10. Texture mapping

Brock University
COSC 3P98 Computer Graphics
Instructor: Brian J. Ross

Texture mapping

Texture maps

Mapping 2D textures

OpenGL: Texture maps

OpenGL: specifying texture

glTexImage2D(GL_TEXTURE_2D, GLint level, GLint components, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid *pixels)

OpenGL: more texture control commands

glTexEnv{if}{v}(GL_TEXTURE_ENV, GLenum pname, TYPE param);

glTexParameter{if}{v}(GL_TEXTURE_2D, GLenum pname, TYPE param);

OpenGL: assigning texture coordinates

   glTexCoord2f(0.0, 0.0); glVertex3f(1.0, -1.0, 0.0);
   glTexCoord2f(0.0, 3.0); glVertex3f(1.0, 1.0, 0.0);
   glTexCoord2f(3.0, 3.0); glVertex3f(2.41, 1.0, -1.41);
   glTexCoord2f(3.0, 0.0); glVertex3f(2.41, -1.0, -1.41);

Procedural textures

3D texture mapping

eg. Code from Watt, Program 7.1, p. 248 :

wood_grain(u,v,w:real; var r,g,b:real);
   var radius, angle: real;

   radius := sqrt(u*u+v*v);
   if w=0 then angle := pi / 2
          else angle := arctan(u,w);
   /* arctan evaluates arctan(u,w), but uses ingo to return
      a value betwen 0 and 2*pi */
   radius := radius + 2*sin(20*angle+v/150);
   grain := round(radius) mod 60;
   if grain < 40 then
      r := R_LIGHT; g := G_LIGHT; b := B_LIGHT;
      r := R_DARK; g := G_DARK; b := B_DARK;

3D texture mapping

Some examples of turbulence (via Strata StudioPro 1.75 Macintosh)

Complex 3D textures: Daz3D Bryce

Example Bryce images: One Two. Three. Four.

Complex editor features (Bryce 1)


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COSC 3P98 Computer Graphics
Brock University
Dept of Computer Science
Copyright © 2016 Brian J. Ross (Except noted figures).
Last updated: November 29, 2016