> Use one set of large mesh buffers per vertex attribute layout
> Problem: Index/vertex buffers have to be re-bound when the mesh changes. This adds overhead when encoding draws and when drawing. It also prevents some optimisations like being able to draw all objects for shadow mapping for a light in one draw.
> Solution(s): [...] Use an appropriate allocator like a port of Sebastian Aaltonen's offset allocator [https://github.com/sebbbi/OffsetAllocator] to manage allocation
Where the "port of Sebastian Aaltonen's offset allocator" is what got linked in this HN submission.
The goal is to start storing multiple meshes in the same vertex buffer/index buffer. (I already have a decent chunk of this code written in a branch.) This reduces binding overhead, but moreover it allows us to start using multidraw indirect where supported, which should reduce drawcall counts dramatically. I measured a 97% drawcall count reduction for the opaque pass on the Bistro test scene, for example. The benefits are even higher for shadow maps, because they use a single shader and so the drawcall count should drop to the single digits in most cases.
I've said it before, but if drawcall count is a problem in your game, you should complain to the engine vendor. On modern GPUs, there's no reason people should be manually optimizing for drawcall count in 2024. Game engines have the tools to make it a non-issue; they just need to use them.
CaptainOfCoit|1 year ago
> Use one set of large mesh buffers per vertex attribute layout
> Problem: Index/vertex buffers have to be re-bound when the mesh changes. This adds overhead when encoding draws and when drawing. It also prevents some optimisations like being able to draw all objects for shadow mapping for a light in one draw.
> Solution(s): [...] Use an appropriate allocator like a port of Sebastian Aaltonen's offset allocator [https://github.com/sebbbi/OffsetAllocator] to manage allocation
Where the "port of Sebastian Aaltonen's offset allocator" is what got linked in this HN submission.
pcwalton|1 year ago
I've said it before, but if drawcall count is a problem in your game, you should complain to the engine vendor. On modern GPUs, there's no reason people should be manually optimizing for drawcall count in 2024. Game engines have the tools to make it a non-issue; they just need to use them.