Hello.
This is another performance question topic 
ok question a : how much performance loss is it when i have 2 textures on an object instead of 1.
B : is it better to set variables in Start or can you set them in the script outside any functions (they will need to know the Screen.width).
Hmm i think i have forgotten something… but if i have i will post it in coming posts.
For each attached material (and for each pass in the shader) the objects geometry has to be rendered once.
So, one material is always faster than two. When using the same shader in 2 different materials on a single object, render time would logically be doubled.
that was bad i have to figure out an solution.
thanks for the help.
Updated question:
What is the most performance loss?
3 objects with 2 textures on each one and cube colliders on each one
or
1 objects (the 3 of them joined) and 2 textures on that and 1 mesh collider
???
My experience is collision primitive are faster and more dependable than mesh colliders.
You’re better off with one object, 1 texture which contains all 3 textures and appropriate shader to simulate all materials (watch Joachim’s talk on performance optimization) – and collision primitives
Cube < Sphere < capsule (Matthew feel free to correct me on that one)
Well.
My game will often only be built of cubes so there are 6 polys for that and then if join 3 objects (cubes) there will be 30 triangles or 13 (i think) polys (if polys always are rectangular).
And the next thing is that i can’t build my things in 1 texture because i have to tile them in x and y directions if i don’t want to have different textures for different objects (that would be lots of textures).