Performance cost of double sided material: not visible in stats?

[anonymous_user_c94f194d]

Triangles are culled by backface and object culling. So if you have a sphere, typically, the forward-facing tris are rendered while the backfaced tris are not. But by making the sphere double-sided, now the engine is filling all the backfaced tris on the sphere, doubling the vertex rendering for that object. And it’s doing this even if one pixel of the sphere is in view (technically, the object bounds). Keep in mind modern GPUs can handle millions of polygons, so you won’t ever reach a situation where making a single material double-sided will have a real notable performance impact (unless you’re rendering translucency or exceptionally high-polycount objects).

This is not correct. Two sided or not the vertex and triangle count it exactly same. Backface culling is happening after vertex shader stage and only affect rasterization and pixel shading cost. On CPU side there is no difference. It’s just simple rasterizer state.