To bake or not to bake?

[Max Pitre]

Does it matter as far as LI? In some cases I don't want to bake the textures within my 3D program so I can change seperate textures in game but does a baked texture help in any other way other than making all the textures into one? Hopefully I explained that correctly.

[arton Rotaru]

The short answer is yes, the number of materials on a mesh can have an impact on the land impact.

The long answer is, it depends.

The Land Impact can vary with the amount of the in-game vertex count of the mesh.
Everywhere where you have material borders, the vertex count will increase because the vertices will be doubled along the material border. However, if you have the UVs split already at that material border, the vertices were doubled already from the UV split. Same with hard edges. If you have a hard edge at the material border, the vertices were doubled already. So a material border, or a UV split won't increase the in-game vertex count any further in that case.

What is better in regards to rendering performance is another story though. Preferable is as few materials on a mesh as possible. 1 mesh, 1 material. Because if you have multiple textures on a single mesh, the mesh will be treated as multiple meshes in the render pipeline. Hence, an increase in drawcalls along with state changes (if it's different textures on the mesh) will occur. Which will produce a lot of overhead, and slows down rendering.

[Chic Aeon]

Just wanted to state that BAKING doesn't necessarily put all textures into one map. Someone could easily make an item with say four materials --  EACH mapped to fit a texture plane (let's hope 512 or 256 ). Each material "could" take a separate texture -- just like putting on a separate texture on each side of a prim is possible.  Personally I try and get all my textures on one map, but we each work differently.  

 

 

So a material (in the 3D modeling sense) equals and opportunity to make inworld changes  (textures, specularity and normal, glow, transparency, tint etc).  That same four material  object could take only ONE texture and the materials added could be needed for other reasons (listed above) OR for changing colors or textures via a script.

 

The textures could certainly all be on one map either by baking with textures in a combined way or by baking an ambient map and then adding different textures to various parts of the map and using MULTIPLY in graphics software to bond the two together.  

 

This wasn't necessarily a comment to the OP, but I thought some folks might be confused by what was mentioned.

 

EDIT: And I guess I should add that baking a map  doesn't stop you from using regular (unbaked) textures inworld. You can slap a texture on a baked item easily. How successful that will be would be dependant on the quality of the mapping.  Again, so not my thing - the gal seduced by gorgeous textures, but certainly doable!