Texturing: When to use one huge map or two smaller maps

CognizanCe

For the best results and maximizing use of UV space,
When should two smaller maps (like 1024) be used or be EXPECTED to give better results instead of using a single big map (like 2048).

I don't want to spend the time texturing something on a 2k map, to find out textures look more crisp if I used two 1k maps.

Is there any rule or theory to follow so that i know which approach to take?

Ark

Using multiple textures will add more draw calls versus a single texture.

CognizanCe

Ark wrote: »

Using multiple textures will add more draw calls versus a single texture.

That's bad right?

mAlkAv!An

Multiple materials will add draw calls, but you can still use a single material with multiple textures.
Also 2x 1024² = 1024x2048; 4x 1024² = 2048²

Ark

CognizanCe wrote: »

That's bad right?

Well it's all about balance like everything else. Obviously, less is better.

Would the texture benefit from the extra pixels and does the piece warrent them?

Then again if your want tiling textures, your probably better of with separate textures. Some can then be batched or turned into atlus textures to save on drawcalls.

warby

Q: When to use one huge map or two smaller maps ?

A: use huge map (2048x2048 or 4k for next gen i suppose ...) if engine and target hardware support it otherwise use the largest texture size possible and put as much info/detail into it as you humanly can.

the only reason to ever use multiple texture sheets is if the material properties are fundamentally different for example:
you need some "opaque normal-mapped" stuff on your asset while other elements needs to be "additive/transparent".




... why ? because of drawcall overhead ---> bad performance !

ZacD

Also what counts as a draw call is depends on the game engine. If it's for a personal portfolio project, just keep draw calls in mind, but if you making something for a particular engine, you should really know what counts as a draw call and what your targets and limits are. Using 2 or 3 textures for an important character really isn't a big deal. But using a dozen different textures for a street corner isn't good.

CognizanCe

TY for all the input guys.