JP5043919B2 - Image generating apparatus, image generating method, and program - Google Patents

Description

  The present invention provides an image generation apparatus, an image generation method, and a computer that are suitable for increasing the number of control points that can be processed in image generation from a three-dimensional model defined by bones and control points. Regarding the program.

  Conventionally, a technique has been proposed in which the shape of a character or the like placed in a virtual space is represented by a three-dimensional model and an image is generated from the three-dimensional model.

  In such technology, bones are connected to define the outline of a character or the like. The bone is equivalent to the character's bone.

  These bones have dependencies. A bone whose position and orientation with respect to the virtual space are defined as a basis, and a bone connected to this underlying bone is defined with a relative position and orientation relative to the foundation bone, and relative to a bone whose position and orientation are determined. By determining the direction and the other bones are connected, the shape of the whole bone is determined by repeating this operation.

  Each bone has a fixed control point. The control point corresponds to a predetermined position on the character's skin and moves in conjunction with the movement of the bone. That is, its position is fixed relative to the bone.

  The shape of the skin is determined by a polygon whose control point is the vertex, a polygon whose vertex is the weighted average position of the control point, or a NURBS (Non Uniform Rational B Spline) surface whose shape is defined by the control point. It is done. The skin corresponds to the surface of the character, that is, the skin.

  When generating an image of a character, etc., from a skin, select polygons in order from the viewpoint (in order of depth), acquire the area where the selected polygons are projected on the projection plane, Drawing is performed by deforming and pasting the texture image. Therefore, it is necessary to sort polygons based on the distance from the viewpoint.

  When the relative position of the bones changes, the control point moves accordingly, the shape of the skin is deformed, and the generated image also changes. By such deformation, it becomes possible to express changes in the position and posture of a three-dimensional model such as a character by animation.

  These three-dimensional graphics processes are often accelerated using an image processing coprocessor or the like.

  In Patent Documents 1, 2, and 3 listed below, techniques for operating each part of a character using bones and control points are proposed.

Japanese Patent No. 4287479 JP 2009-187472 A Japanese Patent No. 4199764

  However, when the performance of the image processing coprocessor, such as a portable information processing apparatus, is low, a large number of bones, control points, polygons, etc. may not be processed at a time.

  Therefore, even when the number of control points that can be processed at one time is limited, there is a strong demand for generating an image using a three-dimensional model exceeding the control points.

  The present invention solves the above-described problems, and is an image generation apparatus and image generation suitable for increasing the number of control points that can be processed in image generation from a three-dimensional model defined by bones and control points. It is an object of the present invention to provide a method and a program for realizing the method on a computer.

  In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

  An image generation apparatus according to a first aspect of the present invention generates an image from a plurality of bones and a plurality of control points arranged in a virtual space.

  Hereinafter, when the position and orientation of a certain bone is determined relative to another bone, the certain bone depends on the other bone.

  Further, when the position and orientation of a certain bone are determined with respect to the virtual space, the certain bone depends on the virtual space.

  On the other hand, the relative position of each of the plurality of control points with respect to any of the plurality of bones is fixed. Therefore, when a certain bone changes its position and orientation in the virtual space, the position and orientation of the control point fixed to the bone also changes accordingly.

  The types of the plurality of bones include a main bone, one of the main bones depends on the virtual space, and each of the other main bones is one of the other main bones. The plurality of control points are classified into groups for the main bone when the bone to which the relative position of the control point is fixed is the main bone.

  That is, in the present invention, it is assumed that all bones are main bones, and control points are classified into groups for any main bone. As will be described later, even in a mode in which a bone has a main bone and a sub-bone, if the control points are classified into groups for any of the main bones, they are included in the scope of the present invention.

  The image generation apparatus of the present invention includes a storage unit, a main update unit, a selection unit, a position calculation unit, a skin calculation unit, a drawing unit, and a display unit, and is configured as follows.

  That is, the storage unit stores the relative position and orientation of each of the plurality of bones with respect to other bones on which the bone depends.

  In addition, the storage unit stores various types of information such as the type of bone, the coordinates of control points fixed to a bone, polygons and NURBS curved surfaces defined by the control points, and texture information to be pasted. Is done.

  On the other hand, the main updating unit updates the position and orientation of each main bone stored in the storage unit based on the passage of time or an instruction from the user.

  For example, when a three-dimensional model defined by bones and control points represents the outer shape of the character, the position and orientation of the character change by updating the position and orientation of the main bone.

  Further, when updated by the main update unit, the selection unit determines the order of the main bones based on the viewpoint position in the virtual space and the respective depths of the main bones with respect to the line-of-sight direction, and in the determined order, Select the main bones in order.

  In normal three-dimensional graphics, the depth from the viewpoint is obtained for all polygons, all the polygons are sorted in order from the viewpoint, and the polygons are drawn in order. On the other hand, in the present invention, the main bones are sorted and, as will be described below, for each main bone, polygons formed by control points classified into groups for the main bone are drawn.

  In this way, the position of the main bone relative to the group to which the control point defining the polygon belongs is not determined by using the position of the polygon itself to determine the context in which the polygons are hidden or hidden from each other. It is one of the features of the present invention to make a judgment using it.

  Further, the position calculation unit calculates the position in the virtual space of the control points classified into the group for the selected main bone.

  When determining the order of the main bones, the position and orientation of each main bone in the virtual space are fixed. Therefore, based on this information, the position of each control point in the virtual space can be calculated.

  Then, when the position of the control point is calculated, the skin calculation unit calculates the shape of the skin from the calculated position of the control point.

  Typically, the shape of the skin is determined by a polygon whose vertex is the control point itself, a polygon whose vertex is the weighted average position of the control point, or a NURBS curved surface whose shape is defined by the control point. .

  On the other hand, when the shape of the skin is calculated, the drawing unit draws a skin image representing the calculated shape of the skin in the line-of-sight direction from the viewpoint position on the already drawn image.

  When the shape of the skin is determined, the area in which the skin is to be drawn is determined. Therefore, drawing is performed by pasting a texture corresponding to the skin into an area where the skin is to be drawn in the storage area for storing the image.

  Further, when the skin image representing the shape of the skin calculated from the positions of the control points classified into groups for all the main bones is drawn, the display unit displays the already drawn image on the screen.

  Typically, after an image to be displayed is completed, a vertical synchronization interrupt is waited for, and after the vertical synchronization interrupt is generated, the screen is prevented from flickering by being transferred and displayed on the monitor screen.

  Here, the processing in the position calculation unit, skin calculation unit, and drawing unit is typically executed by an image processing coprocessor.

  In the present invention, the number of main bones and control points can be reduced by dividing the main bones and control points into a plurality of groups, thereby reducing the number of main bones and control points that must be considered in one drawing. Even when an image processor or the like that has limitations is used, the number of control points that can be processed can be increased in image generation.

  The image generation apparatus of the present invention further includes a buffer unit and can be configured as follows.

  That is, a background image prepared in advance is stored in the buffer unit.

  Here, the buffer unit is used to prevent flickering during drawing by a double buffering technique. That is, after the completed form of the image to be displayed on the screen is formed in the buffer unit, the image is transferred and displayed on a display screen such as a monitor, thereby preventing display flickering.

  On the other hand, the drawing unit draws the skin image so as to overlap the image already stored in the buffer unit, and the display unit displays the image stored in the buffer unit.

  According to the present invention, flickering of an image is less likely to occur, and a skin is drawn on a background image prepared in advance, so that calculation time can be spent on drawing the skin and a finer image can be obtained. .

  In the image generating apparatus of the present invention, the types of the plurality of bones include a secondary bone in addition to the primary bone, and each of the secondary bones is either one of the primary bones or any of the other secondary bones. Each of the plurality of control points, if the bone to which the relative position of the control point is fixed is a sub bone, the main bone on which the sub bone depends or other sub bone on which the sub bone depends Into a group for the main bone on which it depends.

  In the above invention, the control point is assumed to be fixed to any main bone, but in the present invention, the control point is fixed to either the main bone or the sub bone. However, if you follow the dependency relationship of the secondary bone, it will eventually reach one of the main bones, so even if the control point is fixed to the secondary bone, Will be classified.

  For example, when considering the point from the wrist of the character, the main bone defines the position and orientation of the palm, and the secondary bone defines the position and orientation of the finger. In addition, all the control points representing the shape beyond the wrist are classified into groups for the main bone of the palm.

  On the other hand, the image generation apparatus further includes a sub-update unit. Here, when the main bone is selected, the sub update unit determines the position and orientation of the sub bone depending on the selected main bone stored in the storage unit based on the passage of time or an instruction from the user. Update.

  As described above, when the relative position of the bone changes, the position or posture of the character or the like changes. When the main bone is selected, the position and orientation of the main bone in the virtual space are fixed. Therefore, the position and orientation of the sub bone depending on the main bone can also be determined. The sub-update unit performs this process.

  Further, when the position and orientation of the sub-bone are updated, the position calculation unit calculates the position in the virtual space of the control points classified into the group for the selected main bone.

  That is, the position calculation unit calculates the position in the virtual space of the control points classified into the group for the selected main bone after the position and orientation of the sub bone are updated.

  With this configuration, the drawing process is performed after all the positions of the sub-bones depending on the main bone for each group are determined.

  According to the present invention, while the drawing order of the group is simply calculated by the main bone, the fine shape change is performed by the sub bone, thereby generating a complex three-dimensional model image with a small amount of calculation. Will be able to.

  In the image generation device of the present invention, the selection unit can be configured to determine the order of the main bones in order of increasing depth distance from the viewpoint position.

  The present invention relates to a preferred embodiment of the above invention, and determines the order of main bones by the same method as the Z buffer method.

  According to the present invention, the drawing order of groups can be determined by simple calculation.

  Further, in the image generating apparatus of the present invention, some main bones are set to accompany other main bones, and the selection unit selects a main bone and accompanies the selected main bone. If there are other main bones to be selected, the other main bones to be accompanied can be selected at the same time.

  For example, when a character is displayed on the screen, an upper arm bone and a lower arm bone are associated with each other, and a thigh bone and a shin bone are associated with each other.

  The bent portion of the elbow or knee is a portion where problems such as twisting of the shape are likely to occur when expressed by polygons. In the present invention, the group skins for the main bones accompanying each other are simultaneously drawn in the buffer unit.

  Therefore, according to the present invention, it is possible to prevent the skin shape from becoming unnatural by appropriately defining the accompanying relationship of the main bone.

  In the image generating apparatus of the present invention, the skin is a polygon having a control point as a vertex, and a polygon having a control point as a vertex belonging to a plurality of different groups is selected by a main bone for any of the plurality of groups. Can be configured to be rendered.

  The present invention is an aspect in which the control point is a vertex of a polygon. A polygon consisting only of vertices belonging to a certain group is drawn when that group is selected.

  Therefore, if there are vertices belonging to different groups among the vertices of the polygon, drawing may be performed when the main bone for any group is selected.

  When a main bone for a group is selected, all polygons having apexes of control points belonging to the group may be drawn.

  The present invention relates to a preferred embodiment of the invention described above, and an image can be appropriately drawn by defining a skin with polygons having control points as vertices.

  Further, in the image generating apparatus of the present invention, the skin is a polygon having a vertex at a weighted average position of the position of the control point, and a polygon having a vertex at the weighted average position determined from control points belonging to a plurality of different groups is: It can be configured to be drawn by selecting a main bone for any of the plurality of groups.

  In the present invention, the positions of the vertices of the polygon are set as a weighted average of the positions of the control points, and the present invention can be considered as a special case of the present invention.

  Therefore, according to the present invention, an image can be drawn appropriately.

  In the image generation apparatus of the present invention, the selection unit simultaneously selects the next main bone in the order of the main bones unless the number of polygons to be drawn by selection by the selection unit exceeds a predetermined upper limit. It can be constituted as follows.

  In the present invention, as many groups as possible are processed simultaneously unless the number of polygons that can be processed at one time (approximately proportional to the number of control points) is exceeded.

  According to the present invention, even when the number of polygons and the number of control points that can be processed at one time are limited, it is possible to generate a three-dimensional model image exceeding these in as short a time as possible. .

  An image generation method according to another aspect of the present invention generates an image from a plurality of bones and a plurality of control points arranged in a virtual space.

  Here, when the position and orientation of a certain bone are determined relative to another bone, the certain bone depends on the other bone, and the position and orientation of the certain bone is determined with respect to the virtual space. The certain bone depends on the virtual space, and the position of each of the plurality of control points is fixed relative to one of the plurality of bones. There is a bone, and one of the main bones depends on the virtual space, each of the other main bones depends on one of the other main bones, and each of a plurality of control points When the bone to which the relative position of the control point is fixed is a main bone, it is classified into a group for the main bone.

  Furthermore, the image generation method is executed by an image generation apparatus including a storage unit, a main update unit, a buffer unit, a selection unit, a position calculation unit, a skin calculation unit, a drawing unit, and a display unit.

  The storage unit stores the relative position and orientation of each of the plurality of bones with respect to other bones on which the bone depends.

  On the other hand, a background image prepared in advance is stored in the buffer unit.

  Further, the image generation method includes a main update process, a selection process, a position calculation process, a skin calculation process, a drawing process, and a display process, and is configured as follows.

  Here, in the main update step, the main update unit updates the position and orientation of each main bone stored in the storage unit based on the passage of time or an instruction from the user.

  On the other hand, in the selection step, when the update is performed by the main update unit, the selection unit determines the order of the main bones based on the viewpoint position in the virtual space and the respective depths of the main bones with respect to the viewing direction. Select the main bones in order.

  Further, in the position calculation step, the position calculation unit calculates the position in the virtual space of the control points classified into a group for the selected main bone.

  In the skin calculation step, when the position of the control point is calculated, the skin calculation unit calculates the shape of the skin from the calculated position of the control point.

  On the other hand, in the drawing process, when the shape of the skin is calculated, the drawing unit has already stored the skin image representing the appearance of the calculated skin shape in the viewing direction from the viewpoint position in the buffer unit. Draw over the existing image.

  Further, in the display process, when a skin image representing the shape of the skin calculated from the positions of control points classified into groups for all main bones is drawn in the buffer unit, the display unit is stored in the buffer unit. Display the current image on the screen.

  A program according to another aspect of the present invention is configured to cause a computer to function as each unit of the image generation apparatus.

  The program of the present invention can be recorded on a computer-readable information storage medium such as a compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, and semiconductor memory.

  The above program can be distributed and sold via a computer communication network independently of the computer on which the program is executed. The information storage medium can be distributed and sold independently from the computer.

  According to the present invention, an image generation apparatus suitable for increasing the number of control points that can be processed in image generation from a three-dimensional model defined by bones and control points, an image generation method, and these are performed by a computer. A program to be realized can be provided.

It is a schematic diagram which shows schematic structure of a typical information processing apparatus. It is explanatory drawing which shows the condition of the bone of the model used as the process target of this embodiment, a control point, and a polygon. It is explanatory drawing which shows the method of determining the distance between a main bone and a viewpoint. It is explanatory drawing which shows schematic structure of the image generation apparatus which concerns on this embodiment. It is a flowchart which shows the flow of control of an image generation process. It is explanatory drawing which shows a mode that drawing is carried out to the buffer part. It is explanatory drawing which shows a mode that drawing is carried out to the buffer part. It is explanatory drawing which shows a mode that drawing is carried out to the buffer part. It is explanatory drawing which shows a mode that drawing is carried out to the buffer part. It is explanatory drawing which shows the mode of the group which considered the adjoint relationship.

  Embodiments of the present invention will be described below. In the following, for ease of understanding, an embodiment in which the present invention is realized using a game information processing device will be described. However, the embodiment described below is for explanation, and the present invention It does not limit the range.

  Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

  FIG. 1 is a schematic diagram illustrating a schematic configuration of a typical information processing apparatus that can function as an image generation apparatus according to the present embodiment by executing a program. Hereinafter, a description will be given with reference to FIG.

  An information processing apparatus 101 shown in the figure is a portable multimedia terminal, and includes a central processing unit (CPU) 102, a random access memory (RAM) 103, a read only memory (ROM) 104, an input device 105, and an image processing unit. 106, a liquid crystal display 107, an audio processing unit 108, headphones 109, a cassette reader 110, a ROM cassette 111, an external memory 112, an RTC (Real Time Clock) 113, a wireless LAN (Local Area Network) interface 114, and a camera 115.

  By mounting the ROM cassette 111 in which the program according to the present embodiment is recorded on the information processing apparatus 101, the image generation apparatus according to the present embodiment is realized.

  Here, the CPU 102 controls each unit of the information processing apparatus 101 and performs various arithmetic processes and determination processes.

  When the information processing apparatus 101 is turned on, the CPU 102 executes an IPL (Initial Program Loader) recorded in the ROM 104, and the ROM cassette 111 connected via the cassette reader 110 in the course of the processing. The process is transferred to the program recorded in

  The game program and multimedia information reproduction program executed by the information processing apparatus 101 are generally provided by the ROM cassette 111, but can be prepared in the ROM 104 in advance.

  Further, a program group called BIOS (Basic Input Output System) is prepared in the ROM 104, and the input device 105, the image processing unit 106, and the audio processing unit 108 can be controlled.

  The RAM 103 is an area for storing temporary information, and the external memory 112 is an area for storing nonvolatile information. As the external memory 112, a hard disk or the like that is mainly built in the information processing apparatus 101, or various memory cards or the like that are inserted into or removed from the information processing apparatus 101 may be used.

  The input device 105 is generally realized by various buttons, a keyboard, a mouse, a joystick, or the like, but a touch screen formed integrally with the liquid crystal display 107 can also be used as the input device 105. .

  The image processing unit 106 displays various character information and image information on the liquid crystal display 107 under the control of the CPU 102. In general, the image processing unit 106 has a vertical synchronization interrupt period (typically 1/30 second). And the pixel information stored in the frame buffer prepared in the RAM 103 is reflected on each pixel of the liquid crystal display 107 every time.

  In general, an instruction input from the user is performed by moving the cursor displayed on the liquid crystal display 107 by operating the move button of the input device 105, moving the cursor to a desired menu item, and selecting the menu item by operating the enter button. The cursor is not necessary when using a touch screen. Further, when the function assigned to each button of the input device 105 is determined in advance, the display on the liquid crystal display 107 is not necessarily required.

  The audio processing unit 108 outputs audio data prepared in the RAM 103, the ROM 104, the ROM cassette 111, and the external memory 112 to the headphones 109. As audio data, it is possible to use PCM (Pulse Code Modulation) data obtained by digitizing audio waveform data, MP3 (MPeg audio layer-3) data obtained by compressing PCM data to reduce the size, and the like. In addition, data such as MIDI (Music Instruction Data Interface) data that defines the pitch, tone length, volume, and timbre type is prepared, and the sound source waveform data prepared in advance is selected and transformed accordingly. It is also possible to adopt a method for reproducing the image.

  The RTC 113 measures the current date and time, and generally adjusts the time when the information processing apparatus 101 is used for the first time. The RTC 113 is connected to an NTP (Network Time Protocol) server via the wireless LAN interface 114. It is also possible to adopt a mode in which the time is automatically adjusted by connecting.

  There is also an RTC 113 having a function for generating an alarm interrupt. When the set time comes, an alarm interrupt occurs, and the CPU 102 temporarily suspends the currently executing program, executes a preset interrupt handler, and then resumes the interrupted program.

  The wireless LAN interface 114 is connected to the Internet via a wireless LAN access point prepared at home, company, or street corner, and establishes a communication path ad hoc with another information processing apparatus 101 disposed in the vicinity. It is possible to communicate one-on-one.

  The camera 115 realizes the function of a digital camera by the information processing apparatus 101, and a technique such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be applied. The captured image is temporarily expanded in the RAM 103 and then stored in the external memory 112 or the like.

  In addition, the image generating device of the present invention is realized for business computers, mobile phones, PDAs (Personal Data Assistant), portable game devices, multi-function television devices, DVD (Digital Versatile Disc) players, portable music players, and the like. It can also be employed as an information processing apparatus.

(Model for image generation)
FIG. 2 is an explanatory diagram illustrating the appearance of bones, control points, and polygons of a model to be processed in the present embodiment. Hereinafter, a description will be given with reference to FIG.

In the model 201 shown in the figure, the position, posture, and outer shape of the character are expressed by the following main bones 202.
(1) Main bone 202a representing the head
(2) Main bone 202b representing the upper body
(3) A main bone 202c representing the upper right arm and a main bone 202d representing the right lower arm
(4) A main bone 202e representing the upper left arm and a main bone 202f representing the lower left arm
(5) Main bone 202g representing the right palm
(6) Main bone 202h representing the left palm
(7) Main bone 202i representing the lower body
(8) A main bone 202j representing the right thigh and a main bone 202k representing the right shin
(9) Main bone 202l representing the left thigh and main bone 202m representing the left shin
(10) Main bone 202n representing the right sole
(11) Main bone 202o representing the left sole

  The main bones 202 are connected at their end points, for example, as the main bone 202c for the upper right arm and the main bone 202d for the lower right arm, or are, for example, the main bone 202b at the upper body and the main bone 202c for the upper right arm In addition, the end point of the other main bone 202 is connected to a connection point (corresponding to the position of the right shoulder) whose position with respect to one main bone 202 is fixed.

  Further, in the model 201, a fine posture of the character is expressed by a plurality of secondary bones 203g representing fingers of the right hand and a plurality of secondary bones 203h representing fingers of the left hand.

  The secondary bone 203 (the bone of each joint of the finger in this embodiment) is directly connected to one of the main bones 202 (the palm bone in this embodiment) or indirectly through another secondary bone 203. Connected to the main bone 202. Also in this case, the connection point may be on the bones 202 and 203 or may be at a fixed position with respect to the bones 202 and 203.

  The bones 202 and 203 that are connected to each other have their relative positions and orientations defined, whereby the overall posture of the character is determined.

  Further, by determining the position and orientation of one of the main bones 202 (typically, the main bone 202b representing the upper part of the body) in the virtual space, the overall position and orientation of the character are determined. Hereinafter, in order to facilitate understanding, it is assumed that the main bone 202 depends on the virtual space.

  Furthermore, for ease of understanding, when there are other bones 202, 203 that are connected to one bone 202, 203 and have a relative position and orientation relative thereto, the latter depends on the former and the former depends on the latter. It is said that it depends. The former is the parent bone and the latter is the child bone.

  For example, the main bone 202c on the upper right arm depends on the main bone 202b on the upper body, the main bone 202d on the lower right arm depends on the main bone 202c on the upper right arm, and the main bone of the right palm on the main bone 202d on the right lower arm. 202g depends on it, and the right bone sub-bone 203g depends on the right palm main bone 202g. Dependencies are also defined in order for the right-hand finger sub-bones 203g, and the far side depends on the side closer to the right palm main bone 202g.

  Considering this, all the secondary bones 203 depend on any one main bone 202.

  The main bone 202 and the secondary bone 203 play the same role as bones in the conventional three-dimensional graphics technology, and a control point 204 is fixed to each of them. In this figure, only a part of the control points 204 is shown for easy understanding.

  Furthermore, as disclosed in Patent Document 1, the sub-bone 203 is adopted as a bone for opening and closing the mouth and the eyelid, and as disclosed in Patent Document 3, the elbow, knee, and other parts that are easily constricted. It is also possible to employ the secondary bone 203 as a bone for maintaining the thickness.

  In addition, the control point 204 is fixed to either the main bone 202 or the sub bone 203 and moves in the virtual space in conjunction with the fixing destination.

  In the present embodiment, the control point 204 is a vertex of the polygon 205, and this polygon 205 forms a skin representing the surface of the model 201.

  Here, a control point 204 fixed to a certain main bone 202 and a control point 204 fixed to a secondary bone 203 depending on the main bone 202 are referred to as “control points 204 belonging to a group for the main bone 202. Or abbreviated as “control point 204 belonging to the main bone 202”.

  For example, the shape of the upper part of the fuselage is determined by a polygon 205 whose apex is the control point 204 belonging to the upper main bone 202b, and the polygon 205 whose apex is the control point 204 belonging to the group for the main palm 202g of the right palm, The shape of the palm and fingers of the right hand is determined.

  Instead of using the coordinates of the control point 204 as the vertices of the polygon 205 as they are, one or more control points 204 are assigned to each of the vertices of the polygon 205 together with a weight, and the weight of the position of the assigned control point 204 is added. A method of setting the average position as the vertex of the polygon 205 has also been widely used in the past, and such a mode can also be adopted.

  Also, instead of defining the shape of the skin by the polygon 205, a mode in which the surface of the model 201 is expressed smoothly by using the control point 204 as a control point for determining the shape of the NURBS curved surface is adopted. Also good.

  In (3), (4), (8), and (9), two main bones 202 are listed, and the two main bones 202 are associated with each other. Here, the main bones 202 accompanying each other are appropriate when the control points defined by the main bones 202 are closely related to each other. In this embodiment, in order to appropriately determine the skin shape such as the elbow and the knee by applying the technique disclosed in Patent Document 3 as described above, the accompanying relationship is determined.

  Depending on the types of objects that change the position, orientation, and shape in the virtual space, such as various characters represented by the model 201, it is possible that there is no secondary bone 203 or any accompanying relationship. These embodiments are also included in the scope of the present invention.

  In this way, the model 201 is defined by the bones 202 and 203, the control point 204, and the polygon 205.

  In contrast to such a model 201, in the conventional three-dimensional graphics, all polygons 205 are sorted according to the distance from the viewpoint, and the Z-buffer technique is used to draw the polygons in order from the farthest polygon 205. The relationship of hiding and hiding each other was appropriately reflected in the image.

  On the other hand, in this embodiment, the polygon 205 is classified according to the group of the main bone 202 to which the polygon 205 belongs. In the present embodiment, as described above, the polygons 205 are classified into 11 groups.

Then, the main bone 202 is sorted by the distance from the viewpoint. For example, in the example shown in FIG. 2, when the main bones 202 are arranged in order from the viewpoint, the result is as follows.
(1) Left palm main bone 202h
(2) Main bone 202f of the left lower arm
(3) Left foot sole main bone 202o
(4) Left shin main bone 202m
(5) Left upper arm main bone 202e
(6) Left thigh main bone 202l
(7) Main bone 202a of the head
(8) Main bone 202b at the top of the fuselage
(9) Main bone 202i at the bottom of the fuselage
(10) Right thigh main bone 202j
(11) Main bone 202k of right shin
(12) The main bone 202c of the upper right arm
(13) Lower right arm main bone 202d
(14) Right foot sole main bone 202n
(15) Right palm main bone 202g

  Then, the main bone 202 is selected in order from the main bone 202 far from the viewpoint, and the following processing is repeated. In the above example, since there are 15 main bones 202, the following processing is repeated 15 times.

  That is, the Z buffer technique is used only for the polygon 205 belonging to the selected group of the main bones 202. That is, only the polygons 205 belonging to the group are sorted by the distance from the viewpoint, and are drawn in order from the farther polygon 205.

  For example, in the first iteration, the left palm main bone 202h farthest from the viewpoint is selected. Then, the position of the control point 204 representing the shape of the left hand is calculated based on the main bone 202h of the left palm and the secondary bone 202 representing the finger of the left hand.

  Further, based on the calculated position of the control point 204, the shape of the polygon 205 representing the shape of the left palm or the finger of the left hand is calculated and drawn, so that the skin ahead from the left wrist It is formed.

  Hereinafter, the second iteration is drawn from the left elbow to the left wrist based on the left lower arm main bone 202f, and the third iteration is the left foot sole drawn based on the left foot main bone 202o. ... The process of drawing the polygon 205 in units of groups is repeated.

  In the present embodiment, the entire polygon 205 is not processed at once, but is divided into groups and processed. For this reason, the number of bones 202 and 203 that must be processed at one time, the number of control points 204, and the number of polygons 205 can be suppressed.

  Therefore, even when the capability of the image processing coprocessor constituting the image processing unit 106 is low, an image composed of a large number of control points 204 and polygons 205 can be generated.

  In order to facilitate understanding, the drawing is repeated here in units of groups of the main bone 202. However, an adjoint relationship is introduced into the main bone 202, and one group and another group (for example, the main body of the left lower arm). If the bone 202f and the main bone 202e of the upper left arm are associated with each other), it is possible to reduce the possibility of inconsistency in polygon drawing, and to reduce the ability of the image processing coprocessor as much as possible. In many cases, it is preferable in terms of drawing. Hereinafter, an example in which such an accompanying relationship is introduced will be described.

  As described above, in this embodiment, the order of drawing the group of polygons 205 is determined using the perspective information between the main bone 202 and the viewpoint. Hereinafter, how to obtain the distance between the main bone 202 and the viewpoint will be described.

  FIG. 3 is an explanatory diagram showing a method for determining the distance between the main bone 202 and the viewpoint. Hereinafter, a description will be given with reference to FIG.

  In the figure, two main bones 202p and 202q and a viewpoint 301 are shown.

  The main bones 202p and 202q shown in the figure are connected by a connection point 302.

  In addition, center points 303p and 303q are defined at the center of the main bones 202p and 202q.

  Which of the two main bones 202p and 202q is closer to the viewpoint 301 can be determined by the following criteria.

  The first criterion is a method that employs the distance between each of the center points 303p and 303q of the main bones 202p and 202q and the viewpoint 301.

  That is, the distance 305p between the viewpoint 301 and the center point 303p and the distance 305q between the viewpoint 301 and the center point 303q are calculated based on the Euclidean distance or the Manhattan distance. Of the main bones 202p and 202q, the longer distance calculated for the center point is farther from the viewpoint 301 and the shorter distance is closer.

  The second criterion is a criterion that can be used when the two main bones 202 whose perspectives are to be compared are connected to each other.

That is, the following two angles are compared.
(P) an angle P from the viewpoint 301 through the connection point 302 to the center point 303p,
(Q) An angle Q from the viewpoint 301 through the connecting point 302 to the center point 303q.

  The angles P and Q are values indicating the orientation of the main bones 202p and 202q with respect to the viewpoint 301.

  It can be considered that the two main bones 202p and 202q connected at one connection point 302 have little difference in distance from the viewpoint 301. Accordingly, since the main bones 202p and 202q are generally different in length, if the distance between the center points 303p and 303q and the viewpoint 301 is simply adopted, the depth order may be erroneously determined. .

  According to the second criterion, even if the main bones 202p and 202q connected to each other have different lengths, the depth context can be easily determined.

  As described above, the first criterion can be employed to determine the depth-direction context of any main bone 202, and the second criterion can be the depth-direction of main bones 202 connected to each other. It can be used to determine the context.

  Further, after determining the order of the main bones 202 that are directly connected based on the second standard, since the direct connection is not performed, the main bones 202 whose context is not determined only by the second standard are as follows. There may be a method of determining the depth order based on the first criterion.

  As described above, only the first criterion may be adopted depending on the shape of the model 201 and the application to be applied, or both criteria may be appropriately adopted.

  Below, the image generation apparatus using these methods and the detail of the image generation process which this performs are demonstrated.

(Image generation device)
FIG. 4 is an explanatory diagram showing a schematic configuration of the image generation apparatus according to the present embodiment. Hereinafter, a description will be given with reference to FIG.

  The image generation apparatus 401 according to the present embodiment is realized by the CPU 102 executing a predetermined program in the information processing apparatus 101.

  Here, the image generation apparatus 401 includes a storage unit 402, a main update unit 403, a buffer unit 404, a selection unit 405, a sub update unit 406, a position calculation unit 407, a skin calculation unit 408, a drawing unit 409, and a display unit 410. .

  Hereinafter, first, the function of each unit will be briefly described, and then the details of the function of each unit will be described along the flow of processing executed by the image generation apparatus 401.

  First, the storage unit 402 is realized by the RAM 103 that reads information stored in the ROM cassette 111 and the like, and various types of information of the model 201 are stored in the storage unit 402.

  On the other hand, the buffer unit 404 is realized by a storage area prepared in the RAM 103 or the image processing unit 106 and is used as a temporary storage area for generating an image to be displayed on the liquid crystal display 107.

  Further, the main update unit 403 is realized by the CPU 102 or when the image processing unit 106 operates under the control of the CPU 102, and changes the position and orientation of the main bone 202 constituting the model 201.

  The secondary update unit 406 is realized by the CPU 102 or by the image processing unit 106 operating under the control of the CPU 102, and changes the position and orientation of the secondary bone 203 constituting the model 201.

  The position calculation unit 407 is realized by the operation of the image processing unit 106 under the control of the CPU 102, and the position of the control point 204 constituting the model 201 is determined based on the position and orientation of the main bone 202 and the sub bone 203. calculate.

  The skin calculation unit 408 is realized by the operation of the image processing unit 106 under the control of the CPU 102, and calculates the position and shape of the polygon 205 constituting the model 201 based on the position of the control point 204.

  The drawing unit 409 is realized by the operation of the image processing unit 106 under the control of the CPU 102. The polygon 205 whose position and shape have been calculated is obtained as a projected area, and a texture associated with the polygon 205 is obtained. Then, the pasting process is performed while deforming the region.

  The selection unit 405 sorts the main bones 202 according to the distance from the viewpoint 301 and sequentially selects the main bones 202 in order from the viewpoint 301.

  Then, the processing by the sub-update unit 406, the position calculation unit 407, the skin calculation unit 408, and the drawing unit 409 includes the sub-bone 203 depending on the selected main bone 202, the control point 204 belonging to the selected main bone 202, Only the polygon 205 having the control point 204 as a vertex is performed.

  As described above, in the present embodiment, drawing is not performed for all the polygons 205 at once, but drawing is performed sequentially for each group to which the polygons 205 belong.

  That is, the processes in the sub-update unit 406, the position calculation unit 407, the skin calculation unit 408, and the drawing unit 409 are performed in units of groups for the selected main bone 202.

  For this reason, even if there is a limitation on the rendering capability of the image processing coprocessor in the image processing unit 106, the number of bones 202 and 203, the number of control points 204, and the number of polygons 205 exceed the limitation. Thus, 201 images can be generated.

  The display unit 410 is realized by the image processing unit 106, waits until a vertical synchronization interrupt occurs after the image for the model 201 is completed, and then transfers and displays the image stored in the buffer unit 404 on the liquid crystal display 107. To do.

  Hereinafter, an image generation process executed by the image generation apparatus 401 will be described in detail. FIG. 5 is a flowchart showing the flow of control of image generation processing. Hereinafter, a description will be given with reference to FIG.

  In the present embodiment, this process is realized by the CPU 102 executing a program recorded in the ROM cassette 111.

When this process is started, the CPU 102 initializes information stored in the RAM 103 (step S501). Here, the RAM 103 stores the following information.
(A) The dependence destination (link destination) of each main bone 202, the relative position and orientation with respect to the dependence destination, the length of the main bone 202, and the accompanying destination of the main bone 202.
(B) The connection destination of each secondary bone 203, the dependence destination, the relative position and orientation with respect to the connection destination, and the length of the secondary bone 203.
(C) Which bones 202 and 203 each control point 204 is fixed to, the relative position where the control point 204 is fixed, and the main bone 202 for the group to which the control point 204 belongs Or?
(D) Which of the control points 204 is the vertex of each polygon 205.
(E) A background image representing the background of the model 201.
(F) Virtual time in the virtual space where the model 201 is placed.

  That is, the RAM 103 functions as the storage unit 402.

  The initial values of these pieces of information are typically recorded in the ROM cassette 111 or the external memory 112, but are generated by random numbers, acquired via the wireless LAN interface 114, or via the input device 105. Various methods such as setting based on an instruction from the user are conceivable.

  Next, the CPU 102 updates the information on the relative position and orientation of the main bone 202 among the information stored in the RAM 103 according to the virtual time. A specific position and orientation are calculated and updated (step S502). That is, the CPU 102 functions as the main update unit 403. Note that the function of the image processing coprocessor included in the image processing unit 106 may be used for this calculation.

  Although depending on the design of the model 201, generally, the number of the main bones 202 is almost smaller than the number of the secondary bones 203, and the calculation in step S502 is short.

  Further, the CPU 102 calculates the depth distance from the viewpoint 301 based on the absolute position / orientation of each main bone 202, and sorts them in order of increasing distance (step S503).

  Next, the CPU 102 controls the image processing unit 106 to draw a predetermined background image in the buffer unit 404 (step S504). This background image represents the background of the model 201 in the virtual space. Although a method of forming the background of the model 201 using polygons can be adopted, in this embodiment, since the polygon processing function is desired to be used for drawing the model 201 as much as possible, the background image is drawn and drawn in a play tool. As shown, one picture is prepared in advance.

  The buffer unit 404 may be prepared in the RAM 103 or may be prepared in the image processing unit 106 as a drawing storage area.

  Then, the CPU 102 refers to the sorted order and repeats the following process until all the main bones 202 are selected (step S505).

  First, the CPU 102 selects the main bone 202 farthest from the viewpoint 301 among the main bones 202 not yet selected (step S506). At this time, if there is another main bone 202 associated with the main bone 202, the accompanying main bone 202 is also selected.

  Next, the CPU 102 acquires the main bone 202 farthest from the viewpoint 301 (that is, the next main bone 202 next to the next) among the remaining main bones 202 that have not yet been selected (step S507). At this time, if there is another main bone 202 accompanying the acquired main bone 202, the accompanying main bone 202 is also acquired.

  Then, the CPU 102 counts the number of selected main bones 202, the number of sub-bones 203 depending on the selected main bone 202, the number of control points 204 belonging to the group for the selected main bone 202, the selection In addition to the number of polygons 205 having apexes of the control points 204 belonging to the completed main bone 202, the number of main bones 202 acquired in step S506, the number of sub-bones 203 depending on the acquired main bone 202, the acquisition An image of the image processing unit 106 is obtained by adding the number of control points 204 belonging to the group for the main bone 202 and the number of polygons 205 having the acquired control points 204 belonging to the main bone 202 as vertices. It is checked whether or not the processing coprocessor is within the limits (step S508).

  If within the limit (step S508; Yes), the CPU 102 further selects the acquired main bone 202 (step S509), and returns to step S507.

  On the other hand, if the limit is exceeded (step S508; No), the CPU 102 proceeds to step S511. In this case, the acquired main bone 202 is not selected this time, but is selected and drawn in the next iteration.

  As described above, the CPU 102 functions as the selection unit 405.

  By providing such a restriction, the main bone 202 selected here and the sub-bone 203, the control point 204, and the polygon 205 related to the main bone 202 are collected at once by the image processing coprocessor of the image processing unit 106. Thus, the number of drawing processes can be limited within a single vertical synchronization period. Therefore, even the information processing apparatus 101 with a low processing capability, such as a portable terminal, can perform drawing.

  Next, the CPU 102 displays information on the relative position and orientation of the sub-bone 203 depending on the selected main bone 202 among the positions and orientations of the selected main bone 202 depending on the virtual time. While updating in the RAM 103, the absolute position and orientation of the secondary bone 203 in the virtual space are calculated (step S511).

  Since these bone operations require coordinate transformation, it is common to leave the operation to the image processing coprocessor. In this embodiment, however, the calculation of the position of the sub-bone 203 is divided into groups. By doing so, the calculation load per time can be reduced.

  As described above, the image processing unit 106 functions as the sub-update unit 406 under the control of the CPU 102.

  Further, the CPU 102 calculates the absolute position of each control point 204 belonging to the selected group in the virtual space based on the position and orientation of the sub bone 203 of the main bone 202 (step S512).

  Since these position calculation calculations also require coordinate conversion, it is common to leave the calculation to the image processing coprocessor. In this embodiment, however, the calculation of the position of the control point 204 is divided into groups. By doing so, the calculation load per time can be reduced.

  As described above, the image processing unit 106 functions as the position calculation unit 407 under the control of the CPU 102.

  Next, under the control of the CPU 102, the image processing unit 106 sorts the polygons 205 having the respective control points 204 belonging to the selected group as vertices by the distance from the viewpoint 301 (step S513). The following processing is repeated in the order of increasing distance (step S514). This corresponds to drawing by the so-called Z buffer method.

  That is, the image processing unit 106 calculates the shape of the polygon 205 to be processed, and calculates the area projected in the buffer unit 404 (step S515).

  At this time, the position of the viewpoint 301 arranged in the virtual space, the direction of the line of sight, and the like are referred to, and the area calculation is performed by parallel projection or perspective projection.

  Next, the image processing unit 106 pastes the texture information assigned to the polygon 205 in the calculated area in the buffer unit 404 and performs drawing (step S516).

  This process is repeated for all the polygons 205 belonging to the selected main bone 202 in the order farthest from the viewpoint 301 (step S517).

  Therefore, the image processing unit 106 functions as the skin calculation unit 408 and the drawing unit 409.

  In this way, when the drawing of the group related to the selected main bone 202 is completed, the ability of the image processing coprocessor in one vertical synchronization cycle is exhausted.

  Therefore, the CPU 102 waits for a vertical synchronization interrupt (step S519). During this standby, other calculation processes can be executed in a coroutine manner as appropriate.

  Then, the processes after step S505 are repeated until all the main bones 202 are selected (step S520).

  6, 7, 8, and 9 are explanatory diagrams showing how the image stored in the buffer unit 404 is updated by repeating the processes in steps S <b> 505 to S <b> 520. Hereinafter, a description will be given with reference to FIG.

  FIG. 6 shows a state in which only the initial background image 501 is drawn.

FIG. 7 shows an image after the first iteration has been completed. On the background image 501 in FIG.
(B1) Left arm skins 601e and 601f formed by polygons 205 belonging to main bones 202e and 202f
(B2) Left palm skin 601h formed by polygon 205 belonging to main bone 202h
(B3) Left thigh skin 601l and left shin skin 601m formed by polygon 205 belonging to main bones 202l and 202m
(B4) Skin 601o of the left sole formed by the polygon 205 belonging to the main bone 202o
Is drawn.

FIG. 8 shows an image after the next stage of drawing has been completed.
(C1) Head skin 601a formed by polygon 205 belonging to main bone 202a
(C2) The upper skin 601b formed by the polygon 205 belonging to the main bone 202b
(C2) Skin 601i under the trunk formed by the polygon 205 belonging to the main bone 202i
Is drawn.

FIG. 9 shows an image after the final stage of drawing is completed. On the image of FIG.
(D1) Skins 601c, 601d for the right arm formed by the polygon 205 belonging to the main bones 202c, 202d,
(D2) The right palm skin 601g formed by the polygon 205 belonging to the main bone 202g,
(D3) The right thigh skin 601j and the right shin skin 601k formed by the polygon 205 belonging to the main bones 202j and 202k.
(B4) The skin 601n of the right sole formed by the polygon 205 belonging to the main bone 202n,
Is drawn.

  Since the polygons to be processed in one drawing are sorted and drawn by the distance from the viewpoint 301 by the Z buffer method, there is no contradiction in the positional relationship in the depth direction.

  In the model 201, the positions and orientations that the main bone 202 can take are often restricted in order to imitate a joint of a living organism or avoid the intersection of the main bone 202. For this reason, regarding the positional relationship between the groups in the depth direction, it is considered that there is practically no contradiction based on the method of this embodiment.

  In this embodiment, since the polygon 205 is assigned to each group of 15 main bones 202, the total number of groups is 15. However, this embodiment introduces an accompanying relationship to the right arm, right leg, left arm, and left leg. For this reason, the number of substantial groups is 11.

  FIG. 10 is an explanatory diagram showing the state of the group in consideration of the adjoint relationship. Hereinafter, a description will be given with reference to FIG.

  The skins of the model 201 are substantially classified into 11 groups 209 as depicted by the bold lines in the figure. One or more main bones 202 are assigned to each group 209, and the group 209 to which a plurality of main bones 202 are assigned can be bent at a joint.

  In this manner, the classification and introduction of the adjoint relationship into the group 209 can be appropriately changed according to the shape of the character, the number of polygons 205, the performance of the image processing coprocessor, and the like. For example, various modes are conceivable, such as introducing an adjoint relationship in which the head, the upper part of the trunk, and the lower part of the trunk are combined.

  In this way, when all the main bones 202 are selected and drawing is completed, the processing from step S505 to step S520 is terminated. This timing corresponds to immediately after the vertical synchronization interrupt.

  Therefore, the CPU 102 controls the image processing unit 106 to transfer and display the image drawn in the buffer unit 404 on a display screen of a monitor such as the liquid crystal display 107 (step S521).

  Therefore, the CPU 102 functions as the display unit 410 in cooperation with the image processing unit 106.

  Next, the CPU 102 causes the virtual time in the RAM 103 to elapse for the time required to repeat the current step S505 to step S520 (step S522), and returns to step S504.

  This virtual time is referred to when the model 201 is deformed when the model 201 is deformed according to a predetermined algorithm as time passes.

  The main update unit 403 and the sub update unit 406 perform deformation calculation of the model 201. In this calculation, the posture and position of the model 201 may be deformed by combining the information captured in advance with the passage of virtual time. Alternatively, the model 201 may be deformed based on an operation instruction from the player.

  By performing the above iterative process, the image of the model 201 designed with a large number of polygons 205 can be generated and presented to the user while sacrificing the frame rate of the screen update. is there.

  As described above, according to the present invention, an image generation apparatus, an image generation method, and an image generation apparatus suitable for increasing the number of control points that can be processed in image generation from a three-dimensional model defined by bones and control points, and A program for realizing these by a computer can be provided.

101 Information processing apparatus 102 CPU
103 RAM
104 ROM
105 Input Device 106 Image Processing Unit 107 Liquid Crystal Display 108 Audio Processing Unit 109 Headphone 110 Cassette Reader 111 ROM Cassette 112 External Memory 113 RTC
114 Wireless LAN Interface 115 Camera 201 Model 202 Main Bone 203 Secondary Bone 204 Control Point 205 Polygon 209 Group 401 Image Generation Device 402 Storage Unit 403 Main Update Unit 404 Buffer Unit 405 Selection Unit 406 Sub Update Unit 407 Position Calculation Unit 408 Skin Calculation Unit 409 Drawing unit 410 Display unit 501 Background image 601 Skin

Claims (10)

An image generation device that generates an image from a plurality of bones and a plurality of control points arranged in a virtual space,
If the position and orientation of a bone is defined relative to another bone, that bone depends on the other bone,
If the position and orientation of a bone is defined with respect to the virtual space, the bone depends on the virtual space,
Each of the plurality of control points is fixed in a relative position with respect to any of the plurality of bones.
The multiple bone types include a main bone,
Any one of the main bones depends on the virtual space, and each of the other main bones depends on any other main bone,
Each of the plurality of control points is classified into a group for the main bone when the bone to which the relative position of the control point is fixed is the main bone.
The image generation device includes:
For each of the plurality of bones, a storage unit that stores a relative position and orientation with respect to other bones on which the bone depends,
A main update unit that updates the position and orientation of each main bone stored in the storage unit based on the passage of time or an instruction from the user,
When updated by the main update unit, the order of the main bones is determined based on the viewpoint position in the virtual space and the respective depths of the main bones with respect to the line-of-sight direction, and the main bones are determined in the determined order. A selection part that selects bones in order,
A position calculation unit for calculating a position in the virtual space of control points classified into a group for the selected main bone;
When the position of the control point is calculated, a skin calculation unit that calculates the shape of the skin from the calculated position of the control point,
When the shape of the skin is calculated, a drawing unit that draws a skin image representing the shape of the calculated skin viewed in the line-of-sight direction from the viewpoint position, overlaid on the already drawn image,
When a skin image representing the shape of the skin calculated from the positions of control points classified into groups for all main bones is drawn, the display unit displays the already drawn image on the screen. An image generating apparatus. The image generation apparatus according to claim 1,
A buffer unit for storing a background image prepared in advance;
The drawing unit draws the skin image so as to overlap the image already stored in the buffer unit,
The display unit displays an image stored in the buffer unit. The image generating apparatus according to claim 1 or 2,
There are sub-bones in addition to the main bone in the multiple bone types.
Each of the secondary bones depends on any primary bone or any other secondary bone,
Each of the plurality of control points depends on a main bone on which the sub bone depends or another sub bone on which the sub bone depends if the bone to which the relative position of the control point is fixed is a sub bone. Into a group for the main bone
The image generation device includes:
When the main bone is selected, a sub-update unit that updates the position and orientation of the sub-bone depending on the selected main bone stored in the storage unit based on the passage of time or an instruction from the user Further comprising
When the position and orientation of the sub-bone are updated, the position calculation unit calculates a position in the virtual space of control points classified into a group for the selected main bone. . The image generation apparatus according to any one of claims 1 to 3,
The selection unit determines the order of the main bones in order of increasing depth distance from the viewpoint position. The image generation apparatus according to any one of claims 1 to 3,
Some of the main bones are set to accompany other main bones,
The selection unit selects a certain main bone, and when there is another main bone accompanying the selected main bone,
An image generation apparatus characterized by simultaneously selecting other accompanying main bones. The image generation apparatus according to any one of claims 1 to 5,
The skin is a polygon whose vertex is the control point, and the polygon whose vertex is a control point belonging to a plurality of different groups is drawn by selecting a main bone for any of the plurality of groups. An image generation apparatus characterized by the above. The image generation apparatus according to any one of claims 1 to 5,
The skin is a polygon whose vertex is a weighted average position of the control point positions, and the polygon whose vertex is a weighted average position determined from control points belonging to a plurality of different groups corresponds to any of the plurality of groups. An image generating apparatus characterized by being drawn by selecting a main bone. The image generation apparatus according to claim 6, wherein:
The selection unit simultaneously selects the next main bone in the order of the main bones unless the number of polygons to be drawn by the selection by the selection unit exceeds a predetermined upper limit. . An image generation method for generating an image from a plurality of bones and a plurality of control points arranged in a virtual space,
If the position and orientation of a bone is defined relative to another bone, that bone depends on the other bone,
If the position and orientation of a bone is defined with respect to the virtual space, the bone depends on the virtual space,
Each of the plurality of control points is fixed in a relative position with respect to any of the plurality of bones.
The multiple bone types include a main bone,
Any one of the main bones depends on the virtual space, and each of the other main bones depends on any other main bone,
Each of the plurality of control points is classified into a group for the main bone when the bone to which the relative position of the control point is fixed is the main bone.
The image generation method is executed by an image generation apparatus having a storage unit, a main update unit, a selection unit, a position calculation unit, a skin calculation unit, a drawing unit, and a display unit,
The storage unit stores, for each of the plurality of bones, a relative position and orientation with respect to other bones on which the bone depends,
The image generation method includes:
The main update unit updates the position and orientation of each main bone stored in the storage unit based on the passage of time or an instruction from the user,
When updated by the main update unit, the selection unit determines the order of the main bones based on the viewpoint position in the virtual space and the respective depths of the main bones with respect to the line-of-sight direction, and is determined A selection step of sequentially selecting the main bones in order;
A position calculation step in which the position calculation unit calculates a position in the virtual space of control points classified into a group for the selected main bone;
When the position of the control point is calculated, the skin calculation unit calculates a skin shape from the calculated position of the control point,
When the shape of the skin is calculated, the drawing unit draws the skin image representing the shape of the calculated skin viewed from the viewpoint position in the line-of-sight direction, overlaid on the already drawn image. Drawing process,
When a skin image representing the shape of a skin calculated from the positions of control points classified into groups for all main bones is drawn, the display unit displays the already drawn image on the screen. An image generation method comprising: A program for causing a computer to generate an image from a plurality of bones and a plurality of control points arranged in a virtual space,
If the position and orientation of a bone is defined relative to another bone, that bone depends on the other bone,
If the position and orientation of a bone is defined with respect to the virtual space, the bone depends on the virtual space,
Each of the plurality of control points is fixed in a relative position with respect to any of the plurality of bones.
The multiple bone types include a main bone,
Any one of the main bones depends on the virtual space, and each of the other main bones depends on any other main bone,
Each of the plurality of control points is classified into a group for the main bone when the bone to which the relative position of the control point is fixed is the main bone.
The program causes the computer to
For each of the plurality of bones, a storage unit that stores a relative position and orientation with respect to other bones on which the bone depends,
A main update unit that updates the position and orientation of each main bone stored in the storage unit based on the passage of time or an instruction from the user,
When updated by the main update unit, the order of the main bones is determined based on the viewpoint position in the virtual space and the respective depths of the main bones with respect to the line-of-sight direction, and the main bones are determined in the determined order. A selection part that selects bones in order,
A position calculation unit for calculating a position in the virtual space of control points classified into a group for the selected main bone;
When the position of the control point is calculated, a skin calculation unit that calculates the shape of the skin from the calculated position of the control point,
When the shape of the skin is calculated, a drawing unit that draws a skin image representing the shape of the calculated skin viewed in the line-of-sight direction from the viewpoint position, overlaid on the already drawn image,
When a skin image representing the shape of the skin calculated from the positions of control points classified into groups for all main bones is drawn, the already drawn image can be made to function as a display unit that is displayed on the screen. A featured program.

Images