller BCM, which is also equipped with a clock, transmits to all the graphics engines MG ₁ , MG ₂ and MG ₃ of the light system 1 a data frame containing its signal clock with its period Δ _c .

In a step E11, each graphics engine compares the period of its clock signal to that of the master controller. In the example of the , the period Δ _C1 of the graphics engine MG ₁ is identical to the period Δ _C of the master controller BCM, while the period Δ _C1 of the graphics engine MG ₂ is shorter.

In step E11, in the event of a variation between these periods, each graphics engine thus calculates the ratio between the period Δ _C of the master controller BCM and its own period and determines a value of the time step Δt _i,j used to increment the time advancement t _{i ,j} from this offset. More precisely, this time step Δt _i,j will be increased if the ratio is less than 1 and will be decreased if the ratio is greater than 1.

In the example of the , the time step Δt ₂ used by the graphics engine MG ₁ is therefore greater than the time step Δt' ₂ used by the graphics engine MG ₂ .

We thus see that the number of cycles of steps E3 to E7 necessary for the advancement time of animation A ₂ to be greater than the duration of this animation is more important for the graphics engine MG ₂ than for the graphics engine MG ₁ . Therefore, the actual display duration of animation A ₂ on element 22 is extended and the effect observed by the occupant in the example of the disappears in the example of the .

The preceding description clearly explains how the invention makes it possible to achieve the objectives it has set for itself, and in particular by proposing a method of displaying a light animation on a light system which makes it possible to test and validate this light animation, independently of the structure, design or technological choices of the light system, and which does not require significant dimensioning of a RAM and/or a buffer memory for the calculation of the control instructions of the light system.

In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically effective combination of these means.

Claims (12)

1. Method for displaying a light animation on a light system (1) of a motor vehicle comprising a controller (P ₁ , P ₂ , P ₃ ) and a plurality of light sources selectively controllable by the controller, the method being implemented implemented by a graphics engine (MG ₁ , MG ₂ , MG ₃ ) equipped with a memory in which a description library (D2 _{i, j} ) of light sub-animations is stored, comprising the following steps:

   1. step (E1) of providing the graphics engine with a description (D1) of at least one element (21, 22, 23) of the light system defining the number and position of the light sources of this element;
   2. step (E0) of reception by the graphics engine of a display command (Z _i ) of a first light animation (A _i ) on the element of the light system;
   3. step (E2) of recovery by the graphics engine, upon receipt of said display command, of a first set of descriptions (D2 _{i, j} ) of light sub-animations stored in said memory and making it possible to produce said first together light animation;
   4. step (E3, E4, E5, E6, E7) of determining by the graphics engine a sequence of control instructions (b _k ) of the light sources of said element to display said first light animation, the sequence of control instructions being determined from the description of each light sub-animation of the first set, and as a function of the description of said element;
   5. step (E9) of controlling, by said controller, the light sources of the element of the lighting system by means of the sequence of control instructions to display said first light animation on the light system.
2. Method according to the preceding claim, in which the description (D1) of said element (21, 22, 23) comprises a description of a model of said element comprising a spatial distribution of light sources of said element and a description of an arrangement of said model in a spatial reference frame.
3. Method according to one of the preceding claims, in which all of the descriptions (D2 _{i, j} ) of the light sub-animations are stored in said memory of the graphics engine (MG ₁ , MG ₂ , MG ₃ ) in the form of a data tree (A), said data tree comprises a first sub-tree (O) encoding a plurality of descriptions (O ₁ , O _n ) of objects each comprising one or more characteristics (C ₁ , C _m ) of said object , and a second subtree encoding a plurality of descriptions (T ₁ , T _p ) of a transformation of at least one characteristic of an object; characterized in that the recovery step (E2) by the graphics engine of said first set comprises the recovery, for each sub-animation of the first set, of a description (O _j ) of an object in the first sub-tree and a description of a transformation (T _j ) of at least one characteristic of said object in the second subtree.
4. Method according to the preceding claim, characterized in that, for each description (O ₁ , O _n ) of an object stored in said first subtree (O), said description includes a value of at least one characteristic (C1, C _m ) of the object chosen from at least the following characteristics:

   1. number of vertices of said object;
   2. position of the vertices of said object.
5. Method according to the preceding claim, characterized in that, for each description of a transformation (T ₁ , T _p ) of at least one characteristic (C1, C _m ) of an object stored in said second subtree (T ), said description comprises at least a starting value of said characteristic, an end value of said characteristic, a duration of said transformation and a transition profile of said characteristic from its starting value to its end value.
6. Method according to one of the preceding claims, in which the descriptions of the sub-animations stored in the memory are defined in the same spatial reference frame, characterized in that each instruction (b _k ) of said sequence of control instructions is determined sequentially from the reception of said command (Z _i ) and in that, for each instruction of said sequence of instructions and for each light source of the element (21, 22, 23) of the light system (1), the graphics engine (MG ₁ , MG ₂ , MG ₃ ) determines:

   1. (E4) from said description (D1) of said element, the position (p _k ) of said light source in said spatial reference frame;
   2. (E5) for each light sub-animation of the first set (D2 _{i, j} ), a value (v _i,j,k ) of said light sub-animation at said determined position and at a given time (t _{i, j} );
   3. (E6) a value (a _i,k ) of the first light animation (A _i ) at said position determined from the determined value of each light sub-animation of the first set; said instruction being determined from said determined value of the first light animation.
7. Method according to one of the preceding claims, the method comprising:

   1. (E0) subsequently upon receipt of the display command (Z _i ) of the first light animation (A _i ), reception by the graphics engine (MG ₁ , MG ₂ , MG ₃ ) of a display command a second light animation;
   2. (E2) upon receipt of said command to display the second light animation; the recovery by the graphics engine in said memory of a second set of descriptions (D2 _{i, j} ) of light sub-animations allowing said second light animation to be produced together;
   3. (E3, E4, E5, E6, E7) the determination by the graphics engine of a sequence of control instructions (b _k ) of the light sources of said element to display said first light animation and said second light animation, the sequence d 'control instructions being determined from the description of each light sub-animation of the first set, from the description of each light sub-animation of the second set, and as a function of the description (D1) of said element (21, 22, 23).
8. Method according to claim 7 in combination with claim 6, characterized in that, for each instruction (b _k ) of said sequence of instructions and for each light source of the element (21, 22, 23) of the light system, the graphics engine (MG ₁ , MG ₂ , MG ₃ ) determines:

   1. (E4) from said description (D1) of said element, the position (p _k ) of said light source in said spatial reference frame,
   2. (E5) for each light sub-animation of the first set (D2 _{i, j} ) and the second set, a value (v _{i, j , k} ) of said light sub-animation at said determined position;
   3. (E6) a value (a _i,k ) of the first light animation at said position determined from the determined value of each light sub-animation of the first set and a value of the second light animation at said position determined from the determined value of each light sub-animation of the second set; said instruction being determined from said determined values of the first and second light animations.
9. Method according to the preceding claim, characterized in that, for each instruction (b _k ) of said sequence of instructions, the graphics engine (MG ₁ , MG ₂ , MG ₃ ) increments an advancement time (t _i,j ) of each light sub-animation of the first (D2 _i,j ) and the second sets of sub-animations, the step (E5) of determining the value (v _i,j,k ) of each light sub-animation of the first and the second sub-assemblies at said determined position (p _k ) being carried out according to said advancement time of this sub-animation.
10. Method according to one of the preceding claims, characterized in that the step of determining (E3, E4, E5, E6, E7) by the graphics engine (MG ₁ , MG ₂ , MG ₃ ) a sequence of instructions control (b _k ) of the light sources of said element (21, 22, 23) to display said first light animation (A _i ) comprises the generation of a sequence of control instructions (b _k ) each associated with one light sources of said element, the ordering of said sequence of instructions corresponding to the arrangement of the light sources of said element with respect to the motor vehicle.
11. Computer program comprising program code which is designed to implement the method according to one of claims 1 to 10.
12. Data carrier on which the computer program according to claim 11 is recorded.