Particle Emitter performance

Question

Created Oct ’15

Replies 7

Boosts 0

Views 1.4k

Participants 5

I use quite a lot of particles in my game, and I'm getting some performance issues under iOS 9.

Spritekit now has an extra draw call for each Particle Emitter. So if I had 20 particle emitters in the scene, the draw call is increased by 20. This happens if the particles from the different emitters have the exact same texture and z position. This is obviously bad, as these particles should be batch drawn together. It affects performance quite significantly.

iOS 8 worked as it should, not increasing the draw call for each particle emitter with the same texture and zpos.

I've lodged a bug report for it, but has anyone else noticed it?

Dan

Boost

Answer 1

Floating Wrench OP

Oct ’15

Just out of curiosity, have you tried setting the emitters to different z positions to see if that improves performance?

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Answer 2

hareball OP

Oct ’15

I just tried it, draw count is exactly the same if I use different z positions for the particle emitters (increases by 1 for each PE)

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Answer 3

TernTek OP

Oct ’15

We are seeing the same issue here with each particle requiring a separate draw call.

We still get resonable performance on iPad Air, but when we run on an older device such as iPad 2 frame rate drops 10-20 FPS.

To maintain reasonable performance on older devices, we only enable non-essential particle emitters for Metal devices.

We detect Metal devices with the following:

#define IS_METAL_DEVICE (MTLCreateSystemDefaultDevice())

if (IS_METAL) {
... add non essential particles
}

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Answer 4

greven OP

Oct ’15

Hi hareball,

Thanks for posting and reaching out. Do you have a radar number for your bug report?

Cheers

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Answer 5

hareball OP

Oct ’15

Hi greven,

Yes the bug # is

22871593

Thanks

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Answer 6

hareball OP

Oct ’15

Good tip, thanks I might use this until it is fixed.

Important to discern though, that it's 1 extra draw call for each particle emitter, not each particle (That's what I've noticed in my testing at least).

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Answer 7

ismyhc OP

May ’19

Im seeing the same issue still in latest versions. Ive tried searching for the radar bug you listed. Was there every any resolution to this?

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