Just let us know the result ya~
So I did some research today - starting with a blank scene:
- Static lighting (Static skylight and Static Directional Light)
- x1 ground mesh (1 material)
- x1 cube mesh (1 material)
- Both meshes share the same material
What I found was interesting - for some reason each mesh adds two draw calls to the scene, despite the fact they each have only one material. So 2 meshes = 4 draw calls. This is not as expected, especially with static lighting. Effectively, Unreal is currently doubling the amount of draw calls for each Static mesh for no reason from what I can see.
The same thing happens with Foliage instances; paint one mesh with one material x100 and you get x2 draw calls - not bad but certainly not as expected.
Anyone have any insight into this?!
We don’t know exactly what causes drawcalls, but I think that 1 drawcall comes from the indirect lighting cache.
Wow yeah that sounds basically exactly like what I’m getting. In fact using this math accounts for most of my draw calls. Why is it we dont know exactly what causes them?
UPDATE: the freaking BP_Sky_Sphere takes like 90 draw calls alone. I mean… what the hell?
^It takes 4 drawcalls at my end.
Seriously? Omg how could I have possibly screwed that up.
Just FYI, I posted about this on Answerhub also: https://answers.unrealengine.com/questions/594079/whats-going-on-with-my-draw-calls.html