JP4117497B2 - Image processing apparatus, image processing method, and recording medium - Google Patents

Description

  The present invention relates to an image processing technique suitable for a game device that provides an image in a three-dimensional virtual space. In particular, the present invention provides image processing that can draw a player deeply into the game world by displaying images displayed in a role-playing game with a rich sense of realism or giving natural image changes. .

  Among video game devices, role-playing games using three-dimensional image processing technology are popular due to the beauty of the images and the depth of stories. Many role-playing games are configured to display a number of objects to be displayed (hereinafter referred to as “objects”) arranged in a three-dimensional virtual space by applying a computer graphics technique. Examples of the object include a model of a main character of a role playing game and a person appearing in the game (hereinafter referred to as a “character”), in addition to a model of a natural world such as terrain, plants, animals, and buildings. In this game apparatus, the character corresponding to the main character is configured to be able to move in the virtual space in response to the operation of the input device performed by the player. Then, the game device develops the game story while accompanying the viewpoint for displaying the image of the virtual space according to the movement of the hero character, and moves the object in the virtual space together with the character. It will be displayed.

  In the conventional role-playing game, since the state of the virtual space must be clearly presented to the player, the object display method has been devised. For example, when a character goes in and out of an object simulating a building, a part of the building is made transparent or an object without a roof is used to make it easy to see the movement of the character entering the building.

  If the object is a model of a tree, the texture of the entire tree is represented on a single plane polygon, or a polygon with a texture mapped to represent leaves is inserted into the center of the trunk in a cross shape. In this way, texture data is mapped on the polygon to make it look like a tree by combining or expressing a tree with a ball-like object.

  In addition, a shadow that moves as the character moves may be displayed to enhance the sense of reality.

  However, it is preferable that the role playing game is designed so that the player can be immersed in the video world provided by the game device and can be assimilated mentally with the main character. When the conventional role-playing game is evaluated from such a viewpoint, there are some disadvantages.

  For example, in a game device in which a part of the building was erased when the character entered the building, the part of the building suddenly disappeared or the screen switched to the display in the house, making it unnatural. Occasional discomfort for players during play. In addition, if the building roof is omitted from the beginning and displayed, it is far from a realistic image, so it was not possible to enhance the presence.

  Further, in the role playing game, where the character goes depends on the player's operation, there is a case where the character is extremely close to the object. However, if the object that the character approached was a model of a tree by a conventional method, the shape of the microscopic object was far from the shape of the actual tree, so it looks like an unnatural image. It was.

  However, even if it is expressed as an individual polygon for each leaf, it cannot be handled by a game machine that has great restrictions on machine performance and processing time.

  Further, in the conventional method of displaying shadows, a black disk-like object is placed under the character's feet, and both objects are moved together to display the shadow. However, in order to prevent the shadow object from sinking into the ground when the terrain is uneven, a method having a high calculation load such as floating the shadow object according to the terrain has been used. The only way to reduce the computational load is to ignore the shadows that sink into the ground. For this reason, it was difficult to display a natural shadow.

  In view of the above inconveniences, a first object of the present invention is to provide an image display that enables a natural transition of display without reducing the sense of presence when a character enters and exits an object.

  A second problem of the present invention is to provide an image display that can display a form such as a tree with a natural texture even when an object such as a tree is displayed large.

  The third object of the present invention is to provide an image display that can display a natural shadow without increasing the calculation load and without reducing the sense of reality.

  A fourth object of the present invention is to provide a game apparatus capable of image processing according to the present invention.

  A fifth object of the present invention is to provide a recording medium capable of providing a program capable of image processing according to the present invention.

  An invention for solving the first problem is an image processing apparatus configured to be able to display one or more objects arranged in a virtual space and a character set so as to be movable relative to the object, or the same In the method, when the character reaches a predetermined condition with respect to the object, at least some of the display elements constituting the object arranged in an area associated with the movement of the character The display density can be gradually changed.

  The “object” is a display object, and here, for example, refers to a relationship between an object representing a character and an object representing a building where the character enters and exits. However, the present invention can be applied to anything in which one object falls within the other object. The “predetermined condition” is, for example, that the character enters and exits the object. It may be determined that the distance between the two objects has reached a certain value, or may be indirectly determined in a state set by the progress of the game such as “door opened” or “window opened”. The “related area” refers to an area that should be set so that an object that has entered inside can be seen by changing the display density, or an area that needs to be displayed as the game progresses. For example, in the case of a building, one united area such as the first floor part or the second floor part corresponds to that. The “at least some specific display elements” can be arbitrarily set. For example, among the display elements constituting the object, the display elements are located on the viewpoint side set in the virtual space in order to generate a display image. Since it is “at least part”, the transparency of the entire building may be adjusted or the transparency of the specific part may be adjusted. As a specific change method, for example, the display density of the specific display element is gradually decreased when the character enters the object, and is increased when the character exits.

  Here, it is preferable to set a thickness in advance for the partition member constituting the object. At this time, predetermined texture data is mapped and displayed on the cross section of the partition member displayed by a display element other than the specific display element.

  The invention for solving the second problem is an image processing apparatus or method thereof configured to display an object arranged in a three-dimensional virtual space, wherein a planar display element to which predetermined texture data is mapped is provided. An object is configured by arranging radially around a predetermined center axis so as to form a certain angle with the center axis, and one or more such objects are stacked in the vertical direction (vertical direction set in the virtual space) to overlap the virtual space By arranging in, it is configured to be able to display an image simulating a tree-like form.

  Here, the “center axis” is a portion corresponding to, for example, a “trunk”. The overall arrangement is conical or umbrella-shaped. Similarly, the display element does not need to be inclined outward, and may open upward in the coordinates of the virtual space, or the opening angle may be random. The “dendritic form” is applicable to any form other than a tree, such as a form that is not clearly defined in the natural world, such as flames, smoke, and clouds.

  Here, an object that covers at least the uppermost end of the plurality of objects is configured in a substantially umbrella shape. However, since the lower object cannot be seen near the central axis, the texture data does not necessarily have to be mapped near the central axis.

  Further, adjustment is made so that display elements mapped with the same texture data do not overlap between a plurality of adjacent objects. To prevent display elements from overlapping, it can be handled by changing the orientation of each object (the angle of the object around the central axis) for each object, or changing the order of the display elements that make up the object for each object. . Further, it may be set such that the plane of each display element protrudes to the outer peripheral side. Further, the planes of the display elements constituting the objects may be arranged in steps so as not to contact each other. Moreover, you may arrange so that the plane of a display element may make a zigzag shape in a fan shape.

  Another invention for solving the second problem is an image processing apparatus configured to display an object arranged in a three-dimensional virtual space, or a method thereof, and a planar display in which predetermined texture data is mapped A plurality of elements are arranged in a specific space area to constitute one object, and the direction in which the surface of each of the plurality of display elements faces can be controlled in accordance with the viewpoint of observing the virtual space. ing.

  The “object” here is a natural object having a complicated shape such as a tree. When the “object” is a tree, it is appropriate that the “display element” is a bundle of leaves constituting the tree. The main point is that one tree is divided into blocks composed of a plurality of display elements, and control is performed so that each display element is directed substantially in the direction of the viewpoint.

  As one method of direction control, one representative point vector is set corresponding to the viewpoint for one object, and each of the plurality of display elements constituting the object faces the direction of the representative point vector. It is conceivable to control the direction of the display element.

  As another method of controlling the direction, it is conceivable to control the direction of each display element so that each normal line of the plurality of display elements faces the direction of the viewpoint.

  For example, a weighting coefficient is set at the vertex of each display element, and the texture density mapped to the display element is configured to be linearly interpolated by the weighting coefficient between the vertices, and the weighting coefficient is arranged in the virtual space of the object. By changing corresponding to the above, the density of the texture of each display element constituting the object can be controlled.

  The invention for solving the third problem is an image processing apparatus or method for displaying an object arranged in a virtual space and a shadow of the object, and a viewpoint for displaying an image and the object. The object for displaying the shadow can be generated between the two.

  Here, the relative position between the object viewed from the viewpoint and the shadow object thereof can be changed in accordance with the height of the object from the reference plane arranged in the virtual space. For example, the shadow is configured to move downward on the screen according to the height.

  The invention for solving the third problem is an image processing apparatus configured to be able to display an object arranged in a virtual space and its shadow, or the method thereof, wherein the reference plane set in the virtual space is A light source for irradiating illumination light for displaying the shadow of the object can be set for an area where the shadow of the object is displayed. For example, a black light is arranged at a position corresponding to the sun in the virtual space. Although the irradiation position is under the object, the irradiation position may be changed according to the angle of the sun or the height of the object from the reference plane.

  The invention that solves the fourth problem is a game device comprising the image processing device of the present invention.

  The invention for solving the fifth problem is a machine-readable recording medium on which program data for causing a computer to execute the image processing method of the present invention is recorded.

  Note that the recording medium is a medium in which information (mainly digital data, a program) is recorded by some physical means, and allows a processing device such as a computer or a dedicated processor to perform a predetermined function. It can be done. In short, any means may be used as long as it downloads a program to a computer and executes a predetermined function by any means. For example, flexible disk, fixed disk, magnetic tape, magneto-optical disk, CD, CD-ROM, CD-R, DVD-RAM, DVD-ROM, DVD-R, PD, MD, DCC, ROM cartridge, with battery backup A RAM memory cartridge, a flash memory cartridge, a nonvolatile RAM cartridge, and the like are included.

  This includes the case where data is transferred from the host computer via a wired or wireless communication line (public line, data dedicated line, satellite line, etc.). The so-called Internet is included in this recording medium.

  Next, preferred embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The first embodiment relates to an image display device capable of three-dimensional image display, a method thereof, a game device, and a recording medium that enable natural image expression when an object enters and exits a building or the like.

(Description of configuration)
FIG. 1 shows a block diagram of the game apparatus of the present invention. As shown in FIG. 1, the game apparatus 1 of the present invention includes a CPU block 10, a video block 11, a sound block 12, and the like.

  The CPU block 10 relates to the processing apparatus of the present invention, and includes a bus aviator 100, a CPU 101, a main memory 102, a ROM 103, and a CD-ROM drive 104.

  The bus aviator 100 is configured to be able to control data transmission and reception by allocating a bus occupation time to devices connected to each other via a bus.

  The CPU 101 is configured to be able to access the backup memory 108 via the CD-ROM drive 104, the ROM 103, the video block 11 and the sound block 12, and the input device 107. The CPU 101 executes an initial program (initial execution program) stored in the ROM 103 when the power is turned on, initializes the entire apparatus, and detects that a CD-ROM is loaded in the CD-ROM drive 104. The operating system program data stored in the ROM is transferred to the main memory 102. Thereafter, the CPU 101 operates according to the operating system, and subsequently transfers the application program data stored in the CD-ROM to the main memory 102 and executes the program. In addition, the CPU 101 can transfer image data to the graphic memory 111 and transfer sound data to the sound memory 121. The processing by the program data executed by the CPU 101 is mainly performed by the input of the operation signal from the input device 107 and the interpretation of the communication data from the communication device 130, and by the image processing and the sound block 12 to be performed by the video block 11 based thereon. It is voice processing.

  The main memory 102 mainly stores the operating system program data and application program data, and can provide a work area for storing static variables, dynamic variables, and the like. The ROM 103 is a storage area for the initial program loader.

  The CD-ROM stores program data for causing the game apparatus to execute the image processing method of the present invention, image data for image display, audio data for audio output, and the like. The CD-ROM drive 104 is detachable from the CD-ROM. When the CD-ROM is loaded, the data is output to the CPU 101 and the data can be transferred under the control of the CPU 101. Note that the recording medium is not limited to a CD-ROM, and other various recording media may be readable. In addition, you may comprise so that the data group stored in CD-ROM via the communication apparatus 130 mentioned later may be transferred to each memory. With this setting, data can be transferred from a fixed disk of a remote server.

  The input device 107 is detachably connected to the game device, and outputs an operation signal corresponding to an operation state such as an operation button of the player to the bus of the CPU block 10. The input device 107 includes a pointing device such as a mouse or a gun-type controller in addition to a joypad and a keyboard. Further, not only one input device 107 but also two or more can be connected so that a plurality of players can play a game at the same time.

  The backup memory 108 can be detachably connected to the input device 107 and is configured to be accessible from the CPU 101. This is a storage area for setting data that is transferred from the CPU 101 and includes settings such as the progress of the game occurring during the game, the results of the game, and the operation method. These setting data not only function as backup data for restarting the game from the state immediately before the power is turned off when the power is turned off, but also reflect the operation state of the other game device as it is by replacing the backup memory. It can also be the data.

  The video block 11 includes a VDP (Video Display Processor) 110, a graphic memory 111, and a video encoder 112. The graphic memory 111 stores image data read from the CD-ROM as described above. The VDP 110 reads image data necessary for image display out of image data stored in the graphic memory 111, and information necessary for image display supplied from the CPU 101, that is, command data, viewpoint position data, and light source position data. In accordance with object designation data, object position data, texture designation data, texture density data, field of view conversion matrix data, coordinate transformation (geometry calculation), texture mapping processing, display priority processing, shading processing, etc. can be executed. The processing such as coordinate conversion may be performed by the CPU 101. That is, it is only necessary to assign which processing is to be performed to which device in consideration of the computing capability of each device. The video encoder 112 is configured to be able to convert the image data generated by the VDP 110 into a predetermined television signal such as the NTSC system and output it to the monitor device 4 connected to the outside.

  The sound block 12 includes a sound processor 120, a sound memory 121, and a D / A converter 122. The sound memory 121 stores audio data read from the CD-ROM as described above. The sound processor 120 reads audio data such as waveform data stored in the sound memory 121 based on command data supplied from the CPU 101, and performs various effect processing based on a DSP (Digital Signal Processor) function, digital / analog. Conversion processing and the like are performed. The D / A converter 122 is configured to convert the audio data generated by the sound processor 120 into an analog signal and output the analog signal to the speaker 5 connected to the outside.

  The communication device 130 is, for example, a modem or a terminal adapter, is configured to be connectable to the game device 1, and can function as an adapter for connecting the game device 1 and an external line. The communication device 130 can receive data transmitted from the game supply server connected to the public line network 131 and supply the data to the bus of the CPU block 10. The public line network 131 may be a subscriber line, a dedicated line, or a wired radio.

(Description of operation)
Next, the operation of the game apparatus will be described.
In the role-playing game provided by the operation of the game device, a story is set in which a character corresponding to a hero set to be operable by the player travels through a virtual world. Objects placed in the virtual space (that is, display objects determined in advance by program data and image data) include terrain such as the ground, buildings, trees, flames, clouds, and characters that are the main characters and characters in the game. It is. In particular, the game device is intended to display an object as if it were in the natural world. Therefore, it is set so that the objects and deformations necessary for the development of the role-playing game appear as natural as possible and do not disturb the player's concentration. Hereinafter, characteristic image processing will be described.

  The image provided by the game device is projected onto a predetermined two-dimensional plane so as to appear as if a virtual space set three-dimensionally from a predetermined viewpoint is observed. The position of this viewpoint is set so as to be able to move in the virtual space with a certain positional relationship with the character roughly corresponding to the hero. Therefore, the player is provided with images that the main character traveling in the virtual world sees one after another.

  When a character corresponding to the main character enters a building during the game sequence, if the display of the building is left as it is, the state inside the building is hindered by a wall as a partition member and is not provided to the player. Conventionally, among the walls of a building, the wall on the viewpoint side is displayed in an instant and the building itself is a building without a roof from the beginning. However, in such a display, the display changes rapidly or unnaturally. In addition, since the walls that make up the building were made by mapping texture data onto a single polygon, the cross section was displayed as a single plate, which was unnatural.

  Therefore, in order to eliminate the above inconvenience, the game apparatus gradually displays the wall on the viewpoint side of the building thinly when the character enters the building. In addition, the wall of the building is given a thickness so that its cross section does not look unnatural.

  FIG. 2A shows a flowchart for explaining the main image processing, and FIG. 2B shows a subroutine processing of the image generation processing. These processes are performed every image update timing, for example, every frame period. FIGS. 3 to 7 show image display examples showing from the start to the end of the image processing.

  Game Sequence Process (Step S11): First, the CPU 101 calculates a new position at the next image display timing of the character in the virtual space based on the operation signal supplied from the input device 107. In addition to the character, if there are other objects for which movement is set, their new positions are also calculated.

  Condition determination (S12): Next, the CPU 101 determines whether or not the character is about to enter the building. Various conditions can be considered. For example, it can be determined that “the building has been entered” at the moment when the distance between the center position of the building and the center position of the character becomes a certain value or less. It is also possible to determine that the building has entered the building by performing a known collision determination between the building object and the character and determining that the object has collided. Furthermore, the condition of the action taken by the character with respect to the object inside or outside the building, such as when the stairs are fully raised, the door is opened, or the window is opened, may be used as a condition.

  FIG. 3 shows an example of image display when this condition is met (S12; YES). In FIG. 3, a building object B and a character C are displayed in a three-dimensional manner. The character C is approaching the door of the building B. If this condition is not met (S12; NO), the CPU 101 performs normal image generation processing assuming that there is no density change processing (S16).

  Density change object specification (S13): After the above condition is met, the CPU 101 specifies an object whose density is to be changed. That is, the CPU 101 determines the specific display element (polygon group) of the building whose density is decreased from the relative position between the character and the building. For example, if it is determined that the character is entering the first floor of a building, an object number indicating “the first floor of the building” is entered as a density change object in a predetermined density change mode variable (for example, stored in the upper 4 bits) ( S14). Further, the object number may be specified from the flow of the game sequence. For example, when the building is a two-story building and a character enters from the outside, it may be determined that the character enters the first floor of the building.

  Density change flag specification (S15): The CPU 101 sets a density change mode variable flag according to whether the density change is gradually reduced or increased (for example, if the value of the lower 4 bits is 1). “Decrease”, 2 “Decrease”, 0 “No change (flag zero)”). When a character enters a building, it is necessary to display the front portion of the building thinly so that the inside of the building can be easily seen. Conversely, when the character leaves the building, it is necessary to darken the texture of the front portion of the building in order to restore the building display. The CPU 101 refers to various flags indicating the game sequence state to determine the action or moving direction that the character is taking and determines the density change mode. A predetermined code for indicating the density change mode is stored in the density change mode variable together with the object number. The CPU 101 handles that the density change flag is turned on when a code is set in this variable (for example, when a value other than 0 is stored). Of course, the design of the method for assigning the concentration change code to the variable can be variously changed.

  Image generation processing (S16): When the setting of the density change mode is completed, the CPU 101 proceeds to image generation processing. Here, the normal image generation processing step is omitted, and the description will be made from the stage of mapping the texture and performing the shadediner process for the building. First, the CPU 101 refers to the density change mode variable. When the flag is off (S101; NO), that is, when the density is not changed, the CPU 101 returns with the texture density of the building unchanged.

  When the flag is on (S101; YES), that is, when the density is changed, the CPU 101 further refers to the variable code and reads the object number and density change mode for changing the density. When the mode for increasing the density is set (S102; increase), the texture mapped to the polygon group (specific display element) constituting a part on the viewpoint side of the building associated with the object number A shading process for increasing the data density by one gradation is performed (S103). The gradation that determines the density can be variously changed according to the speed at which the density is changed. When there are few gradations, the change is rapid, and when there are many gradations, the change is slow. For example, if the gradation is set to 60, the density change can be completed in 60 loop processes (about 1 second in the NTSC system). This gradation is set by a command supplied to the video block 11.

  When the density changes and becomes the darkest gradation (that is, normal opaque display) (S104; YES), the density change flag is turned off, that is, the density change mode variable is cleared to zero (S105).

  In the process of changing the concentration (S104; NO), the concentration change flag is not turned off. For example, this process is shown in order in FIGS. When the character C enters the building B, the texture density of the polygon group which is the specific display element among the polygons constituting the building B decreases. Finally, as shown in FIG. 7, the specific display element is completely invisible, and the objects O1 to O4 arranged inside the building and the character C walking in the room are displayed. As can be seen from FIG. 7, it is preferable that the objects displaying furniture and interior are not changed in density and arranged along the wall surface as far as possible from the viewpoint so that the inside can be easily observed.

  Here, in this game device, the thickness is set on the wall of the building. Traditionally, there was no wall thickness, so it was unnatural to erase part of the building. In the present invention, the polygons constituting the outer wall of the building and the polygons constituting the inner wall are respectively set, and a certain distance is set between both polygons. For this reason, as the density of the specific display element becomes lighter as described above, the display element that is determined not to change the density can be seen through, and the cross section of the outer wall and the inner wall of the building can be seen. Since it is unnatural if the texture is not mapped to this cross section, the game apparatus maps the cross-section texture data between both walls. In FIG. 7, SS1 to SS5 are visible as cross sections, texture data for the wall cross section erected on SS1 to SS3, and texture data for the floor cross section are mapped to SS4 and SS5, respectively. . Since the texture is pasted on these sections, there is no unnaturalness even if the specific display element becomes transparent, and the player can be given the illusion of looking at the actual section of the building.

  If the mode for increasing the density is set in step 102 (S102; lighten), a part of the viewpoint side of the building corresponding to the object number is configured as the reverse process to the above. A shading process is performed to decrease the density of the texture data mapped to the polygon group (specific display element) to be reduced by one gradation (S106). When the density changes and becomes the lightest gradation (ie, transparent display) (S107; YES), the density change flag is turned off, that is, the density change mode variable is cleared to zero (S105). In the process of changing the concentration (S107; NO), the concentration change flag is not turned off.

  In addition, the said process is applicable not only when entering / exiting a building but with various changes. For example, when there are a plurality of rooms in a building, an object number is set for each room, and it is possible to control whether the room is darker or thicker. In other words, when a character moves from one room to another, the density of the room that has passed through is gradually returned to the original condition, assuming that it has come to the boundary of the room, and the room to enter It is possible to gradually reduce the concentration.

  In the case of a two-story building as shown in FIGS. 3 to 7, the specific display element set on the first floor is subject to the condition that the character is climbing the stairs (O2 in FIG. 7). It is only necessary to restore the density and lower the density of the specific display element set separately for the second floor. When going down the stairs, do the reverse. According to such processing, the wall surface can be naturally erased and reproduced as the character progresses, so there is no risk of reducing the player's concentration.

  According to the present embodiment, when a character enters and exits an object such as a building, it is possible to change the natural display without reducing the presence of a player who is immersed in the game world.

(Embodiment 2)
The present embodiment relates to a method that enables expression of objects such as trees with a rich presence without displaying an unnatural image on a game device having a certain limitation in processing capability.

  Since the hardware used in the second embodiment is as shown in the first embodiment, the description thereof is omitted. However, it is assumed that polygon data, texture data, and the like for enabling expression of the tree of the present invention are read from the CD-ROM into the game device. The operation will be described below.

  In the virtual world, when a character corresponding to the hero approaches an object (such as a tree), the object is enlarged and displayed as in the case of actually approaching the tree.

  In the conventional tree display method, the texture of the entire tree is expressed on a single plane polygon, or the polygon mapped with the texture for expressing the leaves is combined as if inserted into a cross in the center of the trunk, For example, trees are represented by ball-like objects, and texture data is mapped on the polygons to make them look like trees. For this reason, when the viewpoint approaches a tree, leaves are displayed in a plate shape, and the expression is not like a tree.

  On the other hand, in this game apparatus, a planar display element (polygon) to which texture data is mapped is configured as an object (for example, an umbrella shape) arranged radially around the central axis so as to form a certain angle with the central axis. . By placing one or more umbrella-shaped objects in the virtual space, it is possible to provide a tree-like image even when approaching.

  FIG. 8 shows one umbrella-like object represented by a wire frame among the tree objects provided by the game apparatus. FIG. 8A is a perspective view thereof, and FIG. 8B is a plan view thereof. In this figure, eight triangular polygons are used to form an umbrella-like object in an octagon, but the number and shape of polygons are not limited to this. By mapping texture data consisting of spots with slightly different densities and color tones to each of these polygons, a tree-like expression becomes possible. If all polygons are faced down, that is, an umbrella shape, the texture of coniferous trees such as cedar can be given, and if the polygons are oriented upward or downward or randomly placed, the texture of hardwood can be given. .

  FIG. 9 is an explanatory diagram of a tree object using five (C1 to C5) umbrella-shaped objects. The tree object is configured by placing umbrella-like objects C1 to C5 around a trunk object T surrounding the central axis A. The angles θ1 to θ5 formed by the polygons forming the umbrella-like objects C1 to C5 and the central axis A may be the same as or different from each other. The same applies to the radii r1 to r5 of the umbrella-shaped object and the pitches p12, p23, p34 and p45 between the umbrella-shaped objects. A more realistic image can be displayed by increasing the number of umbrella-shaped objects or decreasing the pitch p, but the amount of data and the processing time increase. Therefore, these are determined according to the memory capacity and processing capacity.

  A specific image generation procedure is shown in FIG. In the above-described image generation process (FIG. 2A: step S16), in parallel with image generation of other objects, the CPU 101 first specifies polygons and determines polygon data groups for displaying the objects (S1). . This specifies the polygon to be used. Next, the CPU 101 transfers object designation data indicating matrix data for determining the specified polygon and its size to the video block 11. This determines the individual shape of the object to be used (S2). Further, the CPU 101 transfers object position data for determining the spatial arrangement of the umbrella-shaped object and the trunk object to the video block. This determines the shape of the trees other than the texture (S3). Finally, texture designation data for designating texture data to be mapped to the polygons constituting the umbrella object or the trunk object is transferred. In the video block 11, the texture data is mapped to complete a tree object. The field of view of this object is converted and an image is displayed (S4).

  Note that the umbrella-shaped object can be variously changed. For example, as shown in FIG. 11, when the arrangement of the textures T1 to T8 to be arranged on the umbrella-shaped object is set in common to all the umbrella-shaped objects, the texture data is sequentially added to the umbrella-shaped objects C1, C2, C3,. It is possible to shift the mapping position. In this way, the same texture data is not overlapped by the upper and lower umbrellas while mapping the same texture data to the umbrella-like object, and a natural tree texture can be provided.

  Also, as shown in FIG. 12, it is easy to increase the diameter of the umbrella by shifting the polygon to the outer peripheral side for other umbrella-like objects C2 to C5 other than the uppermost umbrella-like object C1. Can be. The calculation time can be reduced in that it is not necessary to change the size of the polygon.

  Further, as shown in FIG. 13, it is possible to arrange the polygons constituting the umbrella-like object so as to be shifted vertically without contacting each other. In this way, the leaves of the trees overlap in multiple layers, and it becomes possible to provide a more natural tree texture. Further, the object may be arranged in a fan shape so that the cross section is zigzag.

  Although the description of the present embodiment is related to the representation of trees, objects to which the present invention can be applied are not limited to trees. Because it has a complicated shape, the number of processes can be enormous to reproduce faithfully, but it can be applied to any object that may appear unnatural when approaching with a simple texture expression. It is.

  According to the second embodiment, even if a character approaches an object such as a tree, the tree can be displayed with a natural texture, and the player's sense of reality is not lost.

(Embodiment 3)
The present embodiment relates to another method that enables the expression of trees with a rich sense of reality as in the second embodiment.

  Since the hardware used in the third embodiment is as shown in the first embodiment, the description thereof is omitted. However, it is assumed that a program, polygon data, texture data, and the like for enabling expression of the tree of the present invention are read from the CD-ROM into the game device. The operation will be described below.

  In the second embodiment, the shape of a display element representing a bundle of leaves is drawn in a special shape to represent a tree object, whereas in the third embodiment, texture data representing a bundle of leaves is drawn. A plurality of planar display elements that are mapped to each other are arranged in a specific space area around the trunk to constitute one object.

  FIG. 14 shows a perspective view of the tree object of the present embodiment expressed as a wire frame. As shown in FIG. 14, the tree object is composed of a display element T representing a trunk and a plurality of display elements P representing a bundle of leaves.

  The display element T expressing the trunk is configured in a space shape of the trunk by a plurality of polygons. Each of the display elements P representing a bundle of leaves is composed of a single polygon composed of a predetermined number (for example, four) of vertices. The display element P is arranged with appropriate variation in a space region around the display element T representing the trunk. The arrangement of the display elements P is determined in advance so that the overlapping of the display elements P is reduced when viewed from the position of the virtual space where the viewpoint mainly exists. Such image data of the tree object is stored in advance on a CD-ROM or the like.

  FIG. 15 is an explanatory diagram of the direction control method in the present embodiment.

  In the direction control of the present embodiment, as shown in FIG. 15, one representative point vector V1 is set for each tree object corresponding to the viewpoint VP, and a plurality of display elements P constituting this object are represented as representative points. The direction of each display element P is controlled so as to face the direction of the vector V1. That is, the direction in which the surface of each of the plurality of display elements faces is unified and dynamically changed corresponding to the direction VO of the viewpoint VP, and is controlled to always face the same direction.

  The representative point vector V1 is determined at an arbitrary point on the tree object. An arbitrary point may not be set on the display element P or T, but is set on a specific display element P0 here. Since the direction of the other display element P also faces in the direction in which the specific display element P0 faces, it is preferable that the display element P near the center of the tree object be the specific display element P0.

  The representative point vector V1 is preferably set in the same direction as the line-of-sight vector V0, that is, in the Z-axis direction for visual field conversion. In this way, the specific display element P always faces the viewpoint VP, and the other display elements P also generally face the viewpoint VP.

  FIG. 16 shows an enlarged view of the display element P expressing a bundle of leaves. The display element P has a square shape, for example, and is defined by the coordinates of the vertices VX1 to VX4. The number of vertices is not limited, but it is sufficient to provide 3 to 4 points. Each display element P is arbitrarily rotatable around three rotation axes X, Y, and Z that intersect at the center point (center of gravity). Specifically, when the display element P defined in the body coordinate system is expanded in the world coordinate system, the display element P is rotated and arranged at each rotation angle of the determined XYZ axes. In this way, each display element P is configured to be able to direct its normal direction in an arbitrary direction, so that the direction of the display element P can always be controlled according to the viewpoint position.

  In each display element P, the same texture data PT is mapped. A plurality of types of texture data may be provided if there is room in the memory, but a single type is sufficient because sufficient texture can be expressed by linear interpolation of luminance (density). However, even when the same texture data is used, it is preferable to randomly change the mapping direction for each display element P. By adopting such a method, the shape of the leaf bundle is displayed differently, so that it is possible to express a very natural tree even though texture data having the same shape is used.

  Each vertex constituting the display element P is set with a weighting coefficient for defining primary interpolation of luminance. The setting of the value is arbitrary. For example, if it is defined in the range of 0 to 1, the luminance is zero (that is, black on display) when it is 0, and the luminance is 100% (that is, white on display) when it is 1. When mapping a texture to one display element P, the processing device is configured such that the luminance of the texture mapped to the display element P can be linearly interpolated by the weighting coefficient of each vertex. For example, if the weighting factor 1 is set at one vertex on the display element and the weighting factor 0 is set at the other vertex, the brightness from one vertex to the other vertex is increased from light to dark between the two vertices. The texture is displayed with a gradient that gradually falls.

  FIG. 17A shows an example of texture mapping when all vertex weighting coefficients are set to 1, and FIG. 17B shows an example of texture mapping when vertex weighting coefficients are changed on opposite sides. . When the same weighting coefficient is set for all the vertices, as shown in FIG. 17A, a flat display with no difference in brightness is obtained. On the other hand, when the weighting coefficient of the vertices is changed, a difference in brightness appears as if sunlight is radiated from one direction, resulting in a stereoscopic effect.

  Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

  When it is necessary to display a tree object in a virtual space, the CPU 101 generates a display element of a trunk by using a polygon group associated with the display element T in order to generate a display element T for expressing the trunk read from the CD-ROM. To do. Then, the center (center of gravity) position of each display element P is set around the trunk display element T (S21). After reading the polygon of the display element P, the CPU 101 arranges the polygon of the display element P at the center position of the previously set display element P (S22).

  After obtaining the viewpoint vector V0 from the viewpoint VP (S23), the CPU 101 calculates the representative point vector V1 (S24). As the representative point vector V1, the viewpoint vector V0 directed to the specific display element P0 on the tree object may be used as it is.

  In order to set the density of texture mapping, the CPU 101 reads the ambient light vector (S25) and recognizes the main illumination direction for the tree object. A weighting coefficient to be set at the apex of each display element P is determined in correspondence with the recognized environmental light vector (S26). It is set so that the weighting coefficient of the vertex near the direction of the ambient light is high and the weighting coefficient of the vertex far away is low. Since the density (brightness) setting is not strict, the weighting coefficient of the vertex closest to the ambient light is 1, the weighting coefficient of the farthest vertex is 0, and the weighting coefficient of the middle vertex is 0.5. Can be assigned. However, the weighting coefficient may be determined by performing linear calculation based on the intensity of the ambient light and the positional relationship between the ambient light and each vertex. A different weighting factor may be set for each display element P. However, since ambient light affects the entire tree object equally, the weighting factor determined for one display element P is assigned to all other display elements P. It is sufficient to set similarly.

  The CPU 101 directs the direction of the polygon to the direction of the representative point vector V1 previously determined for each display element P arranged on the tree object (S27). For the display element P whose direction is controlled, the CPU 101 maps the texture data PT (S28). At this time, the luminance of the texture is linearly interpolated according to the weighting coefficient of the vertex defined above, and the bitmap data is created so as to generate the shading (brightness / darkness).

  The CPU 101 performs direction control (S27) and texture mapping (S28) as long as there is a polygon that is the display element P (S29: NO). When the direction control and texture mapping of all the polygons are completed (S29: YES), the CPU 101 proceeds to the next process.

(Example)
An example when a tree object is actually drawn according to the present embodiment will be described. FIG. 19 shows a wire frame representation when the arrangement of tree objects is determined from the side. Display elements P that express a bundle of leaves are arranged apart from each other around a display element T that expresses a trunk. In this embodiment, 44 display elements P are arranged.

  FIG. 20 shows a display example in which texture data is mapped to the tree object defined in FIG. In this example, the weighting coefficient of each display element P is set on the assumption that ambient light is shining from above the drawing (see FIG. 17B). The background image BG is displayed through the portion of the texture data mapped to the display element P where there is no data. A shadow object S is displayed below the tree object. This shadow is as displayed in an embodiment described later.

  FIG. 21 is a wire frame representation when the viewpoint position is moved to the upper part of the tree object. FIG. 22 shows a mapper of texture data.

  According to the present embodiment, although the texture data mapped to each display element P is the same, the texture like a natural tree is sufficiently expressed by the shading by the weighting coefficient and the random arrangement. Can be confirmed.

  FIG. 23 shows a case where a uniform weighting coefficient is set for comparison, that is, a case equivalent to the case where there is no primary interpolation. Without linear interpolation, there will be no shading or contrast, resulting in a planar image representation.

  FIG. 24 is an image display example when weighting is performed assuming that the direction of the ambient light is on the lower side (ground side). It can be confirmed that a realistic image display can be performed even when a supernatural image such as the ground is shining.

(Modification)
In the above embodiment, one representative point vector V1 is defined and the direction of all the display elements P is directed to that direction. Then, the direction may be controlled so as to be directed toward the viewpoint VP. That is, as shown in FIG. 25, the direction of each display element P is controlled such that each of the normal lines V3 of the plurality of display elements P faces the direction of the viewpoint VP. A specific display element P is not determined, and the direction of all the display elements P is controlled so that the normal to the center of gravity PC is parallel to the line-of-sight vector V0.

  By performing such processing, the texture of the leaves is naturally expressed in any part of the tree, even when the viewpoint is extremely close to the tree object (for example, the viewpoint of an insect staying on the trunk). It becomes possible.

  Although the description of the present embodiment is related to the representation of trees, objects to which the present invention can be applied are not limited to trees. Because it has a complicated shape, the number of processes can be enormous to reproduce faithfully, but it can be applied to any object that may appear unnatural when approaching with a simple texture expression. It is.

  As described above, according to the third embodiment, even if the viewpoint is extremely close to an object such as a tree, the tree can be displayed with a natural texture, and the player's sense of reality is not cut. Play.

(Embodiment 4)
The present embodiment relates to a method capable of expressing a natural shadow that does not reduce the sense of presence in a game device having a certain limitation in processing capability.

  Since the hardware used in the fourth embodiment is as described in the first embodiment, the description thereof is omitted. However, it is assumed that a program for enabling the expression of the shadow of the present invention, image data, and the like are read into the game device from the CD-ROM. The operation will be described below.

  When a shadow is added to a character in a conventional game device, a black object indicating the shadow is placed under the character. However, inconvenience arises when unevenness is given to the ground to make it look like a natural land shape. In other words, when the character moves on the uneven ground, the shadow object is displayed in the protruding portion of the ground.

  This embodiment proposes a simple and effective method for applying a shadow. The method is an image processing method for generating an object for displaying a shadow between a viewpoint and a character.

  The image processing method of this embodiment will be described with reference to the flowchart of FIG. This flowchart shows a processing method for generating an image of one object.

  First, the CPU 101 performs normal game sequence processing, and determines the position of an object in a new image update period (S31). For example, as shown in FIG. 27, in the virtual space, the ground G, which is the reference plane, and the character C are composed of polygons, and the arrangement of the character C and the ground G is determined. Next, in order to generate a shadow object, it is determined whether or not the object arranged in the virtual space is a character (S32). If it is not a character (S32; NO), that is, if it is an object simulating a still life that does not need to be shaded, the process proceeds to image generation processing without a shadow as it is (S35).

  If the object is a character (S32; YES), the height of the character is calculated (S33). The height of the character is determined based on the position of the character center CC set below the character X as shown in FIG. In FIG. 27, since the character C is walking on the ground G, the height is zero. In FIG. 28, since the character C is at the jump position, the height is H.

  Next, the shadow position is determined according to the height of the character. For example, as shown in FIG. 27, when the height is zero, the CPU 101 sets the center SG of the object of the shadow S so as to be positioned on the line connecting the viewpoint VP and the character center CC. For example, the shadow center SC is arranged on a sphere SP having a constant radius Rs from the character center CC. Therefore, when the viewpoint VP moves, the position of the shadow center SC also moves along the surface of the sphere SP. FIG. 29 shows a schematic diagram of image display by this arrangement, and FIG. 31 shows an image display example. Since the shadow S is in front of the character C, the shadow S is displayed so as to be applied to the feet of the character C. However, since only a part of the feet is applied, there is no unnaturalness. If the viewpoint VP is moved to the same position as the ground G, the shadow S becomes invisible because the plane of the shadow S and the line of sight become parallel.

  If the height of the character C is not zero, the shadow is moved downward in the virtual space according to the height. More specifically, it is moved along the intersection line between the surface perpendicular to the ground G including the line connecting the viewpoint VP and the character center CC and the surface of the sphere SP. The moving distance is proportional to the distance, for example. For example, in FIG. 28, since the height is H, the shadow center SC moves on the sphere SP in the direction of the white arrow. FIG. 30 shows a schematic diagram of image display by this arrangement. A natural image in which the character C jumps off the ground and the shadow S is displayed away is displayed.

  When the positional relationship between the character and its shadow is determined as described above, the CPU 101 performs normal image generation processing and maps texture data to the character and shadow (S35). For example, as shown in FIG. 31, the shadow S object is mapped with black data whose peripheral portion is blurred.

  According to the present embodiment, it is possible to display a natural shadow without increasing the calculation load, and there is an effect that the player's sense of realism is not lost.

(Embodiment 5)
This embodiment relates to another method that enables natural shadow expression in the fourth embodiment.

  Since the hardware used in the fifth embodiment is the same as that shown in the first embodiment, the description thereof is omitted. However, it is assumed that a program for enabling the expression of the shadow of the present invention, image data, and the like are read into the game device from the CD-ROM. The operation will be described below.

  In this embodiment, another method for providing a simple and effective shadow is proposed. That method is a method of setting illumination light for displaying a shadow in a region where the shadow of the character is displayed, that is, a light source for irradiating black light.

  In order to carry out the image processing method, the CPU 101 sets a light source (black light) that emits dark illumination downward on the character C corresponding to be shaded. For example, as shown in FIG. 33, the black light source LP is set above the character C. For example, the character center CC and the light source LP are arranged on the vertical line of the ground G. However, in order to express that the sun is tilted, the position of the light source LP may be moved to a position corresponding to the direction of the sun at that time. Based on the above settings, the CPU 101 performs rendering processing (shading processing) based on the light source LP. At that time, the CPU 101 performs rendering processing by reflecting the light source LP only on the polygons constituting the ground G.

  As described above, as shown in FIG. 33, only the ground G in the area irradiated with the black light from the light source LP is displayed darkly, and this is displayed as a shadow S. The shadow center SC is located on a line connecting the light source LP and the character center CC. FIG. 34 shows an actual image display example. Since the shadow S is displayed so as to be reflected only on the ground G, the feet of the character C do not become dark. Note that, by moving the position of the light source according to the height of the character, the position of the shadow can be changed corresponding to the height as in the method of the fourth embodiment.

  According to the fifth embodiment, it is possible to display a natural shadow without increasing the calculation load, and there is an effect that the player's sense of reality is not lost.

(Other variations)
The present invention can be modified in various ways regardless of the above embodiments. For example, in the above embodiment, all display elements and objects are configured by polygons, but objects may be displayed by other methods regardless of polygons.

  In the first embodiment, the density is sequentially changed when the character enters and exits the building. However, the present invention is not limited to the relationship between the character and the building. The invention can be applied. The present invention can also be applied when making a part of an object transparent regardless of the entry and exit of a character.

  Furthermore, in the second and third embodiments, the present invention is applied to an object such as a tree. However, the present invention is provided when displaying an object simulating a natural form of a messy feeling like a tree. Is possible. For example, it is effective for expressing a material whose shape is not clear, such as hair or flame, with a rich texture.

  Furthermore, in the first, fourth, and fifth embodiments, the character is a person. However, the model is not limited to a person, and the present invention can be applied to animals, robots, and further moving objects such as cars and airplanes.

  ADVANTAGE OF THE INVENTION According to this invention, when a character goes in and out of an object, the image display which enables the transition of a natural display without reducing a sense of reality can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, even if it displays large, when displaying objects, such as a tree, the image display which can display a tree with a natural texture can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the image display which can display the natural shadow which does not increase the calculation load and does not reduce a sense of reality can be provided.

  According to the present invention, it is possible to provide a game device capable of the image processing.

  According to the present invention, it is possible to provide a recording medium capable of providing a program capable of the image processing.

The block diagram of this game device. 6 is a flowchart for explaining density change processing according to the first embodiment, which is a condition match determination process. 5 is a flowchart for explaining density change processing according to the first embodiment, and details of image generation processing; An image display example showing a change in density change (first stage). An image display example showing the transition of density change (second stage). An image display example showing the transition of density change (third stage). An image display example showing the transition of density change (fourth stage). An image display example showing a change in density change (fifth stage). An example object (perspective view) representing a tree in a wire frame representation. An example object (plan view) representing a tree in a wire frame representation. FIG. 6 is a configuration diagram of a tree object in the second embodiment. Explanatory drawing of the procedure which produces | generates the image of the object of a tree. Modified example (1) of an umbrella-shaped object. Modified example (part 2) of the umbrella-shaped object. Modified example (3) of the umbrella-shaped object. The block diagram of the tree object in Embodiment 3. FIG. Explanatory drawing of direction control of each display element (polygon) in Embodiment 3. FIG. FIG. 6 is a control explanatory diagram of one display element (polygon). The texture display figure at the time of setting the same weighting coefficient to each vertex of a display element. The texture display figure at the time of setting the same weighting coefficient to each vertex of a display element. 10 is a flowchart for explaining direction control of a tree object according to the third embodiment. The wire frame block diagram (side view) of the direction-controlled tree object. The example of a display (side view) which mapped the texture to the tree object by which direction control was carried out. The wire frame block diagram (bottom view) of the direction-controlled tree object. A display example (plan view) in which a texture is mapped to a direction-controlled tree object. The example of a tree object display when not controlling the weighting coefficient of each display element. The example of a tree object display when the weighting coefficient of each display element is changed. Explanatory drawing of direction control of each display element by the other method in Embodiment 3. FIG. 10 is a flowchart for explaining shadow generation processing according to the fourth embodiment. Arrangement explanatory drawing of the state where the character is contacting the ground. Arrangement explanatory drawing of the state where the character is jumping. The schematic diagram of the image display in arrangement | positioning of FIG. The schematic diagram of the image display in arrangement | positioning of FIG. The example of an image display in Embodiment 4 (viewpoint diagonally upward). The example of an image display in Embodiment 4 (on a viewpoint ground). Arrangement explanatory drawing in Embodiment 5. FIG. 10 is an image display example according to the fifth embodiment.

Claims (5)

In an image processing apparatus configured to be able to display one or more objects arranged in a virtual space and a character set to be movable relative to the objects,
When the character enters and exits the object, the display density of at least some of the specific display elements among the display elements that are arranged in the area associated with the movement of the character is gradually changed. Equipped with a processing device capable of
The specific display element for changing the display density is a display element located on the viewpoint side set in the virtual space for generating a display image among the display elements constituting the object,
The image processing apparatus, wherein the processing apparatus gradually decreases the display density of the specific display element when the character enters the object and increases the density when the character exits. The partition member constituting the object has a thickness set in advance,
The processing device is configured to map and display predetermined texture data on a cross section of the partition member displayed by a display element other than the specific display element.
The image processing apparatus according to claim 1. In an image processing method for displaying one or more objects arranged in a virtual space and a character set to be movable relative to the object,
Determining whether or not the character has reached a predetermined condition with respect to the object, wherein the predetermined condition is that the character enters and exits the object; and
The step of gradually changing the display density of at least some of the specific display elements among the display elements constituting the object arranged in the area associated with the movement of the character when the predetermined condition is reached. The display density of the specific display element gradually decreases when the character enters the object, and increases when the character exits;
Comprising
Image processing method. The step of setting a thickness in advance on the partition member constituting the object and mapping and displaying predetermined texture data on a cross section of the partition member displayed on a display element other than the specific display element,
The image processing method according to claim 3.   A machine-readable recording medium on which program data for causing a computer to execute the image processing method according to claim 3 or 4 is recorded.