Multiple textures on a polygon??

OpenGL OpenGL: Basic Coding
1

Hi!
How can you map 2 or more textures on a polygon?
My purpose is a “ground texture” with no transpareny and then a texture with half-transpareny mapped on the “ground texture” so that you cann still see the the groundtexture…
At the moment I´m doing this by drawing the polygon twice, but the performance is very bad because of the doubled polygons.
Thank you,
TheBlob

2

If you have multitexture support, you can use the GL_INTERPOLATE_EXT combiner that is part of the GL_COMBINE_EXT texture environment mode. That will let you combine two textures in that fashion.

3

As I understand you want multi-pass texturing. Just draw the surface twice with the two different textures with alpha blending enabled.

4

No, MrShoe, look again . He is already using multipass. He wants a single pass solution.

5

Im having the same prob.

i want a polygon with 2 texures and want to set the streght of each texture at the vertex. (or something like that)

i want a smooth fade from vertex to vertex and want it to fade from texture1 to texture2.

is it possible ? how ?

thanks…

6

Oh! A singlepass solution. Look on the following website, by zed.
He has an example of a single pass multi-texuring on his site. http://members.nbci.com/mybollux/