Locking up during path trace render using render queue

I’ve been using the path tracer a bunch since the updates in 4.27. It’s a fantastic addition to my workflow, but it keeps locking up after the preview window pops up. It sits at like 6% CPU usage and 0% GPU usage and never resolves, even after 20+ minutes. When it works it finishes in about 3 seconds, but it frequently just…won’t. I have to kill and restart and try again. Any ideas what could be causing this?

I’m running a Ryzen 5950x and 3070ti, 64gb of ram, just a jpg output with only the path tracer on, 256 samples per pixel, 2048x2048 image, no additional AA.

Hi Lech00ga !

You need to make sure the window where the Path Tracer is rendering is in focus, or the ray convergence will pause (and feel like its locking up).

Your setup shouldnt have any troubles rendering with the Path Tracer ! :slight_smile:

Are you using the Movie Render Queue and Stills tools ?

Cheers,
Antoine

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Been using it for a couple more days now and haven’t hit any issues since I’ve kept focus while outputting and got the settings dialed in a bit. Definitely user error D:

Yup, using the Movie Render Queue. I’m not sure I’m familiar with the Stills tools? I’ve been making a level sequence that’s 1 frame long and outputting from there. Is there a simpler way to output a single frame (with cryptomatte IDs) from a designated camera?

And thanks for the help!

The tool has not really been promoted yet on the documentation, but does the technique you mentioned (one frame sequences) automatically for a selection or all scene cameras. It also allows to override preset settings like resolution of the frame, tiling or samples.

You will find the tool in the MovieRenderPipeline Content plugin folder, as the Editor Blueprint Utility “StillRenderSetupAutomation” in the Editor/Stills.

This is a first iteration of the tool, but we hope it will help make still renders much easily and quickly !

Cheers,
Antoine

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Well, perfect timing, we just published the doc page for the stills tool :slight_smile:

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This is awesome! Thanks for letting me know about this, it’s definitely saving me a few steps. Excited to see where it goes.

Just to throw my two cents in, I would love a feature to lock output aspect ratio to camera aspect ratio. We’re outputting for print, so sizes can vary quite a bit. I recognize this is an edge use case so I won’t be disappointed if it doesn’t make it in there. Love the direction everything’s going, thanks again!

We actually already discussed the locked ratio internally, its on the list of features for a future release. :slight_smile:

Cheers, enjoy the tools !
Antoine

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Wanted to revisit this with a little more rendering under my belt. So it does seem to lock up for me if “overwrite existing output” is NOT checked when I render with the path tracer.