How efficient do You use your texture units

[Lars]

Hi

Some time ago all Graphiccards had 2 Texture Units (from Voodoo 2 to GeForce2) only the relatively new Radeon and the new GeForce3 have more.
Does anybody think of Cards with more then two texture units. For example a Situation, where you put 4 Textures on to an object (Base,light,detail,shadow). Do you implement all the posssible setups like :

1. 4 passes with 1 Tex Unit
2. 2 passes with 2 Tex Units
3. 1 pass with 4 Tex Units

And if you make some of the textures variable for the user, would you use the version 1 pass with 3 Tex Units if only three textures are used ?

This is just a question of interest, cause it costs some writing to get all the possibile combinations, and what about future cards which have 8 Tex Units ?

Is it worth it to think about all the possibilitys or is it just important to support single and doubletexturing, or maybe only doubletexturing?

Lars

[IsaackRasmussen]

What about a shader/material system... where a material(let's call it that) has a list over all it's sub textures.
if you then store maxTextureUnits, divide that with the total count of textures, howManyTimes.
Use a while() loop for howManyTimes, then another while() loop to set up all texture units and then draw the object.
just until no more textures is left.

You get me?

[holocaust]

Lars wrote


And if you make some of the textures variable for the user, would you use the version 1 pass with 3 Tex Units if only three textures are used ?


If you decide to allow user to modify some textures just decide to give him/her the full power of your texturing system. So there is no need to break your texturing system into mutliple user-related sub-systems.

About the texturing strategy : use the TMUs that are available (glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB, (GLint *)&nb_tmu)) then render the remaining stage with multi-passe(s).