I get random bright frames when rendering a sequence through the render queue. (Using UE 5.5).
I switched to virtual textures the other day, and now I’m getting these strange bright frames in my sequence. I also use virtual shadows in these renders, but they’re not the problem. Turning them off produces the same result.
The darker frame is the correct one (below). I get a few random frames like the bright one throughout the sequence and I can’t figure out why, it’s not the same frame every time. I can’t say for sure it’s because of the VT’s but it wasn’t happening before that. Are there textures that should absolutely NOT be virtual maybe?
No odd light settings, no odd camera settings, no moving lights, so I’m at a loss here. I tried rendering with no console commands, no game overrides or anything, but it still happens.
It’s possible if your lower-resolution maps are brighter. It’s hard to tell, but is the render of something reflective? Could something be culled, revealing something brighter in the reflection? Have you tried to disable all the overrides in “Game Overrides”
There are puddles but it seems like all diffuse maps are affected, it almost looks like a light passing by (that isn’t there). I tried that now, unfortunately it didn’t make any difference. I could probably go back to non-virtual maps, but don’t want to, they help so much with optimizing. It worked just fine before I converted the textures. Makes me think I might’ve maybe converted a texture somewhere that shouldn’t be converted, but I don’t know if certain textures (or uses of them) aren’t featured yet.
See this attached recording of the frames that glitch out. This is the raw render. (Also nice of you to reply buddy!).
I didn’t even realize who I was responding to. You can see if you are oversubscribed with your VTs, but normally, the issues I see are with low resolution not flashing bright. That is odd. If you disable Lumen does it still flash? I wonder if there is a mip that is super bright or something? If the project is not huge you can zip it up and send it to me and I can take a look.
It seems the fix is to turn off WPO leaf animations, but that’s not wanted. I found a supposed workaround where you change the ObjectPivotPoint node inside the SimpleWind (in a Megascans foliage material), to have its TransformPosition set to “Instance & Particle Space to Absolute World Space” but it made no difference. No wiser yet, apart from turning wind off.
I have not heard of that. If you have a small repro I’d love to get my hands on it to see if you stumbled upon an engine bug.
To me it looks like something bright is flashing lumen which is why it takes x amount of frames to come back to normal. Normally I have seen this from bad texture with negative or NaaN pixel values freaking out lumen. And I’ve seen geo with really wonky normals do the same. Maybe the WPO is freaking out the normals on the foliage? Maybe try and reprocess those normals if you can? I dunno man.
