multi texture problem.

If you want to "fade" from one texture to another, I think you want 3D textures.

Check the Game Programming Wiki (gpwiki.org) they have a nice article

indeed, what i want is very sample.
for example, i have a bomb exploded somewhere, i want to a texture on there.
how can i do it?

Are you already using multitexturing?

If it is, all that's required in your case is finding the correct TexCoords if you have a piece of geometry in the place where the bomb exploded.

Else, you will probably have to create a little quad in the area which is textured with the "explosion" texture. In this case multitexturing isn't required, but it'll require an extra pass for the explosion textured quad.

yes, now i save many quad for every explode.
because i do not want the explode disappear next frame.
so i want a better way.

i am interesting in that the 1st way you said.
how can i do it with multitexture?

Quote:

Original post by zny yes, now i save many quad for every explode. because i do not want the explode disappear next frame. so i want a better way. i am interesting in that the 1st way you said. how can i do it with multitexture?

From OpenGL 1.3, or earlier versions through the ARB_multitexture extension, you can use more than one "texture unit" for texturing. To use it, first check if your extension string contains "GL_ARB_multitexture". If it does, your hardware is guaranteed to have atleast 2 texture units.

The default texture unit selected is texture unit 0. Suppose you have a bound texture on texture unit 0, as usual. With multitexture, you may call:

glActiveTexture(GL_TEXTURE1); // this selects the new texture unit 1glBindTexture(GL_TEXTURE_2D, explosion_texture); // bind explosion textureglEnable(GL_TEXTURE_2D); // enable texturing (this state is maintained per texture unit)// ...// specifying texture coordinatesglMultiTexCoord2f(GL_TEXTURE0, 0.0, 0.0); // these are for your terrain textureglMultiTexCoord2f(GL_TEXTURE1, 2.0, 3.0); // these are for your explosion textureglVertex3f(...);

And that's it! There are plenty of tutorials on this subject on the internet, but unfortunately I couldn't find even one, so this short introduction above.

Hope this helps!

yeah, thanks very much!!what you said is right,it help me a lot.
but..... i don't konw how to say.

you know until a bullet is exploded, nobody knows the 2nd texture's position.
so the 2nd texture's position is not static.

what i said is right?

try http://spy.nodespace.net/ and check my terrain engine, it uses the design you want.

Multitexturing fading, so you have grass and cliffs and stuff

many thanks!

i have download the Stretch, but i can not find any cpp files or lib files,
could you tell me how did you do it?

yeah, i have found a sample method,

use glTexSubImage2D() can slove this problem easy,

and it works very good!

thanks so many people help me!