Particle Systems render wrong texture while using Graphics Jobs in 5.5

Since we upgraded to 5.5, our particle systems sometimes render the wrong textures when using Graphics Jobs, like that:

It seems to be somewhat random and it just flickers on and off. The replaced textures are often hard to recognize, but some of them seem to be Speed Tree billboards. It also seem to depend on the viewport position of the particles, as it happens more often when the particles are close to the edge of the screen. My guess is that it comes from some kind of race condition in particles rendering when using graphics jobs, but I can't know for sure.

For now, we've been unable to reproduce the bug in a separate project that we could use for a bug report, and we're unable to pinpoint exactly the conditions needed to get this bug.

Did anybody see this and know a workaround to fix it?

 

We have concluded that the problem resides in the SpeedTree new billboard shader; replacing the 5.5 shader with the 5.4 one fixes the aformentioned issue.

@maxxa05 could you please update the post title to better describe what's going on here? Better are the chances that the right person from the graphics team at Unity will take a look at this if the title reflects the actual problem (which might well be SpeedTree shader in this case).

 

Hi Karl,

We are running the project on PC and PS4 on p2 and on p1 on Xbox One. The only platform that we couldn't reproduce it is PS4.

We are doing our best to shrink our project to fit the 2 gb requirement, but anything we do to reduce its size get rid of the issue for some reason.

For now even the shader replacement fix did end up not working. It's pretty random actually and very difficult to find solid repros.

Disabling Graphics Jobs is the only workaround, and that's a shame to not have that on Xbox.

 

Hi Karl, issue #863719 has been submitted and we're zipping our project in order to transfer it to you once we receive the details. Cheers!

 

We just tested, it's still happening in 5.5.0p3