[BUG/REGRESSION?] DrawMaterialToRenderTarget Hitches

I’ve observed an unintended behavior with DrawMaterialToRenderTarget blueprint node.
When you are using several of these in a blueprint, with different materials and targets, it causes progressively deteriorating hitches:

1 minute into the game:

3 minutes into the game:

5 minutes into the game:

10 minutes into the game:

And so on, up to tenth of a second and above.

Can’t say for sure, if the issue was there in earlier versions.

This could be related to the mesh particle bug where someone shows an identical deterioration. Perhaps their bug wasn’t with the actual particles, but with the core rendering thread?…eavy-fps-drops and here 4.19 & 4.20 Editor & Packaged Games Have Hangs/Hiccups Constantly - Feedback for Unreal Engine team - Unreal Engine Forums

A rising peak, over time, like that usually means that there is some type of a leak where there is some kind of x=x+1 type additive error on the input for loop count.

It certainly has exactly the same symptoms. But it is not related to mesh particles, or particles at all.

I didn’t say that it was related to them, i said it was related to a possible bug in the core rendering thread. Both are exhibiting similar symptoms, both share the rendering thread in common, therefore, the bug is probably in the rendering thread.

We have rendering thread performance problems with 4.19 on iOs. It’s starts fine but after a while there start to be spikes per 5 frames of something like that. Really hard to pinpoint what is causing it.

Yes, it is the same issue. It seems to be so. You are more than welcome to join us in the other thread.