JP3715568B2 - Image drawing apparatus, recording medium, and program - Google Patents

Description

[0001]
The present invention is suitable for drawing a large number of objects having the same shape, such as plant leaves. Painting The present invention relates to an image drawing apparatus, a recording medium on which a program for realizing the image drawing process is recorded, and a program.
[0002]
[Prior art]
Recently, computer graphics (CG) processing such as hidden line processing, hidden surface removal processing, smooth shading, texture mapping, and the like has rapidly progressed in conjunction with the rapid development of hardware.
[0003]
As CG processing, in general, a plurality of three-dimensional shapes (objects) are created by CAD three-dimensional modeling, and colors and shadows are given to these objects, and optical properties such as specular reflection, diffuse reflection, refraction, and transparency are applied. A rendering process is performed in which a special characteristic is added, a surface pattern is added, and drawing is performed in accordance with surrounding conditions (such as reflection of a window or a scene, or a reflection of light).
[0004]
[Problems to be solved by the invention]
By the way, when drawing a lot of objects of the same shape, such as plant leaves, a method of drawing by applying the above-described rendering processing to all the objects can be considered, but the processing is performed in units of fine polygons, so that It takes a long time to calculate and draw, and for example, the display speed of these objects on the monitor screen is slow.
[0005]
In addition, when each leaf is displayed as a single polygon, the display may be unnatural depending on the position of the viewpoint because the polygon is a plane.
[0006]
If each leaf is composed of a plurality of polygons, it can be approximated to a shape having a gentle curved surface like a real leaf, but the polygon information data will be enlarged.
[0007]
Furthermore, when producing an image having a large number of polygons such as plant leaves, the image producer must determine the arrangement of the large number of polygons one by one, which is a heavy burden on the image producer. Yes.
[0008]
The present invention has been made in consideration of such problems, and when drawing a large number of components having the same shape, such as plant leaves, each component is represented by a single polygon. By rotating the polygon so that it faces the correct direction, the time required for calculation and drawing can be greatly reduced. Painting An object of the present invention is to provide an image drawing apparatus, a recording medium on which a program capable of realizing the image drawing process is recorded, and a program.
[0009]
[Means for Solving the Problems]
Image drawing apparatus according to the present invention, recording medium according to the present invention, and program according to the present invention Is In a coordinate system in a virtual space where objects and polygons are arranged, at least one polygon is rotated by a predetermined means. means And the direction of the reference virtual viewpoint for drawing the image and the direction of the normal direction of the surface of the rotated polygon are 90 ° ± a °, the orientation of the polygon surface is reset. means It is characterized by having.
[0010]
By doing so, the polygon is not difficult to see from the virtual viewpoint, and the natural atmosphere of the plant can be expressed. Here, if the polygon is an image including leaves or branches of a plant, the plant can be drawn.
[0011]
Ma The predetermined means may be a random number generation means, and the polygon may be rotated in a direction set from the random number obtained by the random number generation means.
[0013]
By doing so, the polygon is not difficult to see from the virtual viewpoint, and the natural atmosphere of the plant can be expressed.
[0019]
Furthermore, it is easy to process the said polygon if it is a rectangle or a square.
[0020]
Furthermore, the amount of data related to the polygon can be reduced by having position information data of at least one vertex among all the vertices of the polygon.
[0021]
In the step of rotating the polygon, a rotation calculation is performed on the position information data of the at least one vertex to obtain a converted position after the rotation, and the other vertex is calculated from the converted position. Can be reduced.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention relates to Painting An embodiment in which an image drawing apparatus is applied to an entertainment system, and an embodiment in which a recording medium and a program according to the present invention are applied to a recording medium and a program on which a program and data executed by the entertainment system are recorded This will be described with reference to FIGS.
[0023]
First, as shown in FIG. 1, an entertainment system 10 according to the present embodiment basically includes an entertainment device 12 that executes various programs, and a memory card 14 that is detachable from the entertainment device 12. And an operation device (controller) 16 that is detachable from the entertainment device 12 and a monitor (display) 18 that is a display device such as a television receiver to which video / audio signals from the entertainment device 12 are supplied. Composed.
[0024]
The entertainment device 12 reads out a program recorded on a large-capacity storage medium such as an optical disc 20 such as a CD-ROM or DVD-ROM, and responds to an instruction from a user (for example, a user or a game player). This is for executing a game or the like. The execution of the game mainly means that the input from the controller 16 is received through the connector 15 and the progress of the game is controlled while controlling the display and sound on the screen of the monitor 18.
[0025]
As shown in FIG. 1, the entertainment device 12 has a shape in which flat rectangular parallelepipeds are stacked, and the front panel is a disc mounting portion on which an optical disc 20 serving as a program / data recording medium is mounted. A disk tray 22 that moves back and forth, a reset switch 24 for arbitrarily resetting a program currently being executed, an open button 26 for pulling out the disk tray 22, and two insertion ports 30 of the memory card 14 And two controller terminals 32 and the like into which the connector 15 of the controller 16 is inserted. On the back side, there are a power switch 28, video and audio output terminals, and a monitor 18 via an AV (audio visual) cable. An AV multi-output terminal (not shown) connected to is arranged.
[0026]
The entertainment device 12 reads the program from the optical disc 20 which is a recording medium such as a CD-ROM or DVD-ROM in which a computer game (video game) program and data are recorded, and executes the program to thereby display the screen of the monitor 18. In addition to the control function for displaying characters and scenes above, various control functions such as movie playback using a DVD (digital video disk), which is another optical disc 20, and music playback using a CDDA (compact disk digital audio) are incorporated. Yes. It also has a function of executing a program obtained by communication via a communication network or the like. During the execution of the game program, the three-dimensional computer graphics image generated by the entertainment device 12 is displayed on the screen of the monitor 18 as a display device.
[0027]
In this case, the signal from the controller 16 is also processed by one of the control functions of the entertainment device 12, and the contents are reflected on the screen of the monitor 18, for example, on the movement of the character, switching of the scene, and the like. ing.
[0028]
The controller 16 is provided with first and second operation units 51 and 52 on the center left and right of the upper surface, third and fourth operation units 53 and 54 on the side surface, and analog operation on the front left and right of the upper surface. A left joystick 70 and a right joystick 72 for performing the above are provided.
[0029]
The first operation unit 51 is a pressing operation unit for giving an action to a character or the like displayed on the screen of the monitor 18, for example. The function is set by a program or the like recorded on the optical disc 20, and the character or the like is selected. It is composed of four operation keys (also referred to as direction keys) 51a, 51b, 51c, 51d having a function of moving up, down, left and right. The direction key 51a is also referred to as an up key, the direction key 51b as a down key, the direction key 51c as a left key, and the direction key 51d as a right key.
[0030]
The second operation unit 52 has four operation buttons 52a, 52b, 52c, and 52d in a columnar shape for pressing operation, and “△” and “ The identification marks “O”, “X”, and “□” are attached, and the operation buttons 52a to 52d are also referred to as a Δ button 52a, a ○ button 52b, an X button 52c, and a □ button 52d, respectively.
[0031]
The functions of the operation buttons 52a to 52d of the second operation unit 52 are set by a program or the like recorded on the optical disc 20. The operation buttons 52a to 52d have, for example, a left arm, a right arm, a left foot, and a right foot such as a character. The function to move is assigned.
[0032]
The third and fourth operation units 53 and 54 have substantially the same structure, and both of them are two operation buttons (also referred to as L1 buttons) 53a for pressing operation that are lined up and down, and are also referred to as operation buttons (L2 buttons). ) 53b, operation buttons (also referred to as R1 buttons) 54a, and operation buttons (also referred to as R2 buttons) 54b. The functions of the third and fourth operation units 53 and 54 are also set by a program recorded on the optical disc 20, and for example, a function for causing a character to perform a special action is assigned.
[0033]
The left and right joysticks 70 and 72 are each provided with a signal input element such as a variable resistor that can be tilted and rotated in the direction of 360 ° around the operation axis, and an analog value is output according to the tilt and rotation. . The left and right joysticks 70 and 72 are returned to the neutral position by an elastic member (not shown). When the left and right joysticks 70 and 72 are pressed downward, signals different from the analog values associated with the tilting and rotation of the joysticks 70 and 72 are output. That is, the left and right joysticks 70 and 72 have the functions of operation buttons (L3 button) 70a and (R3 button) 72a as fifth and sixth operation units for pressing operation.
[0034]
By rotating and tilting the left and right joysticks 70 and 72, for example, moving the character or the like while rotating it, or moving it while changing the speed, and further performing an analog movement such as changing the state. It becomes possible to input a command signal to be enabled.
[0035]
In FIG. 1, the left and right joysticks 70 and 72 can be used by switching to the first and second operation units 51 and 52. The switching is performed by an analog mode switch 74. When the left and right joysticks 70 and 72 are selected by the analog mode switch 74, the display unit 76 is turned on, and the selection state of the left and right joysticks 70 and 72 is displayed.
[0036]
As shown in FIG. 3, analog input values obtained by operating the left and right joysticks 70 and 72 are “0” to “255” in the vertical direction from top to bottom, and from left to right in the horizontal direction. “0” to “255”.
[0037]
In addition to the above, the controller 16 is provided with a start button (start switch) 78 for instructing the start of a game and the like, a select button (selection switch) 80 for selecting a difficulty level of the game at the start of the game, and the like. Yes.
[0038]
Next, the internal configuration and general operation of the entertainment apparatus 12 shown in FIG. 1 will be described with reference to the block diagram of FIG.
[0039]
The entertainment apparatus 12 is configured by connecting a RAM 402 and a bus 403 as semiconductor memories to a CPU 401 that controls the entertainment apparatus 12.
[0040]
A graphic synthesizer (GS) 404 and an input / output processor (IOP) 409 are connected to the bus 403, respectively. The GS 404 includes a RAM (image memory) 405 including a frame buffer, a Z buffer, a texture memory, and the like, and a rendering engine (RE) 406 having a rendering function including a drawing function to the frame buffer in the RAM 405.
[0041]
A monitor 18 as an external device is connected to the GS 404 configured as described above via an encoder 407 for converting a digital RGB signal or the like into an NTSC standard television system, for example.
[0042]
The IOP 409 includes a driver (DRV) 410 for reproducing and decoding data recorded on the optical disc 20, a sound generation system 412, a memory card 14 as an external memory including a flash memory, a controller 16, an operating system, and the like. The ROMs 416 on which are recorded are respectively connected. The sound generation system 412 is connected to a speaker 414 and a monitor 18 as external devices via an amplifier 413, and supplies an audio signal.
[0043]
The sound generation system 412 stores a sound processing unit (SPU) 420 that generates musical sounds, sound effects, and the like, and a musical sound, sound effects, etc. generated by the SPU 420 based on instructions from the CPU 401. Sound buffer 422. Signals such as musical sounds and sound effects generated by the SPU 420 are supplied to the audio terminals of the speaker 414 and the monitor 18 and output (sound) as musical sounds, sound effects and the like from the speakers of the speaker 414 and the monitor 18. Yes.
[0044]
Here, the SPU 420 is stored in the sound buffer 422 and an ADPCM decoding function for reproducing, for example, adaptive predictive coding (ADPCM: Adaptive Differential PCM) using 16-bit audio data as a 4-bit differential signal. A reproduction function for generating sound effects and the like by reproducing waveform data, a modulation function for reproducing waveform data stored in the sound buffer 422, and the like are provided.
[0045]
By providing such a function, the sound generation system 412 can be used as a so-called sampling sound source that generates musical sounds, sound effects, and the like based on the waveform data recorded in the sound buffer 422 according to instructions from the CPU 401. It is like that.
[0046]
The memory card 14 is a card-type external storage device comprising, for example, a CPU or a gate array and a flash memory, and is removable from the entertainment device 12 shown in FIG. The game state during the game is stored, and a DVD playback program and the like are stored.
[0047]
The controller 16 is for giving a command (a binary command or a multi-value command) to the entertainment device 12 by pressing a plurality of buttons. The driver 410 includes a decoder for decoding an image encoded based on the MPEG (moving picture experts group) standard.
[0048]
The CPU 401 includes a random number generator (not shown).
[0049]
By the way, when drawing a tree object as a three-dimensional image, it is generally considered that the tree object is divided into a trunk object and a large number of leaf objects. When drawing both the stem and leaf objects in a normal rendering process, the leaf object is drawn with a plurality of polygons and fixed coordinates, as in the case of the trunk object.
[0050]
However, it is clear that the amount of data is enormous because it is necessary to have each vertex data for a plurality of polygons constituting one leaf.
[0051]
Therefore, in the present embodiment, the trunk object adopts a data structure in which vertex data is provided for each of the polygons constituting the trunk object as usual, but the leaf object is shown in FIG. As shown, it is drawn with a single rectangular or square polygon. Actually, a leaf texture is pasted on a rectangular polygon.
[0052]
In this case, if one side is oriented in the vertical direction in world coordinates, one vertex is determined and the other vertex is automatically determined at the same time, which greatly increases the amount of vertex data related to the polygon. It becomes possible to reduce it.
[0053]
FIG. 5 shows an example in which a trunk object and a large number of leaf objects are drawn as seen from the plane.
[0054]
There is one problem with such a drawing method. That is, when a tree object is viewed from a certain viewpoint, the polygons constituting the leaves are viewed as trees with leaves over because all the polygon faces are in the direction of the virtual viewpoint e. However, when the viewpoint is turned by 90 °, for example, to make the virtual viewpoint ea, all polygon surfaces are arranged at an angle of 90 ° ± a ° with respect to the direction of the viewpoint for the polygons constituting the leaves. Therefore, when the tree is viewed from this viewpoint, the texture of the leaves can hardly be seen, resulting in a fallen trunk, resulting in inconvenience in display.
[0055]
Therefore, in the present embodiment, in addition to the above-described method, the above-mentioned problems are solved by drawing the polygon surfaces of the polygons constituting the leaves in the direction of the viewpoint.
[0056]
Specifically, several drawing methods according to the present embodiment will be described with reference to FIGS. A series of processing is performed by the CPU 401 and the RE 406, and the RAM 402, the image memory 405, and the like are used as a working memory.
[0057]
FIG. 6A is a ZX plan view of the virtual space 100. The virtual space 100 is virtually set for arranging objects and polygons for drawing an image. This virtual space 100 is a three-dimensional space, and the X axis is oriented horizontally to the image plane to be drawn, the Y axis corresponding to the height direction of the image plane to be drawn (see FIG. 6C), and the Z axis perpendicular to the image plane to be drawn. Has an axis.
[0058]
In addition, the actual general CG method has a world coordinate system that is not influenced by the image plane in addition to the coordinate system (screen coordinate system) based on the orientation of the image plane.
[0059]
In the virtual space 100, the object and the trunk of the trunk 102 extending in the Y-axis direction are between the virtual viewpoint e serving as a reference for drawing and the virtual screen (background plane) Z0 perpendicular to the Z-axis on which the image is drawn. A plurality of leaf polygons 104a provided in the vicinity of the object 102 are arranged. The leaf polygon 104a (see also FIG. 4) is a rectangle, the four vertices of the leaf polygon 104a are represented as 104a1 to 104a4, and the vertices 104a1 and 104a4 are configured to be diagonal. The leaf polygon 104a does not necessarily display only a leaf picture, but may include a branch picture. Also, the number of leaf pictures need not be one, but may be a plurality.
[0060]
FIG. 6B is an enlarged view of one of the leaf polygons 104a in FIG. 6A. Here, V is a normal vector based on the reference point Lo of the leaf polygon 104a, and Ve is a viewpoint vector indicating the direction of the virtual viewpoint e with the reference point Lo as the base point. When the leaf polygon 104a is rotated by an angle θ1 formed between the normal vector V and the viewpoint vector Ve, a converted polygon 104b is obtained. When the converted polygon 104b is projected on the screen Z0 based on the virtual viewpoint e, a leaf projection surface 104c is obtained.
[0061]
FIG. 6C is a ZY plan view of the virtual space 100 in which the positional relationship among the trunk 102, the converted polygon 104b, the virtual viewpoint e, and the leaf projection plane 104c is clarified. The projection relationship on the ZX plane shown in FIG. 6A is the same on the ZY plane.
[0062]
In the image drawing method according to the first embodiment, as shown in FIGS. 6A and 6B, the normal V of the polygon surface of the leaf polygon 104a in an arbitrary direction arranged around the trunk 102 in advance is used as a reference. The converted polygon 104b is obtained by rotating it so as to coincide with a straight line connecting the point Lo and the virtual viewpoint e. Next, a calculation for projecting the converted polygon 104b onto the screen surface Z0 is performed to obtain a leaf projection surface 104c.
[0063]
A specific method of the image drawing method according to the first embodiment will be described with reference to FIGS. 6A to 16.
[0064]
As shown in FIG. 7, tree drawing can be divided into three processes: initialization processing (step S1), trunk drawing processing (step S2), and leaf drawing processing (step S3).
[0065]
In the initialization process (step S1), the object information table 106 shown in FIG. 8, the polygon information table 108 of the trunk shown in FIG. 9, the polygon information table 110 of the leaf shown in FIG. The texture map, which is the polygon pattern data, is loaded into the texture memory of the image memory 405.
[0066]
The object information table 106 is information including the reference absolute coordinate T0 of the trunk, the number of trunk polygons Nm, the trunk polygon information table address ADm, the number of branches Nb, and the branch vector information table address ADb.
[0067]
The stem polygon information table 108 has information on Nm trunk polygons. The stem polygon information includes the relative position coordinates of the four vertices 104a1 to 104a4 of the polygon, the color data of the four vertices 104a1 to 104a4, and Texture map address ADt _i including. i represents the number of the polygon of the trunk, and takes a numerical value of 0 to Nm-1.
[0068]
The trunk drawing (step S2) will be described with reference to FIG.
[0069]
First, in step S101, the number Nm of trunk polygons, the reference absolute coordinates T0 of the trunk, and the address ADm of the trunk polygon information table 108 are secured in a register or the like from the object information table 106 shown in FIG.
[0070]
In step S102, the initial value “0” is stored in the counter i, and the counter i is initialized.
[0071]
In step S103, the trunk polygon information indicated by the counter i is read from the stem polygon information table 108 indicated by the address ADm.
[0072]
In step S104, the reference absolute coordinate T0 of the trunk is added to the relative coordinates of the four vertices 104a1 to 104a4 in the read polygon information of the trunk. In this way, the world coordinate values of the four vertices 104a1 to 104a4 of the leaf polygon 104a are obtained. Further, a relative position Zr on the Z axis with respect to the screen Z0 is obtained from the world coordinate values of the four vertices 104a1 to 104a4.
[0073]
Next, color correction, projection processing onto the screen Z0, and the like are performed. These processing steps S105 to S108 are generally called rendering processing.
[0074]
In the rendering process, first, in step S105, the color of the converted polygon is calculated. First, using the color data of the four vertices 104a1 to 104a4 included in the polygon information of the trunk 102, the color within the range of the converted polygon 104b is corrected. Then, the surface brightness is obtained by performing optical calculation from information on a virtual light source (not shown), and the texture of the surface is further corrected.
[0075]
In step S106, a leaf projection surface 104c (see FIG. 6A) obtained by projecting the converted polygon 104b onto the screen Z0 is obtained.
[0076]
In step S107, the texture map address ADt of the polygon information is applied to the projection plane range. _i A drawing image is obtained by adding the texture indicated by the above to the shape of the projection surface.
[0077]
In step S108, the obtained drawing image is written in the display buffer of the RAM 405, and the relative position Zr on the Z axis is written in the Z buffer of the RAM 405.
[0078]
In step S109, after updating the counter i by +1, it is determined in the next step S110 whether the processing is completed. That is, if i and Nm are equal, all the processing has been completed for the trunk polygon, and the processing moves to the leaf drawing processing (step S3) shown in FIG. If i and Nm are different (if i is smaller than Nm), the process returns to step S103 to repeat the process.
[0079]
Next, leaf drawing (step S3) will be described with reference to FIG.
[0080]
First, in step S201, the number Nl of leaf polygons 104a to be drawn is determined. The number Nl of leaf polygons 104a is determined in advance and may be stored in the optical disc 20 or the like, or the number of leaf polygons 104a corresponding to the shape of the trunk 102 drawn in step S1 is appropriately determined. May be.
[0081]
Then, in step S202, a process for determining the placement of leaves is performed, and in step S203, a process rendering process for determining the orientation of leaves is performed, thereby rendering the leaves. Among these, the process of step S202 will be described later.
[0082]
In the process of determining the orientation of the leaves in step S203, first, in step S203a, the counter i is first initialized to “0” as an internal process. Next, in step S203b, the orientation of the leaf indicated by the counter i is determined. Details of the processing in step S203b will be described later.
[0083]
In step S203c, after updating the counter i by +1, it is determined whether the processing is completed in the next step S203d. In other words, if i and Nl are equal, all the processing has been completed for the trunk polygon, and the process proceeds to rendering processing (step S204). If i and Nl are different (if i is smaller than Nl), the process returns to step S203b and the process is repeated.
[0084]
The rendering process in step S204 is the same process as steps S105 to S108 described in the trunk drawing process, and thus detailed description thereof is omitted.
[0085]
The processing for determining the arrangement of leaves in FIG. 11 (step S202) will be described with reference to FIGS. 12 and 13 showing the processing contents.
[0086]
First, in step S301, an initial value “0” is stored in the counter i, and the counter i is initialized.
[0087]
In step S302, the leaf polygon information indicated by the counter i is read from the leaf polygon information table 110.
[0088]
As shown in FIG. 13, each leaf polygon information table 110 has substantially the same configuration as the trunk polygon information table 108, and represents a leaf as one polygon. That is, the relative coordinate values of the four vertices 104a1 to 104a4, the color data of the four vertices 104a1 to 104a4, and the texture map address ADl. _i It is the structure which has. The relative coordinates of the four vertices 104a1 to 104a4 are set so as to form a plane. Further, the leaf polygon information table 110 has information on the number Nl of leaves to be drawn.
[0089]
In step S303, the relative coordinate values of the four vertices 104a1 to 104a4 are converted into absolute coordinates based on the reference absolute coordinate T0 of the trunk 102, and the four vertices 104a1 of the leaf polygon 104a indicated by the counter i are converted. The world coordinate values of ˜104a4 are determined. Thus, since the leaf position information is composed of relative coordinates, it is possible to cope with the trunk 102 wherever the virtual space 100 is arranged.
[0090]
In step S304, after updating the counter i by +1, it is determined in the next step S305 whether the process is completed. In other words, if i and Nl are equal, all the processing has been completed for the trunk polygon, and the processing moves to the leaf drawing processing (step S203) in FIG. If i and Nl are different (if i is smaller than Nl), the process returns to step S301 to repeat the process.
[0091]
Next, processing for determining the orientation of the leaf indicated by the counter i in FIG. 11 (step S203b) will be described with reference to FIGS. 6A, 6B, 15 and 16. FIG. Several methods can be considered for determining the leaf orientation, and FIGS. 15 and 16 are flowcharts showing the types of processing for determining the leaf orientation. Of these, the method for determining the orientation of the leaves according to the first embodiment will be described.
[0092]
First, in step S401, it is determined whether or not the orientation of the leaf polygon 104a has been determined in the processing performed in step S202. In the first embodiment, the information of the leaf polygon 104a has the world coordinate values of the four vertices 104a1 to 104a4, and the coordinates of the four vertices 104a1 to 104a4 are set to form a plane. Therefore, the direction of the leaves is uniquely determined. Accordingly, the process proceeds to the next step S402.
[0093]
In step S402, a leaf normal vector V is calculated from the world coordinate values of the four vertices 104a1 to 104a4. Since the four vertices 104a1 to 104a4 are set so as to constitute a plane, the normal vector V may be calculated for two vectors obtained by selecting three of them.
[0094]
Next, in step S403, it is determined whether or not to consider whether the direction of the normal vector V is an inconvenient display direction with respect to the virtual viewpoint e. This determination is determined in advance by the image producer in consideration of the processing speed and the like, and may not be determined by the CPU 401. When the normal vector V is not considered, that is, when the orientation of the leaf polygon 104a is uniformly changed, the process proceeds to step S405.
[0095]
When the normal vector V is considered, the process proceeds to step S404, and the direction of the normal vector V is determined. In this determination, a straight line vector connecting the reference point Lo of the leaf polygon 104a and the virtual viewpoint e is set as the viewpoint vector Ve, and an angle θ1 formed by the viewpoint vector Ve and the normal vector V is calculated. When the obtained angle θe is within 90 ° ± a °, the leaves are in an inconvenient display because the leaves are oriented substantially parallel to the virtual viewpoint e. Therefore, the process moves to step S405 to change the orientation of the leaves. If the angle is other than that, the process shown in FIG. 15 is terminated assuming that the direction of the leaf is not changed. Here, a ° is determined arbitrarily by the image producer, but is generally a numerical value within 45 °.
[0096]
In steps S405 and S405a, it is determined on what basis to change the leaf orientation. This determination may be determined in advance by the image producer. In the first embodiment, the process proceeds to step S406.
[0097]
In step S406, the leaf polygon 104a is rotated so as to face the virtual viewpoint e. The rotation process will be described with reference to FIGS. 6A and 6B.
[0098]
The normal vector V is rotated by an angle θ1 around the reference point Lo of the leaf polygon 104a so that the normal vector V coincides with the viewpoint vector Ve. That is, the coordinate values of the converted polygon 104b to which the four vertices 104a1 to 104a4 of the polygon 104a are moved by the rotation are calculated. FIG. 6B shows an example in which the reference point Lo is set to one of the four vertices 104a1 to 104a4 of the leaf polygon 104a, for example, the vertex 104a1. In this way, if one of the four vertices 104a1 to 104a4 is taken as the reference point Lo, only the remaining three vertices need be calculated.
[0099]
Also, by setting the leaf polygon 104a to be rectangular or square and the normal vector V to be parallel to the ZX plane, two diagonal vertices of the leaf polygon 104a, for example, the vertex 104a1 and If only the vertex 104a4 is calculated and the converted positions after rotation are obtained, the remaining two vertices 104a2 and 104a3 can be expressed by conversion from the converted positions of the results of the calculations for the vertices 104a1 and 104a4. Furthermore, in this case, if the reference point Lo is set to one of the four vertices 104a1 to 104a4, for example, 104a1, if the converted position after rotation is obtained for only one point of the diagonal vertex 104a4, Since other vertices can be expressed in terms of conversion, the amount of calculation is greatly reduced.
[0100]
In addition, since the information necessary for the leaf polygon 104a is only information on one vertex among the plurality of vertices, the amount of data can be reduced.
[0101]
Thus, since the converted polygon 104b obtained by rotating the polygon 104a faces the virtual viewpoint e, there is no inconvenience in display.
[0102]
Since the leaf orientation has been determined, step S203b in FIG. 11 ends. This process is executed according to the control process of the counter i (step S203a, step S203c and step S203d), and when the orientation is determined for the Nl leaf polygon 104a, the process may be shifted to the rendering process (step S204).
[0103]
Note that the processing for determining the leaf orientation (step S203) has been described on the ZX plane with reference to FIGS. 6A and 6B, but in reality, the leaf polygon 104a may be rotated in the three-dimensional space. Good.
[0104]
A method of rotating the leaf polygon 104a in the three-dimensional space will be described with reference to FIGS. 14A and 14B. 14A and 14B have the same orientation as the axes of the screen coordinate system, but the origin of the screen coordinate system is ignored and only the relative direction is represented. .
[0105]
FIG. 14A is a diagram illustrating a state in which the normal vector V of the leaf polygon 104a is rotated on the ZX plane in the direction of the viewpoint vector Ve.
[0106]
Vy and Vey are two-dimensional vectors of ZX plane components of the normal vector V and the viewpoint vector Ve, respectively. θ11 is an angle formed by the two-dimensional vectors Vy and Vey. V1 is a vector obtained by rotating the normal vector V by an angle θ11 around the Y axis.
[0107]
FIG. 14B shows a two-dimensional coordinate constituted by a two-dimensional vector Vey and the Y axis. θ12 is an angle formed by the rotated vector V1 and the viewpoint vector Vey.
[0108]
In order to orient the leaf polygon 104a in the direction of the virtual viewpoint e, first, a first rotation process for rotating the leaf normal vector V about the Y axis by an angle θ11 is performed. By this processing, the normal vector V moves to the position of the vector V1. In this state, the ZX plane component of the vector V1 after movement and the viewpoint vector Ve match.
[0109]
Next, a second rotation process is performed in which the moved vector V1 is rotated by an angle θ12 in the two-dimensional coordinate system shown in FIG. 14B. By this processing, the vector V1 coincides with the viewpoint vector Ve, and the leaf polygon 104a faces the virtual viewpoint e.
[0110]
Note that the rotation processing may be performed directly in the direction from the normal vector V to the viewpoint vector Ve in the three-dimensional space without dividing the rotation processing twice.
[0111]
Furthermore, in the above description, as shown in FIG. 11, all leaf arrangements are determined in step S202, and then the leaf orientation is determined in step S203. You may process so that the direction of a leaf and the arrangement | positioning of a leaf may be determined continuously.
[0112]
The polygon is not limited to a rectangle such as a rectangle or a square, but may be a triangle or a pentagon.
[0113]
As described above, in the image drawing method according to the first embodiment, since the leaf polygons are all directed toward the virtual viewpoint e, the polygons are not difficult to see from the virtual viewpoint e.
[0114]
Further, since the leaf polygon information table 110 is provided, the arrangement, color, and texture can be freely set for individual leaves, so that the degree of freedom in expression is high.
[0115]
Furthermore, by making the shape of the leaf polygon 104a rectangular and setting the rotation reference point as the vertex of the polygon, the amount of calculation related to rotation can be greatly reduced.
[0116]
Next, an image drawing method according to the second embodiment will be described with reference to FIGS. 17A to 18.
[0117]
In the second embodiment, substantially the same processing as in the first embodiment is performed, but in the processing of rotating the leaf polygon 104a, the direction of rotation is different. That is, as shown in FIGS. 17A and 17B, the polygon 104a is rotated in the Z-axis direction to obtain a converted polygon 104d.
[0118]
Specifically, in the process in FIG. 15, the process proceeds from step S405 to step S407 via the branch process in step S405a.
[0119]
In step S407, the leaf polygon 104a is rotated in the direction of the Z-axis. The rotation process will be described with reference to FIGS. 17A and 17B.
[0120]
FIG. 17A is a ZX plan view of the virtual space 100 according to the second embodiment. Reference numeral 104d denotes a converted polygon obtained by rotating the polygon 104a in the Z-axis direction. The other symbols are the same as in FIG. 6A. FIG. 17B is an enlarged view of the leaf polygon 104a portion of FIG. 17A. Vz is a Z-axis vector indicating the Z-axis direction starting from the reference point Lo of the leaf polygon 104a. The angle θ2 is an angle formed by the normal vector V and the Z-axis vector Vz.
[0121]
The normal vector V is rotated by an angle θ2 around the reference point Lo so that the normal vector V coincides with the Z-axis vector Vz. That is, the coordinate values of the converted polygon 104d to which the four vertices 104a1 to 104a4 of the polygon 104a are moved by the rotation are calculated. Thus, when rotating in the direction of the Z-axis, there is an effect that the calculation is simplified without considering the direction of the virtual viewpoint e. Also, since the leaves are directed in the Z-axis direction, they are different from the direction of the virtual viewpoint e, but are parallel to the screen Z0, so that they are not particularly difficult to see in image drawing.
[0122]
Further, if the method for selecting the reference point Lo and the polygon shape setting are the same as in the first embodiment, the amount of calculation can be reduced.
[0123]
Since the leaf orientation has been determined, step S203b in FIG. 11 ends. This process is executed according to the control process of the counter i (step S203a, step S203c and step S203d), and when the orientation is determined for the Nl leaf polygon 104a, the process may be shifted to the rendering process (step S204).
[0124]
Note that the processing for determining the leaf orientation (step S203) has been described on the ZX plane with reference to FIG. 17B, but the leaf polygon 104a may actually be rotated in the three-dimensional space.
[0125]
A method of rotating the leaf polygon 104a in the three-dimensional space will be described with reference to FIG.
[0126]
FIG. 18 is a diagram illustrating a state in which the normal vector V of the leaf polygon 104a is rotated on the ZX plane in the direction of the Z-axis vector Vz.
[0127]
In FIG. 18, the positional relationship between the coordinates and the normal vector V and the two-dimensional vector Vy are the same as those in FIG. 14A. The angle θ21 is an angle formed by the two-dimensional vector Vy and the Z-axis vector Vz. V2 is a vector obtained by rotating the normal vector V about the Y axis by an angle θ21. The angle θ22 is an angle formed by the rotated vector V2 and the Z-axis vector Vz.
[0128]
In order to orient the leaf polygon 104a in the direction of the Z-axis vector Vz, first, a first rotation process is performed to rotate the leaf normal vector V about the Y axis by an angle θ21. By this processing, the normal vector V moves to the position of the vector V2. In this state, the ZX plane component of the vector V1 after movement and the Z-axis vector Vz coincides.
[0129]
Next, a second rotation process for rotating the vector V2 after movement on the ZY plane by an angle θ22 is performed. With this processing, the vector V2 coincides with the Z-axis vector Vz, and the leaves are directed in the Z-axis direction.
[0130]
In addition, even if it does not calculate in two steps in this way, you may process so that it may rotate directly in the direction of the normal vector V to the Z-axis vector Vz on a three-dimensional space.
[0131]
As described above, in the image drawing method according to the second embodiment, since all the leaves are directed in the Z-axis direction, the amount of calculation of rotation is small, and particularly when viewed from the virtual viewpoint e. It is not difficult to see.
[0132]
Next, an image drawing method according to the third embodiment will be described with reference to FIG. 15, FIG. 16, and FIG.
[0133]
In the third embodiment, almost the same processing as that in the first embodiment is performed, but the rotation processing is different in the processing of rotating the leaf polygon 104a. In other words, it is not directed in a specific direction, but is directed in an arbitrary direction by a random number obtained by a random number generator.
[0134]
Specifically, in the process in FIGS. 15 and 16, the process proceeds from step S405 to step S408 via the branch process in step S405a.
[0135]
In step S408, several random numbers are obtained by a random number generator. Then, a random number vector Vr (see FIG. 19) pointing in a certain direction is set by this random number.
[0136]
Consider a range of a quadrangular pyramid Py centered on the Z-axis as shown in FIG. In FIG. 19, x0 and y0 are an X coordinate value and a Y coordinate value that define the quadrangular pyramid Py, respectively. x1 and y1 are the X coordinate value and the Y coordinate value of the random number vector Vr to be set. z1 is the Z coordinate value of the random number vector Vr.
[0137]
The Z-axis coordinate value z1 of the random number vector Vr, the X-axis coordinate value x0 that defines the quadrangular pyramid, and the Y-axis coordinate value y0 are set to appropriate values. The X-axis coordinate value x0 and the Y-axis coordinate value y0 are preferably smaller than the Z-axis coordinate value z1. Next, two random numbers are acquired by a random number generator. This random number generator generates a value within a range of ± 1. Then, the obtained two random numbers are multiplied by the X-axis coordinate value x0 and the Y-axis coordinate value y0, respectively, to obtain the X-axis coordinate value x1 of the random number vector Vr and the Y-axis coordinate value y1 of the random number vector Vr. This value is combined with the Z-axis coordinate value z1 to define the random number vector Vr (x1, y1, z1). The random number vector Vr indicates a direction within the range of ± x0 on the X axis and ± y0 on the Y axis with the Z axis as the center.
[0138]
If the random number vector Vr is defined, the process proceeds to step S409.
[0139]
In step S409, the direction of the random number vector Vr obtained in step S408 is determined. This determination is made by calculating the angle formed by the viewpoint vector Ve and the random number vector Vr. When the obtained angle is within 90 ° ± a °, the leaves are in an inconvenient display because the leaves are oriented substantially parallel to the virtual viewpoint e. Accordingly, the process moves to step S408 to change the orientation of the leaves. If the angle is any other angle, the process proceeds to the next step S410 assuming that the leaf orientation is not changed.
[0140]
In step S410, the leaf polygon 104a is rotated so that the orientation of the leaf polygon 104a is directed to the direction of the random number vector Vr. This rotation processing is to rotate in the direction of the random number vector Vr instead of the viewpoint vector Ve in FIGS. 6A, 6B, 14A, and 14B described in the first embodiment. Since the processing procedure is the same, detailed description thereof is omitted.
[0141]
Since the leaf orientation has been determined, step S203b in FIG. 11 ends. This process is executed according to the control process of the counter i (step S203a, step S203c and step S203d), and when the orientation is determined for the Nl leaf polygon 104a, the process may be shifted to the rendering process (step S204).
[0142]
Note that the processing for determining the orientation of the leaves (step S203) is set so that the random number vector Vr faces the direction within the range of the quadrangular pyramid Py with reference to FIG. 19, but this range is indicated by the quadrangular pyramid Py. It does not have to be set, and it may be directed in any direction without setting a range.
[0143]
As described above, in the image drawing method according to the third embodiment, since the orientation of the leaf polygon 104a is determined using a random number, the orientation of each leaf is set differently, and the natural atmosphere of the plant Can be expressed.
[0144]
In addition, since a process for resetting the direction of leaves that are substantially parallel to the direction of the virtual viewpoint e is performed, it is not particularly difficult to see from the virtual viewpoint e.
[0145]
In the first to third embodiments described above, the drawing method has been described so that the orientation of the leaf polygon 104a becomes an appropriate direction. In the following fourth to sixth embodiments, a method of arranging the leaf polygon 104a around the trunk 102 will be described.
[0146]
An image drawing method according to the fourth embodiment will be described with reference to FIGS. 15, 16, 20, and 21.
[0147]
In the fourth embodiment, substantially the same processing as in the first embodiment is performed, but the processing for arranging the leaf polygon 104a is different. In other words, the arrangement position is determined for each leaf object by using a random number.
[0148]
Specifically, the processing shown in FIG. 15, FIG. 16 and FIG. 20 is performed as the processing contents of the processing for determining the placement of leaves in FIG.
[0149]
FIG. 21 shows an example in which the reference absolute coordinate T1 is set at a substantially central portion of the trunk 102, and the space range S for drawing the leaves is set to a spherical body with a radius r.
[0150]
In step S501 in FIG. 20, a reference absolute coordinate T1 for drawing a leaf is appropriately determined. The reference absolute coordinate T1 may be determined based on the coordinate value of the trunk 102.
[0151]
Next, in step S502, a range S of a space for drawing leaves is set with reference to the reference absolute coordinate T1. The range S may be a shape such as a spherical body, an ellipsoid, a cylinder, or a cone. Hereinafter, the range S will be described as a spherical body (see FIG. 21).
[0152]
In step S503, an initial value “0” is stored in the counter i, and the counter i is initialized.
[0153]
In step S504, three random numbers are generated by the random number generator of the CPU 401, and the random number is matched with the range S to obtain the reference position of the leaf. Specifically, the three random numbers obtained by the random number generator are set as q1, q2, q3 and using the radius r,
K = r / (sqr (q1 * q1 + q2 * q2 + q3 * q3))
A constant value K is obtained. Here, sqr (...) is a square root function.
[0154]
Then, the constant value K is multiplied by q1, q2, and q3, respectively, and one of the four vertices 104a1 to 104a4 of the leaf polygon 104a, for example, the X-axis relative coordinate value r1 and the Y-axis relative coordinate value of the vertex 104a1. r2 and the Z-axis relative coordinate value r3 are obtained.
[0155]
When the relative coordinate values (r1, r2, r3) of one vertex 104a1 of the leaf polygon 104a are obtained, the relative coordinate values are converted into world coordinate values using the reference absolute coordinate T1 as a reference, and the th leaf indicated by the counter i is displayed. Is stored in the RAM 402 or the like as the position of one vertex 104a1 of the polygon 104a.
[0156]
In step S505, after updating the counter i by +1, it is determined in step S506 whether the processing is completed. That is, if i and Nl are equal, the arrangement of one vertex 104a1 of the Nl leaf polygon 104a has been determined, so the processing shown in FIG. 20 is terminated, and the process proceeds to step S203 shown in FIG. If i and Nl are different (if i is smaller than Nl), the process returns to step S504 and the process is repeated.
[0157]
When the arrangement of the leaf polygon 104a is determined, step S202 in FIG. 11 is completed.
[0158]
Next, the process proceeds to the process of determining the orientation of the leaves in FIG. 11 (step S203). The process is the same as that of the first embodiment except for the process of determining the orientation of the leaf to be drawn indicated by the counter i (step S203b).
[0159]
In FIG. 15 and FIG. 16 describing step S203b, first, in step S401, it is determined whether or not the orientation of the leaf is uniquely specified. In the fourth embodiment, since the leaf polygon 104a has only the coordinates of one vertex 104a1 among the four vertices 104a1 to 104a4, the orientation is not specified.
[0160]
Accordingly, the process proceeds to step S411 in FIG. 16 to temporarily specify the orientation of the leaf polygon 104a. Here, it is defined in the Z-axis direction, which is the same direction as in the second embodiment.
[0161]
The subsequent processing is the same as in the case of the first embodiment and the second embodiment. 15 and 16, step S412 and step S412a are step S405 and step S405a, step S413 is step S406, step S414 is step S408, step S415 is step S409, and step S416 is step S410. Each corresponds.
[0162]
Although there is no processing corresponding to step S407 in the case of the second embodiment, since the initial direction is the same as that in the case of the second embodiment, the processing after branching in step S412a is unnecessary, and as a result Step S407 is not necessary.
[0163]
This completes the process of determining the orientation of the leaves in FIG. 11 (step S203), and thereafter, the process may be performed in the same manner as in the first embodiment.
[0164]
As described above, in the image drawing method according to the fourth embodiment, since the arrangement of the leaf polygon 104a is determined using random numbers, the image producer only needs to determine the number of leaves Nl. No modeling work is required. Moreover, any number of trees having different leaf arrangements can be constructed.
[0165]
Next, an image drawing method according to the fifth embodiment will be described with reference to FIGS. 22, 23A, 23B, and 23C.
[0166]
In the fifth embodiment, almost the same processing as that of the first embodiment is performed, but the processing for arranging the leaf polygon 104a is different. That is, the arrangement position is determined for each leaf object by using a predetermined function.
[0167]
Specifically, the processing shown in FIG. 15, FIG. 16, and FIG. 22 is performed as the processing contents of the processing for determining the arrangement of the leaves to be drawn (step S202) in FIG.
[0168]
FIG. 23A shows an example in which the X-axis relative coordinate value r1 is calculated using a function f obtained by modifying a normal distribution function whose maximum value is r. The function f is obtained by reversing the vertical axis of the normal distribution function. By using this function f, a value relatively close to 0 is obtained for the counter i, and a value close to the radius r is decreased. Also, a value greater than the radius r is not possible.
[0169]
FIG. 23B is also an example of calculating the Y-axis relative coordinate value r2 using a function g obtained by modifying a normal distribution function whose maximum value is r. The function g is obtained by dividing the normal normal distribution function into two and shifting the phase, and a value different from the function f can be obtained.
[0170]
FIG. 23C is an example of calculating the Z-axis relative coordinate value r3 using a linear function as the function h. Since it does not require a complicated operation like the normal distribution function, it can be calculated easily.
[0171]
In step S601 in FIG. 22, a reference absolute coordinate T1 for drawing a leaf is appropriately determined. Further, in step S602, a space range S in which leaves are drawn with reference absolute coordinates T1 as a reference is set. The reference absolute coordinate T1 and the range S are as described in the fourth embodiment. In the following description, the range S is a spherical body having a radius r (see FIG. 21).
[0172]
Next, in step S603, an initial value “0” is stored in the counter i, and the counter i is initialized.
[0173]
In step S604, the arrangement of one of the four vertices 104a1 to 104a4 of the leaf polygon 104a, for example, the vertex 104a1, is determined by an appropriate function. Three functions are prepared.
r1 = f (i, r)
r2 = g (i, r)
r3 = h (i, r)
And The functions f, g, and h determine values based on the counter i and the radius r, respectively.
[0174]
Examples of functions f, g, and h are shown in FIGS. 23A, 23B, and 23C.
[0175]
These functions f, g, and h may be set as appropriate, and may be other than the above. Further, the horizontal axis values of the functions f, g, and h may not be sequentially increased by the counter i, but may be selected at random using random numbers or the like.
[0176]
In this way, the relative coordinates (r1, r2, r3) of one vertex 104a1 among the four vertices 104a1 to 104a4 of the leaf polygon 104a distributed within the spherical range S of radius r are determined.
[0177]
This relative coordinate value is converted into a world coordinate value based on the reference absolute coordinate T1, and stored in the RAM 402 as the position of one vertex 104a1 of the four vertices 104a1 to 104a4 of the leaf polygon 104a indicated by the counter i.
[0178]
In step S605, after the counter i is updated by +1, it is determined in step S606 whether the processing is completed. In other words, if i and Nl are equal, the arrangement of the Nl leaf polygons 104a has been determined, so the processing shown in FIG. 20 is terminated and the process proceeds to step S203 shown in FIG. If i and Nl are different (if i is smaller than Nl), the process returns to step S604 and the process is repeated.
[0179]
When the arrangement of the leaf polygon 104a is determined, step S202 in FIG. 11 is completed.
[0180]
Next, the process proceeds to the process of determining the leaf orientation shown in FIGS. Since these processes are the same as those in the fourth embodiment, a detailed description thereof will be omitted.
[0181]
Further, after the process of determining the leaf orientation is completed, the process may be performed in the same manner as in the first embodiment.
[0182]
As described above, in the image drawing method according to the fifth embodiment, the layout of leaf polygons is determined using a function, so the image producer determines only the number of leaves Nl and the functions f, g, and h. As a result, normal modeling work becomes unnecessary, and by using a normal distribution function or the like, the center is dense with the reference absolute coordinate T1 as the center, and it becomes rougher toward the radius r. The arrangement of the leaves can be realized and the natural atmosphere of the plant can be expressed.
[0183]
Next, an image drawing method according to the sixth embodiment will be described with reference to FIGS.
[0184]
In the sixth embodiment, almost the same processing as in the first embodiment is performed, but the processing for arranging the leaf polygon 104a is different. That is, the branch vector Vb of the trunk 102 _i By preparing (see FIG. 26), this branch vector Vb _i The leaf polygon 104a is arranged on the top. Note that i is the value of the counter i.
[0185]
Specifically, the processing shown in FIG. 15, FIG. 16 and FIG. 24 is performed as the processing content of the processing for determining the placement of leaves in FIG.
[0186]
The branch vector information table 112 shown in FIG. 25 includes Nb branch vectors Vb. _i Each branch vector information is a branch vector Vb with respect to the reference. _i Relative coordinates, angle data and length L _i including.
[0187]
FIG. 26 shows the branch vector Vb. _i FIG. Where branch vector Vb _i Indicates Nb branches with respect to the trunk 102, and its starting point is expressed in relative coordinates. That is, it is possible to deal with the trunk 102 wherever it is arranged in the virtual space 100. The branch vector Vb _i Angle and size L _i It shall be represented in the polar coordinate format represented by
[0188]
FIG. 27 shows a vector Vb indicating the position of one vertex 104a1 of the four vertices 104a1 to 104a4 of the leaf polygon 104a. _ij FIG. Vector Vb _ij Is the branch vector Vb _i Indicates that only the size is changed in the same direction as.
[0189]
In step S701 in FIG. 24, data relating to the branches of the trunk 102 is read. That is, the number Nb of branches, the branch vector information table address ADb, and the branch vector information table 112 shown in FIG. 25 are read in the object information table 106 (see FIG. 8).
[0190]
Next, in step S702, the initial value “0” is stored in the counter i, and the counter i is initialized.
[0191]
Proceeding to step S703, the branch vector Vb indicated by the counter i from the branch vector information table 112 indicated by the address ADb. _i Read the information.
[0192]
In step S704, the branch vector Vb _i Number of leaves for Nb _i To decide. Nb for simplicity of explanation _i = Nl / Nb. That is, the total number of all leaves is set to Nl as in the other embodiments.
[0193]
In step S705, the initial value “0” is stored in the counter j, and the counter j is initialized.
[0194]
Moving to step S706, the branch vector Vb indicated by the counter i _i The branch vector Vb _i Nb above _i The arrangement of the leaf polygons 104a is calculated.
[0195]
That is, as shown in FIGS. 25 and 27, the branch vector Vb _i The size of L _i Therefore, the branch vector Vb _i The direction is the same and the size is L _i × j / Nb _i Relative coordinate vector Vb of one vertex 104a1 of the leaf polygon 104a _ij Ask for. Then, the relative coordinate value is converted into a world coordinate value based on the reference absolute coordinate T1, and (i × Nb _i ) The position of the + jth leaf is stored in the RAM 402 or the like.
[0196]
In step S707, after updating the counter j by +1, it is determined in step S708 whether the processing is completed. That is, the counter j and the branch vector Vb _i Number of leaves Nb _i If they are equal, the process proceeds to step S709. j and Nb _i Are different (j is Nb _i If smaller, the process returns to step S706 to perform the next process.
[0197]
Further, after updating the counter i by +1 in step S709, it is determined whether or not the processing is completed in the next step S710. That is, the counter i and the branch vector Vb _i If the number Nm is equal, the arrangement of the vertices 104a1 of the Nl leaf polygons 104a has been determined, so the processing shown in FIG. If i and Nm are different (if i is smaller than Nm), the process returns to step S703 to perform the next process.
[0198]
When the arrangement of the leaf polygon 104a is determined, step S202 in FIG. 11 is completed.
[0199]
Next, the process proceeds to the process of determining the leaf orientation shown in FIGS. Since these processes are the same as those in the fourth embodiment, a detailed description thereof will be omitted.
[0200]
Further, after the process of determining the leaf orientation is completed, the process may be performed in the same manner as in the first embodiment.
[0201]
Although the branch vector has been described by exemplifying a part actually drawn as a part of the trunk 102, in order to display only the leaf at a part where no branch exists, the branch vector Vb is displayed at a fictitious position. _i May be set.
[0202]
As described above, in the image drawing method according to the sixth embodiment, the branch vector Vb is applied to the trunk 102. _i Since the leaves are arranged on the branch vector, the image creator can determine the number of leaves Nl and the branch vector Vb. _i Therefore, normal modeling work is not necessary, and each leaf is arranged on a branch, so that an atmosphere closer to an actual plant can be expressed.
[0203]
In the above description, the drawing of leaves has been described, but the present invention may be applied to other forms such as drawing of a group of animals in addition to drawing of leaves.
[0204]
It should be noted that the present invention Painting The image drawing device, the recording medium, and the program are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.
[0205]
【The invention's effect】
As described above, the present invention relates to Painting According to the image drawing apparatus, the recording medium, and the program, the polygon surface is rotated so that the normal line of the predetermined polygon surface faces a predetermined direction.
[0206]
For this reason, the effect that the polygon of the direction which is inconvenient on drawing can be corrected is achieved.
[Brief description of the drawings]
FIG. 1 is a hardware configuration diagram according to the present embodiment.
FIG. 2 is a configuration diagram of an electric circuit according to the present embodiment.
FIG. 3 is an explanatory diagram of analog input values obtained by left and right joysticks.
FIG. 4 is a diagram illustrating a leaf polygon.
FIG. 5 is a diagram illustrating an example in which a trunk object and a large number of leaf objects are drawn.
6A is a ZX plan view of the virtual space, FIG. 6B is an enlarged view of FIG. 6A, and FIG. 6C is a ZY plan view of the virtual space.
FIG. 7 is a flowchart of a tree drawing process.
FIG. 8 is a diagram illustrating an object information table.
FIG. 9 is a diagram showing a stem polygon information table;
FIG. 10 is a flowchart of trunk drawing processing;
FIG. 11 is a flowchart of leaf drawing processing;
FIG. 12 is a flowchart for determining the orientation of leaves according to the first embodiment.
FIG. 13 is a diagram illustrating a leaf polygon information table;
FIG. 14A is a diagram illustrating a first rotation process according to the first embodiment, and FIG. 14B is a diagram illustrating a second rotation process according to the first embodiment.
FIG. 15 is a flowchart (part 1) illustrating a flow of selecting a processing method for determining a leaf direction;
FIG. 16 is a flowchart (part 2) showing a flow of selecting a processing method for determining the leaf direction;
17A is a ZX plan view of a virtual space according to the second embodiment, and FIG. 17B is an enlarged view of FIG. 17A.
FIG. 18 is a diagram illustrating a rotation process according to the second embodiment.
FIG. 19 is a diagram for explaining vectors in the rotation processing according to the third embodiment.
FIG. 20 is a flowchart for determining the placement of leaves according to the fourth embodiment.
FIG. 21 is a view for explaining a leaf drawing range according to the fourth embodiment;
FIG. 22 is a flowchart for determining the arrangement of leaves according to the fifth embodiment.
FIG. 23A is a diagram illustrating a function for determining the X-axis component of the leaf arrangement according to the fifth embodiment, and FIG. 23B is a Y-axis component of the leaf arrangement according to the fifth embodiment; FIG. 23C is a diagram illustrating a function for determining the Z-axis component of the leaf arrangement according to the fifth embodiment.
FIG. 24 is a flowchart for determining the arrangement of leaves according to the sixth embodiment.
FIG. 25 is a diagram showing a branch vector information table.
FIG. 26 is a diagram illustrating a branch vector.
FIG. 27 is a diagram illustrating a branch vector.
[Explanation of symbols]
100 ... virtual space 102 ... trunk
104a ... Leaf polygon
104a1 to 104a4 ... vertex of leaf polygon
e ... Virtual viewpoint f, g, h ... Function
V ... Normal vector of polygon surface Vb _i … Branch vector
Z0: Screen surface

Claims (8)

In an image drawing apparatus in which a display device for displaying an image is connectable and a CPU for executing various programs is built-in,
The program is
A coordinate system in the virtual space where objects and polygons are placed.
Means for rotating at least one polygon by predetermined means;
Means for resetting the orientation of the polygonal surface when the angle formed by the direction of the reference virtual viewpoint for drawing the image and the direction of the normal of the surface of the rotated polygon is 90 ° ± a °;
An image drawing apparatus characterized by functioning. The image drawing apparatus according to claim 1.
The polygon image drawing apparatus, characterized in that the image including the leaves or branches of the plant. The image drawing apparatus according to claim 1 or 2,
The image drawing apparatus characterized in that the predetermined means is a random number generating means, and the polygon is rotated in a direction set from the random number obtained by the random number starting means . The image drawing apparatus according to any one of claims 1 to 3 ,
The image drawing apparatus , wherein the polygon is a rectangle or a square. In the image drawing device according to any one of claims 1 to 4 ,
The image drawing apparatus characterized in that the information about the polygon includes position information data of at least one vertex among all the vertices of the polygon. The image drawing apparatus according to claim 5 .
The means for rotating the polygon performs a rotation calculation on the position information data of the at least one vertex to obtain a converted position after the rotation, and obtains the other vertex by converting from the converted position. An image drawing apparatus . In a recording medium in which a display device for displaying an image is connectable, and a program and data used in an image drawing device including a CPU for executing various programs are recorded and readable by the CPU,
The program is
A coordinate system in the virtual space where objects and polygons are placed.
Means for rotating at least one polygon by predetermined means;
Means for resetting the orientation of the polygonal surface when the angle formed by the direction of the reference virtual viewpoint for drawing the image and the direction of the normal of the surface of the rotated polygon is 90 ° ± a °;
A recording medium that functions as a recording medium. In a program that can be connected to a display device for displaying an image, is used in an image drawing device with a built-in CPU that executes various programs, and can be read and executed by a computer,
A coordinate system in the virtual space where objects and polygons are placed.
Means for rotating at least one polygon by predetermined means;
Means for resetting the orientation of the polygonal surface when the angle formed by the direction of the reference virtual viewpoint for drawing the image and the direction of the normal of the surface of the rotated polygon is 90 ° ± a °;
A program characterized by functioning.

Images