Texture mapping method and image processing apparatus

Claim 2

A method according to claim 1, characterized in that the Z values given to the two-dimensional texture coordinates to transform the texture data into three-dimensional texture data are Z values on a projection plane.

Claim 3

An image processing apparatus having coordinate transform means for performing coordinate transform into a display coordinate system on the basis of model information constituted by a polygon stored in a memory device, an arithmetic operation unit for obtaining a luminance gradient from luminances of vertices of the polygon, means for storing an arithmetic operation result from said arithmetic operation unit, a rendering unit for performing shading, texture mapping, and the like of the polygon from the arithmetic operation result, means for storing a rendering result from said rendering unit in a memory, and a display controller having a display function of reading out the rendering result from said memory and displaying the readout data in a size designated at designated display coordinates, wherein means for performing said texture mapping for the polygon on a three-dimensional space, comprising: means (12, 13, 14, S1) for virtually giving depth information Z to all vertices for two-dimensional texture coordinates; means (14, 15, S2 - S6) for giving the depth information to each vertex of texture data to define the texture data as a plane in a three-dimensional space and virtually arranging the texture data in a space (visual point coordinates) of the polygon; arithmetic operation means (14, 15, S7) for moving the polygon and the texture data to the same three-dimensional space, performing linear transform between each vertex of the polygon and a corresponding vertex of the texture data in the three-dimensional space to obtain identical sizes and identical coordinate values between the polygon and the texture data; and means (14, 15, S8 - S12) for, after the polygon and the texture data are transformed to be identical to each other, performing linear mapping of each pixel on the polygon using coefficients of the linear transform and the depth value Z of each pixel on the polygon, thereby obtaining coordinate values of corresponding texture data.

Claim 4

An apparatus according to claim 3, characterized in that the Z values given to the two-dimensional texture coordinates to transform the texture data into three-dimensional texture data are Z values on a projection plane.

Claim 5

An apparatus according to claim 3, characterized in that the Z value of each pixel of the polygon is calculated in accordance with a DDA.

Claim 6

An image processing method of performing a coordinate transform process of performing coordinate transform into a display coordinate system on the basis of model information constituted by a polygon stored in a memory device, an arithmetic operation process of obtaining a luminance gradient from luminance of vertices of the polygon, a process of storing an arithmetic operation result in the arithmetic operation process, a rendering process of performing shading, texture mapping, and the like of the polygon from the arithmetic operation result, a first storage process of storing a rendering result in the rendering process in a memory, and a display process of reading out the rendering result from said memory and displaying the readout data in a size designated at designated display coordinates, wherein said method of performing texture mapping for the polygon on a three-dimensional space comprises virtually giving a Z (depth information) value as "1" to vertex information for two-dimensional texture coordinates to define texture data as a plane on the three-dimensional space, virtually arranging the texture data on a polygon space (visual point coordinates), calculating coordinate transform coefficients such that normal directions coincide with each other between planes respectively formed by the polygon and the texture data, transforming each pixel using the transform coefficients, multiplying the Z value with each pixel, and linearly mapping the texture data using resultant coordinate values.