Just a Quick Texture problem

Graphics and GPU Programming Programming

Started by Marvin October 13, 2001 02:13 PM

3 comments, last by Marvin 22 years, 6 months ago

127

Author

October 13, 2001 02:13 PM

How do i stretch a texture over more than 1 polygon, eg have half on one polygon and half of the other, ive tried messing around with texture coordinates, do i have to play around with glTexParameter as well? Thanks

Lunatic Raven

122

October 13, 2001 02:21 PM

Well, its rather really simple. You need to mess with the Texture Coordinates.

And example could be this

Say you have two quads beside each other, and you want half of the texture to be on one, and have to be on the other, you would do this.

  glBegin(GL_QUADS);// Quad One, with half of the one textureglTexCoord2f(0, 0);glVertex3f(-1, -1, -5);glTexCoord2f(0.5, 0);glVertex3f(0, -1, -5);glTexCoord2f(0.5, 1);glVertex3f(0,  1, -5);glTexCoord2f(0, 1);glVertex3f(-1,  1, -5);// Quad Two, with half of the one textureglTexCoord2f(0.5, 0);glVertex3f(0, -1, -5);glTexCoord2f(1, 0);glVertex3f(1, -1, -5);glTexCoord2f(1, 1);glVertex3f(1,  1, -5);glTexCoord2f(0.5, 1);glVertex3f(0,  1, -5);glEnd();

"...."

Marvin

127

Author

October 13, 2001 02:34 PM

yes, thats just what i''ve been trying :/

maybe its because i want to tile the texture and have it repear, as in my other post at the mo if almost looks as if the texture''s being clamped.

Marvin

127

Author

October 13, 2001 02:48 PM

Ok heres the actual problem..

as you may see in the picture bellow, the texture isnt stretched at all, i need it stretched accross the poly's where the line is.

The picture bellow is using the texture coordinate system explained above.

Any ideas? it looks like clamping but clamping is off

if it helps im using Vertex Arrays and MultiTexturing

Thanks