I first saw this on Serious Sam(first or second encounter... don`t remember). And now it`s fairly used in games like Unreal and the like. Basicly we have a diffuse map, a detail map, and a lightmap. After seeing what the env_combine funcs can do, I came up with the idea for that 1 texture unit->Base Map*Detail Map(actually I use the GL_INTERPOLATE_ARB, but can`t figure out where to best put the Detail Map) 2 texture unit->LightMap This is what I use for that stuff ->

//

         glActiveTextureARB(GL_TEXTURE0_ARB);
//

glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_COMBINE_ARB);
    glTexEnvi(GL_TEXTURE_ENV,GL_COMBINE_RGB_ARB,GL_INTERPOLATE_ARB);//

                                          // now setup Arg0

    glTexEnvi(GL_TEXTURE_ENV,GL_SOURCE0_RGB_ARB,GL_TEXTURE);
    glTexEnvi(GL_TEXTURE_ENV,GL_OPERAND0_RGB_ARB,GL_SRC_ALPHA);
                                          // now setup Arg1

	glTexEnvi(GL_TEXTURE_ENV,GL_SOURCE1_RGB_ARB,GL_TEXTURE);
    glTexEnvi(GL_TEXTURE_ENV,GL_OPERAND1_RGB_ARB,GL_SRC_COLOR);

	glTexEnvi(GL_TEXTURE_ENV,GL_SOURCE2_RGB_ARB,GL_PREVIOUS);
    glTexEnvi(GL_TEXTURE_ENV,GL_OPERAND2_RGB_ARB,GL_SRC_COLOR);
//	

	glActiveTextureARB(GL_TEXTURE1_ARB);
//

	glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_COMBINE_ARB);
    glTexEnvi(GL_TEXTURE_ENV,GL_COMBINE_RGB_ARB,GL_MODULATE);
                                           // now setup Arg0

    glTexEnvi(GL_TEXTURE_ENV,GL_SOURCE0_RGB_ARB,GL_PREVIOUS);
    glTexEnvi(GL_TEXTURE_ENV,GL_OPERAND0_RGB_ARB,GL_SRC_COLOR);
                                          // now setup Arg1

	glTexEnvi(GL_TEXTURE_ENV,GL_SOURCE1_RGB_ARB,GL_TEXTURE);
    glTexEnvi(GL_TEXTURE_ENV,GL_OPERAND1_RGB_ARB,GL_SRC_COLOR);

My problem is-> If I`d normally use 3 texture units to make this stuff(and I wouldn`t bother anymore), everything would be just fine, but this way I won`t be able(or don`t know how to) scale the alpha map(which is the Detail Map), any help would be apreciated Edit:To clarify-> I mean I can`t use the

glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glScalef(size,size,size);
glMatrixMode(GL_MODELVIEW);

to show detail upclose [edited by - cippyboy on June 1, 2004 12:33:48 PM]

Try this and see if it works:

 glBindTexture(TextureID); glActiveTextureARB(GL_TEXTURE1_ARB); glEnable(GL_TEXTURE_2D); glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB); glTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 2); glBindTexture(DetailTextureID); glMatrixMode(GL_TEXTURE); glLoadIdentity(); glScalef(DetailLevel, DetailLevel, 1); glMatrixMode(GL_MODELVIEW);

Do you mean that you have the detail texture in the alpha channel of the diffuse texture?