JPH05303646A - Method and device for generating texture - Google Patents

Abstract

PURPOSE:To make a video display inherent in a wide area of configuration of ground by means of the smaller memory capacity and a calculation circuit by separating a memory which stores patterns inherent in the configuration of ground according to the degree of detail and taking the same configuration in spite of the difference of the configuration of ground. CONSTITUTION:In a modulator section 5 inherent in configuration of ground, the texture inherent in the configuration of ground where polygonal surface is formed and having the hierarchical resolution according to the distance from the view point to the topographical surface is stored in a plurality of memories. An address calculation section 3 calculates the address specifying the location in the area which can be seen most clearly from among the hierarchical area. A pattern address calculation section 4 calculate the address of the general texture in the present area according to the present view point corresponding to the location of the calculation object of the address calculation section 3 and calculates the level of the degree of detail of the general texture which can be seen from the view point. Thus the memory content corresponding to the hierarchical area can be read out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a texture generating method and a texture generating apparatus used in a digital image generating apparatus, and a pattern created from a photograph or the like is electronically attached to a polygon without increasing the number of polygons. The combined display image can be shown realistically, and it is used to generate an out-of-window visual field simulation image for various training devices such as flight simulators.

[0002]

2. Description of the Related Art In a digital image generating apparatus, an object forming a field of view is formed by a polygon (polygon), and various patterns (textures) are attached to the polygon in order to enhance a sense of reality.

FIG. 2 shows a block diagram of a conventional digital image generating apparatus. In FIG. 2, the view calculation device 21 stores a plurality of scene data in an external storage device, and according to a command sent via a host computer (not shown), for example, selection of a training area, weather conditions, etc. Is set. That is, the model data is selected and transferred to the geometric calculation device 22, the color table, the fade
Tables such as tables and texture patterns are loaded into the video signal processing device 23. In addition, the coordinate transformation matrix from the database coordinates to the screen coordinates is calculated according to the position and attitude of the own aircraft (viewpoint) which is calculated and sent from the host computer every moment, and the projective geometry of the geometric calculation device 22 is calculated. Control the calculation. Further, the field-of-view calculation device 21 is also used for offline creation and modification of the database.

In the geometrical calculation device 22, a screen calculation circuit (not shown) therein selects a display object within the field of view, calculates a priority order for hidden surface removal for those objects, and configures polygons or polygons. Calculation of brightness of vertices, conversion of polygons forming an object to screen coordinates, clipping, perspective conversion, etc. Further, from the above calculation result obtained by the screen calculation circuit obtained as a set of edges (each side of the polygon), processing such as calculation of change rates of brightness and fade in the scanning line direction is performed. further,
The screen calculation circuit (not shown) performs coordinate conversion, perspective conversion, calculation of intersection brightness, etc. for the light spots having priorities, and outputs the light spots to the video signal processing device 23 together with the priority. Further, the geometric calculation device 22 calculates parameters such as coordinate conversion for mapping the texture into polygons, and transfers the parameters to the video signal processing device 23. Furthermore, the distance from the designated position to the object surface in an arbitrary direction is calculated.

The video signal processing device 23, which generates a video signal, calculates the color and brightness of each pixel of a polygon forming an object, and performs the concealment process of the polygon and the light spot. Shading, texture mapping, fading, spot lighting, and edge smoothing are performed in the calculation of pixel color and brightness.
The calculation result is D / A converted and displayed together with the synchronization signal on the display device 2.
4, output to a CRT, for example.

Conventionally, when it is desired to display the texture peculiar to the terrain over a wide area in detail, the memory for preliminarily storing the texture pattern created by using a plurality of aerial photographs or the like becomes huge, and the terrain of the terrain is enlarged. Due to the resolution of the texture, at a low altitude (relative distance between the viewpoint and the target terrain), the texture is tiled (the pattern is originally different for each pixel, but due to the limit of resolution, it becomes the same pattern over a wide pixel. There was a problem such as a phenomenon that a striped pattern was pasted), which significantly impairs the realism of the image.

[0007]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to generate texture peculiar to a terrain over a wide area without significantly increasing the memory capacity, to prevent the texture tiling phenomenon, and to further improve the general purpose. It is to make it possible to easily synthesize a texture.

[0008]

In the texture generating method according to the present invention, since a texture is attached to a polygonal surface which constitutes a three-dimensional scene assumed to be seen from a moving viewpoint, the polygonal surface is Textures that are peculiar to the terrain to be formed and that have hierarchical resolution according to the distance from the viewpoint to the terrain surface are stored in advance in multiple memories, and the texture according to the distance from the viewpoint to the terrain surface is stored in the memory. Is read from.

The texture generating device is a device for applying a texture on a polygonal surface which constitutes a three-dimensional scene assumed to be viewed from a moving viewpoint, and the distance from the viewpoint to the topographic surface. The area that can be seen according to the above is hierarchized, and the address calculation unit that calculates the address that specifies the position in the layered area that is closest to the viewpoint and the address calculated by the address calculation unit Correspondingly, according to the distance from the viewpoint to the terrain surface, the pattern / address calculator that calculates the address and level of detail of general-purpose texture that is not unique to the terrain in the area currently being viewed, and the terrain formed by the polygonal surface In addition to having multiple memories that store in advance textures that are hierarchical to the terrain surface from the viewpoint and are unique to A terrain-specific modulator that generates an address based on the address calculated by the address calculator, the address calculated by the pattern / address calculator, and the level of detail and reads the contents of the memory, and the terrain from the terrain-specific modulator. It is equipped with a generic modulator unit that combines a general-purpose texture of the terrain with a unique texture.

[0010]

The texture peculiar to the terrain formed by the polygonal surface is stored in advance in a plurality of memories as having a hierarchical resolution according to the distance from the viewpoint to the terrain surface, and is provided in the terrain peculiar modulator unit. Be done. By doing so, it is possible to prepare a texture unique to the terrain over a wide area without increasing the memory capacity. This is read by generating an address from the address from the address calculator, the address from the pattern / address calculator, and the level of detail. The address calculation unit calculates the address that specifies the position in the area that looks the most detailed among the layered areas (the layered area that is closest to the point of view), and the pattern address calculation unit , The address of the general-purpose texture in the area currently being viewed is calculated in accordance with the position of the calculation target of the address calculation unit, and the general-purpose texture of the general-purpose texture visible from the position of the viewpoint is calculated. The level of detail is calculated. By calculating the address in this way, the memory content corresponding to the hierarchical area can be read. The read texture unique to the terrain can be combined with a general-purpose texture to realize various arbitrary scenes.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 3, a memory composed of area blocks of 5 × 5 blocks surrounding the viewpoint is shown, and one block is 25
It consists of texels with a capacity of 6 × 256 and a depth of 24 bits (8 bits for each of R, G, and B).

A texture peculiar to the terrain created from aerial photographs and the like is stored in advance in this area block. If the resolution of the texture is 2 m / texel, one side is 2
56 × 2m × 5BLOCK = 2,560m, which means that the area block shown in FIG. 3 has secured an area of about 2.6km square.

FIG. 4 (a) is a schematic diagram showing that the coverage area becomes wider by using a plurality of area blocks having the same structure as FIG. 3, and FIG. 4 (b) illustrates a memory plane for storing the area blocks. FIG. For example, the resolution of the texture stored in the first area block 41 is 2 m /
If texels are used and the texture to be stored in the second area block 42 is 4 m / texel, the area covered by the two is 5,120 m square, of which 2,560 m square is the detailed texture and the rest is Filled with a texture with half the detail. The two area blocks 41 and 42 are memory planes having the same capacity as shown in FIG. 4B, and the total memory requirement is the number of texels in one block = 256 × 256, 1 texel. Number of bytes = 3 bytes, number of blocks in one area = 5 x 5 = 2
5, the number of memory planes = 2, 256 × 256 ×
It is 3 × 25 × 2 bytes. First area block 41
Indicates that the distance from the viewpoint to the topographic surface is short, and the second area block 42 corresponds to the case where the distance is relatively far. In this way, each information having a hierarchical resolution according to the distance from the viewpoint to the topographic surface is stored in the memory. By the way, if the same area is to be secured by the conventional method, four memory planes of the same capacity are required, which is 256 × 2.
It is 56 x 3 x 25 x 4 bytes, which requires double.

If seven layers of area blocks are prepared in this way, the area covered will be 164 km square, and the memory will be 7/2 ^{(7-1) 2} ≅1 / 585 as compared with the conventional method. This effect increases as the coverage area increases.

FIG. 5 shows the relationship between the detail level of the texture stored in the area block and the area block. As shown in the figure, one block B with the level of detail i covers four blocks in the area covered by one block A with the level of detail i-1, and the texture at the level of detail i has the level of detail i-1. Has half the resolution of the case. When creating a texture unique to the terrain, a pattern file corresponding to the level of detail is created independently, and the absolute position on the earth (LAT.LONG) and the level of detail are used in the file name to load the file corresponding to the viewpoint. It makes it easy to find the texture that should be used.

FIG. 6 is a schematic diagram for explaining a method of calculating a memory address in which the texture unique to the terrain is stored when the terrain data (polygon) is divided into blocks according to the texture unique to the terrain. .. It is assumed that the point of view EYE is in the block A with the desired movement, and the point Q on the polygon in the block B viewed through the screen S from that point is vertically projected on the horizontal plane Q '.

The normalized memory address << m >> is obtained by the calculation of the equation (1). Note that, for example, << m >> means a vector of size m, and in the following description, the vector notation will be used in both cases of <<>> and thick case.

[0018]

[Equation 1]

The calculation in the texture generating device is given by the equation (2) if it is divided into a part to be calculated in frame units and a part to be calculated in pixel units.

[0020]

[Equation 2]

Further, << r _O >>, << r _x >>, and << r _y >> are mapping parameters which define how to paste the texture (direction, size) on the polygon as shown in FIG. 7, for example. It can be specified by the user before operation. Moreover, in FIG. 6, in the case of a pattern unique to the terrain,

[0022]

[Equation 3]

It is

<< r _T >> is the distance from the origin of the surface forming the polygon to a point on the surface

<< r _RE >> is the viewpoint position seen from the origin of the block

_<< r _pq >> is a vector from the viewpoint to the point Q where the straight line connecting the viewpoint and the pixel (p, q) intersects the polygon.

H is a transformation matrix from the viewpoint coordinate system to the block coordinate system

ZI _pq is the reciprocal of the Z value of the point Q.

<< P >> is a vector [p, q, 1] ^t

These are respectively shown.

FIGS. 8 (a) and 8 (b) show the relationship between the area blocks having different levels of detail and the memory address calculation. Only the memory address of the area block at the level of detail-0 is described above. The calculation shown in the equation (2) is performed, and for other details, it is shown that the address can be calculated by shifting and extracting.

It is assumed that the block address of the area block of the level of detail level-0 to which the point Q'belongs is (k _O , l _O ) and the intra-block address is (m _O , m _O ). At this time, Q ′ is the block address (k _i , l _i ) and the intra-block address (m _i , n _i ) as in Expression (3) at the level of detail level −i. However, the address in the block is a normalized address.

[0033]

[Equation 4]

This calculation is performed by shifting and extracting as shown in FIG. 8 (b).

FIG. 1 is a block diagram of an embodiment of the texture generator. The texture generator 91 of FIG. 1 is provided in the video signal processor 90 of the digital image generator as shown in FIG. 9, and is connected between the face buffer 92 and the video mix 93. As shown in FIG. 1, the texture generating device 91 includes a dynamic texture memory unit 1, a texture code table unit 2,
An address calculation unit 3, a pattern address calculation unit 4, a terrain-specific modulator unit 5, and a generic modulator unit 6 are provided.

The inputs to the device are C _T , _<< C _Fpq >>, (p,
q), ZI _pq , << T _X >>, << T _Y >>, << T _O >>, BLKI
D (k _O , l _O ), DZI _p and DZI _q, which are sent from a geometrical computing device (not shown). The output of the device is F
_pq , _<< C _pq >>, T _pq , M _pq , which are used in the video mix 93 of FIG. These inputs and outputs have the following meanings.

C _T : Number representing the type of texture to be given to the polygon

_<< C _Fpq >>: Color of polygon (R, G, B)

P, q: CRT pixel position (p is pixel, q is scan line direction)

ZI _pq : Reciprocal number of the Z coordinate value of the point where the line connecting the viewpoint and the pixel position (p, q) intersects the polygon.

<< T _O >>: Geometric calculation device (G
Mapping parameter sent from P) that determines the memory address of the area block (parallel movement part)

<< T _x >>: Geometric calculation device (G
Mapping parameter (X direction) that determines the memory address of the area block sent from P)

<< T _Y >>: Geometric calculation device (G
Mapping parameter (Y direction) that determines the memory address of the area block sent from P)

BLKID (k _O , l _O ): Level of detail-
Block number (block address) in area block 0

DZI _p : Z- ¹ change rate in the p direction of the corresponding polygon

DZI _q : Z- ¹ change rate in the q direction of the corresponding polygon

F _pq : Indicates whether the output data T _pq and M _pq are valid / invalid

_<< C _pq >>: Color of pixel to be added to pq position

T _pq : Transparency of pixel to be given at pq position

M _pq : mask value at pq position

FIG. 10 shows a detailed view of the essential parts of the terrain-specific module section 5, and FIG. 11 shows a detailed view of the essential parts of the generic modulator section 6. The operation will be described below with reference to FIGS. 1, 10 and 11.

The dynamic texture memory unit 1 is a generic texture (general-purpose texture of terrain).
Is a memory that holds information for apparently moving the pattern. It is sent from a view calculation device (VCP) not shown, and sent via a geometric calculation device (GP) not shown. By changing dx _i and dy _i for each frame, it is possible to give a complicated motion to the pattern.

The texture code table section 2 stores information for moving the texture generator as defined by the user, and is a table corresponding to the code texture CT. This code / texture CT number is used, for example, to identify the pattern to be given to each polygon as shown in FIG. Each element of the table is log ₂ R _i ,
_{R i, SLCT1, SLCT2, SLCT3} , SLCT
4, << C ₁ >>, << C ₂ >>, << C ₃ >>, F, a _i (i = 1 ...
9) and has the following meanings.

R _i : The size L _{i of the} pattern i with respect to the basic size (defined by << r _x >> or << r _y >>) for defining the sizes of the nine patterns (basic patterns) in the generic modulator unit 6. The ratio | << r _x >> | / L _i .

Log ₂ R _i : a constant used in determining the detail level of each pattern

SLCT1: Selection information for controlling the gate 61 of the generic modulator section 6, that is, a color which is an input to the generic modulator section 6 and which is calculated and input by the terrain-specific modulator section 5 (r, g,
information for selecting "C _GS", "C _FPQ" as a color given to the object surface (r, g, b) in pq point, or "0" as b)

SLCT2: Defines which color mixer section 621, 622 or 623 in the generic modulator section 6 the modulation value (<< C _pq >>) is output as the modulation value or transparency (T _pq ).

SLCT3: Designation as to whether or not one bit is extracted from the 8-bit information stored in the memory blocks 631 to 633 in the generic modulator unit 6 and used as a mask value (corresponding to pattern)

SLCT4: Designation of which of the memory blocks 631 to 633 in the generic modulator unit 6 is to be assigned to the corresponding pattern

<< C ₁ >>, << C ₂ >>, << C ₃ >>: Colors R, G, B used for color mixing

A _i : Designate the contribution rate to the modulation value of each pattern stored in the memory blocks 631, 632, 633 with a general pattern not specific to the terrain, and amplifying parts (× a ₁ , × a) ₂ , ... × a ₇ ) 641,64
2, ... 647 respectively.

F: transparency T _pq , mask value M _pq valid / invalid, 0: _<< C _pq >> output, 1: _<< C _pq >>, T _pq ,
2: _<< C _pq >>, M _pq

Address calculation unit 3: mapping parameters << T _O >>, << T _X >>, sent from the geometric calculation unit,
The calculation for the next pixel is performed using _<< T _Y >>, and the address << m >> in the area block of the detail level −0 is calculated by the equation (4).
Ask by. Note that p, q and ZI _pq are video signal processing devices (V
It will be sent from P).

[0064]

[Equation 5]

Pattern / address calculation unit 4: next a, b
Calculate.

A. Memory address calculation for each pattern

Expression (5) is calculated by using the intra-block address << m >> of the area block having the detail level -0 to obtain the address << M _i >> of each pattern in the generic modulator unit 6.

[0068]

[Equation 6]

B. Calculation of level of detail L

The detail level L is calculated as in equation (6) (using << m >>), and the detail level L _i of each pattern is calculated as in equation (7) using this L.

[0071]

[Equation 7]

L _i = L + log ₂ R _i (7)

Terrain-specific modulator section 5: a section for generating a pattern unique to the terrain. As shown in FIG. 10, as described above, the memory / address calculator 51 determines the pattern unique to the terrain according to the distance from the viewpoint to the terrain surface (FIGS. 4 and 5).
An active texture memory (ACTIVE TEXTURE MEMORY) 52 and a level mix section 53, which store hierarchized and high-resolution ones, are stored. Level of detail obtained with the pattern address calculation unit 4 (FIG. 1) L, the address of each pattern _{"M (M x, M y} )", and level of detail -0
Block number BLKID in the area block
(K _O, l _O) becomes L _L ≦ L ≦ L _H by calculation of equation (8) in the memory address calculation unit 51 with reference to, determine the L _L and L _H.

[0074]

[Equation 8]

L _L and L _H are used to determine two area blocks or active texture memory 52. The corresponding block numbers (kL _L , lL _L ), (kL _H , lL _H ) and in-block memory addresses (mL _L , nL _L ), (mL _H , nL) according to the equation (3) described with reference to FIG. _H )
Ask for.

[0076] _{(L L, kL L, lL} L, mL L, nL L) and _{(L H, kL H, lL} H, mL H, nL H) content of each memory as an address "CL _L", " CL _H >> is taken out. In the level mix unit 53, << CL _L >> and << CL _H >> are mixed by the decimal part of L as shown in Expression (9) to correct the discontinuity on the image display of the pattern due to the layering.

<< C _GS >> = (1-α) << CL _L >> + α << CL _H >> (9)

However, α is a fractional part of L

This color << C _GS >> is output to the generic modulator section 6.

Generic modulator part 6: Basically, Japanese Patent Laid-Open No. 63-186375 previously disclosed by the applicant of the present application.
The operation described in the publication, entitled "Color Mixing Method in Pattern Generation", is performed. This is a part that generates a complex and versatile pattern by using a small number of basic patterns (including a mask pattern) and changing the size and intensity of the basic pattern to combine them. Texture code table section 2 specified by number
A predetermined operation is performed according to the contents of. The following functions can be realized as the types of modulation.

(A) Full-color texture: By setting the modulation value in the video mix 93 of FIG. 9 to 1, it is possible to realize a full-color texture in which the same colors and patterns as those of a photograph are attached to polygons.

(B) Intensity modulation texture

(C) Color blending texture;

(D) Trans-lucency modulation texture; for a pattern such as cloud or fog whose contour is unclear, as shown in FIG. 13, for example, transparency T _pq and cloud color _<< C _pq >> of a part having a cloud shape. Outputs the modulation values so that and combine in the video mix 93 of FIG. This can be specified by the user.

(E) Contour texture;
This is a technique for obtaining a pattern of a tree or the like by combining the contour of the tree and the pattern of the leaves in the video mix 93 of FIG. 9 as shown in FIG.
(Depth of bit) One bit is used for contour, and user can specify whether to use or not to use.

The above-mentioned functions are performed by the pattern values stored in the memory blocks 631 to 633 of the generic modulator 6 and the S in the texture code table unit 2.
LCT1, SLCT2, SLCT3, SLCT4, << C
_{1 "," C 2 ",} " C 3 ", carried out by combining appropriately the a _i.

As described above, the memory blocks 631 to 631
Reference numeral 633 is a memory having 256 × 256 texels and a depth of 8 bits, in which a basic pattern is stored. Of these 8 bits, 1 bit is called a mask pattern and the remaining 7 bits are called a modulation pattern. The mask pattern represents an outline, and the modulation pattern is a general-purpose pattern that is not specific to the terrain. Memory blocks 631, 632, 633
_Are addressed by the level of detail L _i of each pattern and the addresses M _xi , M _{yi obtained} by the pattern / address calculator 4 (FIG. 1). The SLCT 4 then outputs the BLO of the addressed memory block 631, 632, 633.
It is used to select which of CK1 to CK4 is used as pattern information. FIG. 15 shows an example in which SLCT4 specifies to use BLK3 of a certain memory block 63 as a pattern P _i . The selected basic pattern of BLK3 passes through the level mixing unit 65 and the amplification unit 64, and is combined with other basic pattern patterns by the pattern addition unit (Σ) 66 (661, 662, 663) and the first selector 67. Output to.

In the first selector 67, each pattern adder 661, 662, as shown in FIG.
Outputs M1, M2, M3 of 663 and outputs M × 1, M × 2, ... M of color mixers 621, 622, 623 for defining colors
Correspondence with x9 is designated. Since this selection is possible, the basic patterns can be mixed with a high degree of freedom (a complicated texture can be easily generated with a small number of basic patterns).

The second selector 68 is instructed by the SLCT 3 to select whether to use the mask information among the basic patterns stored in the memory blocks 631 to 633. SL of 9-bit information as shown in FIG.
The logical product (AND) of CT3 and each mask bit is output. This allows the mask used for the mask to be selected.

The gate 61 receives the SLCT1 and receives the signal shown in FIG.
The surface color _<< C _Fpq >> is set to _<< C _>> , or _<< C
_GST >> is set as _<< C >> or << 0 >> is set as << C >>. Here, _<< C _Fpq >> is (r, g, b), and _<< 0 >> is (r = 0, g = 0, b = 0). Functionally, in the case of (a), it is shown that the pattern of the generic texture is added as the basic color of the polygon, and in the case of (b), the pattern unique to the terrain from the terrain specific modulator unit 5 is shown. It shows that the pattern of generic texture is superimposed on the texture of. In the case of (c), generic textures (<< C1 >>, << C2 >>,
<< C3 >>) alone indicates that the color is independently determined.

[0091]

As described above, according to the present invention, the memory for storing the pattern unique to the terrain is separated according to the degree of detail,
At this time, by making the memory configuration the same regardless of the difference in details, it is possible to display an image peculiar to a wide area topography with a small memory capacity and a small calculation circuit. Further, by superimposing a plurality of general-purpose patterns having a scale different from the pattern unique to the terrain, it is possible to generate an image having a wide dynamic range, that is, a tile phenomenon is less likely to occur, and the reality of the image is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a texture generation device according to the present invention.

FIG. 2 is a block diagram showing a conventional digital image generating device.

FIG. 3 is a diagram illustrating an area block that constitutes a memory.

FIG. 4 is a diagram illustrating that the coverage area is widened by a plurality of memories.

FIG. 5 is a diagram showing a relationship between a detail level of a texture stored in an area block and the area block.

FIG. 6 is a schematic diagram for explaining a method of calculating a memory address in which a pattern unique to the terrain is stored when the terrain data (polygon) is divided into blocks according to the pattern unique to the terrain.

FIG. 7 is a diagram illustrating a state in which a texture is attached to a polygon.

FIG. 8 is a diagram showing a relationship between area blocks having different degrees of detail and memory address calculation.

FIG. 9 is a diagram showing a relationship between a texture generation device and a video signal processing device.

FIG. 10 is a block diagram of a main part of a terrain-specific module unit.

FIG. 11 is a block diagram of a main part of a generic modulator unit.

FIG. 12 is a diagram for explaining code / text numbers.

[Fig.13] Trans-lucency modulation
It is a figure explaining a texture.

FIG. 14 is a diagram illustrating contour texture.

FIG. 15 is a diagram illustrating the operation of SLCT4 in a memory block.

FIG. 16 is a diagram illustrating an operation of SLCT2 in the first selector.

FIG. 17 is a diagram for explaining the operation of SLCT3 in the second selector.

FIG. 18 is a diagram for explaining the action of SLCT1 at the gate.

[Explanation of symbols]

 1 dynamic texture memory unit 2 texture code table unit 3 address calculation unit 4 pattern address calculation unit 5 terrain specific modulator unit 6 generic modulator unit 52 active texture memory 631, 632, 633 memory block

Claims (2)

[Claims] 1. A texture generation method for applying a texture to a polygonal surface which constitutes a three-dimensional scene, which is assumed to be viewed from a moving viewpoint, in a texture unique to the terrain formed by the polygonal surface. A plurality of memories having a hierarchical resolution according to the distance from the viewpoint to the topographical surface are stored in advance, and the texture corresponding to the distance from the viewpoint to the topographical surface is read from the memory. Texture generation method. 2. A texture generation device for applying texture to a polygonal surface which constitutes a three-dimensional scene assumed to be viewed from a moving viewpoint, the texture generating apparatus according to the distance from the viewpoint to the terrain surface. Areas that can be viewed are hierarchized, and the address calculation unit that calculates the address that specifies the position in the layered area that is closest to the viewpoint and the address that is calculated by the address calculation unit , A pattern / address calculator that calculates the address and level of detail of a general-purpose texture that is not unique to the terrain in the area currently being viewed according to the distance from the viewpoint to the terrain surface, and the terrain that is unique to the terrain formed by the polygonal surface In addition to having a plurality of memories for storing textures, which have a hierarchical resolution according to the distance from the viewpoint to the topographic surface, A terrain-specific modulator that generates an address from the address calculated by the calculator, the address calculated by the pattern address calculator, and the level of detail, and reads the contents of the memory; and a texture unique to the terrain from the terrain-specific modulator. On the other hand, a texture generator including a generic modulator unit that combines general-purpose textures of the terrain.