texture limit and activating texture

OpenGL OpenGL: Basic Coding
1

hi,

im currently using 8800GT, when i do this method to check my texture limit:

GLint texLim = 0;
glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &texLim);
cout<< texLim << " TEXTURE LIMIT " << std::endl;

i got a value 32. does it means i can only do 32 texture? how if i want to put more texture on it?

also im going to attach this textures to my shader. ussualy i did it by usgin glActivateTexture(GL_TEXTURE0 - GL_TEXTURE31)? can i simply put 0-31 instead of GL_TEXTURE enum so I can use a loop to activate it?

thanks in advance

2

i got a value 32. does it means i can only do 32 texture? how if i want to put more texture on it?

Then you can’t. How exactly do you plan to use 32 textures to render a single object?

can i simply put 0-31 instead of GL_TEXTURE enum so I can use a loop to activate it?

No, but you can do glActiveTexture(GL_TEXTURE0 + i) where i is the loop index.

3

well not a single object, but for the entire scene, when there is floor, 3 different chair, lots of magazines and cover, etc2. which is definitely more than 32. is it possible to do that?

ah ok gonna try that, thx for the info :slight_smile:

4

Sure, the limit means that you can combine up to 32 textures in a single draw call (think multitexturing). You can use as many textures as you want in separate draw calls.

5

Sure. You can use texture arrays. Each one only consumes a single shader sampler (i.e. texture unit), yet you can put a boatload of 2D textures in one of these things, each one a separate 2D texture slice of the 2D texture array.

Alternatively, you can use texture atlases (precursor to texture arrays), but then you have to deal with cross-map filtering issues…