🔒 Locked

Texture co-ordinate problem

Started by last-bastardo Jul 8, 2000 at 9:45 AM 1 reply 200+ views

Original Post

Jul 8, 2000 at 9:45 AM

If I have 2 traingles forming a square and want to texture a single texture map over those two triangles what are the texture co-ordinates I must employ. I have always texture mapped quads and never traingles so I don't see how you can specify three texture co-ordinates for a triangle when you need four. Please can somebody advise. -=Last Bastardo=- Edited by - last-bastardo on 7/8/00 10:24:15 AM

WitchLord

Mod

1,118

WitchLord

Jul 8, 2000 at 11:18 AM


(0,0)  (1,0)
  +-----+
  !\    !
  ! \   !
  !  \  !
  !   \ !
  !    \!
  +-----+
(0,1)  (1,1)

- WitchLord

Facehat

144

Facehat

Jul 8, 2000 at 11:21 AM

Just do it with triangle stripts, like so:

    
(in OpenGL code)

glBegin(GL_TRIANGLE_STRIP);

glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0f, 1.0f, -1.0f); //top left

glTexCoord2f(1.0f, 0.0f);
glVertex3f( 1.0f, 1.0f, -1.0f); //top right

glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0f,-1.0f, -1.0f); //bottom left

glTexCoord2f(0.0f, 1.0f);
glVertex3f( 1.0f,-1.0f, -1.0f); //bottom right


glEnd();

I haven''t used opengl in a while, so you might need to do a couple of things like switch the culling order.

BTW, you really should read up on this a bit more if you don''t understand it.

----------------------------------------
Whenever I see an old lady slip and fall on a wet sidewalk, my first instinct is to laugh. But then I think, what if I was an ant and she fell on me? Then it wouldn't seem quite so funny.

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.