Reduce draw calls

[Nmzik]

Hello!
I started to reduce draw calls in my game and first thing it's try to "collapse" all materials
But how to do it??
My building have 7 textures so it's 7 draw calls!!!
I checked epic citadel and it has 2/3 textures on one material!!
Another thing is texture atlas
Is anybody here use atlases???
How to do it???and how use in game?

[darthviper107]

Draw calls count the number of materials not the number of textures.

[JessieG]

Well you can use Linear interpolates to switch between different textures within a single material, but since your building has 7 materials already, that would involve using linear interpolates for way too many textures than a single material can handle. Your only options are to either break that building up into separate pieces so that the whole thing doesn't have to be rendered at once if only a part of it is in view, or change your UVs and textures to try to reduce the amount of textures needed for the object. 3 materials on one object is the highest I ever go, and even that is almost never needed anyway unless under very specific circumstances.