Community Challenge: Explosions! đŸ’„

Announcements
#41

Nice! What doesn’t feel right? :thinking:

#42

Perf. Seems off. This is 256x256 (maximum compute cores I can run I think) and so its only 65K particles. And quite a small texture (in real terms). I think it should be possible to do much more than this. Going to look at multi-dispatches and see if that helps. Not now, but prob in a few weeks time.

#43

Maybe I can take a look at the performance and see if I can find anything. I’ll let you know

#44

The low performance isn’t because of the compute shader, it’s because of this loop happening in your “particle” shader:

image
image978×314 32.3 KB

That shader takes up something like 99.9% of the performance when I profile it in xcode :slight_smile:

2 Likes
#45

Yeah. I realized that would be an issue. Count = frag x image pixels.
However I have done many more than this in the past :slight_smile: 

It is more of an arch issue I think. The compute prob should write particle ‘patches’ out to a number of textures with multiple dispatches (thats what I was referring to above). Then the patches are written directly rather than via the fullscreen shader.
Current version also could do with getting more ops in the compute shader too - ie each compute maybe handles the updates of a number of particles, and not just one :slight_smile:
Anyway
 will look at later. Thanks for the response.

1 Like