Terrain Splatmap Optimization - 4 Texture still true?

Questions & Answers
1

I’m looking at this
http://wiki.unity3d.com/index.php?title=Terrain_tutorial

in particular the part about limiting the number of textures that get painted onto a Terrain to 4; once over that, additional splatmap work is needed.

Just wanting to confirm if something has changed in Unity and whether that’s still true? The actual wording of the Terrain doc @ http://docs.unity3d.com/Documentation/Components/terrain-Textures.html

is a little different, instead of recommending a limit of four it says:

Note: Using an amount of textures in a multiple of four provides the greatest benefit for performance and storage of the Terrain alpha maps.

2

AFAIK you can have as many terrain textures as you want. The “multiple of 4” rule is because the weight of each texture is encoded into the RGBA channels of one or more control textures. So, if you have four textures the splat control map can be encoded into four channels of a single texture. By adding a fifth texture, however, you need to start using the R channel of a second control texture (in which case, you can add three more textures to the G,B,and A channels of that texture “for free”)