What's causing fuzzy edges when in motion?

What is causing this ugly edge effect when in motion? I’ve tried all the AA settings and disabled motion blur, didn’t help.

10864-ue4_funnyedges.jpg

Do you have a Scene Capture 2D actor in your level?

Nope. Also it happens with a clean default level too.

I was told by a UE developer that the answer might lie somewhere in the Post Process node. The node is so huge though, that I decided to put that quest off for another day… :stuck_out_tongue:

You said you disabled motion blur; did you make sure to disable it in every relevant post process volume AND in whatever camera you’re using?

If so, does this happen when launching in a standalone game instead of viewport mode?

There’s only one post process volume and the camera has it disabled too. And starting in standalone game shows the same thing.

However, I just noticed that it doesn’t seem to be the case when I start in VR mode! I probably never noticed because the Rift resolution is so low, but starting in VR mode without the Rift shows that everything stays sharp including shadows from the moving object.

So now it’s a case of finding what changes for the better in VR mode.

Hmm any more ideas anyone?

That a down-sampled buffer being mixed into your final render for some type of post-processing effect. Probably quarter resolution by the look of your screenshot.

Use ‘r.CompositionGraphDebug’ while it’s running and you can see the list of input and output buffers for the whole render. Most things have a meaningful name (like “VelocityBlurX”) so you should be able to figure out what type of post-processing is still happening. Experiment with turning things on and off, and you should be able to find the culprit.

My guess would be that motion blur is still on somehow, but I couldn’t know for sure without seeing the debug information.

It’s a blueprint-only project for now. Any way I can get this info without code?

I guess I didn’t mention that that’s actually a console command. While you’re running the project you can press tilde key to bring up the console and type in commands. It’s useful for changing settings and getting information at runtime. In the graphics programming documentation (Graphics Programming for Unreal Engine | Unreal Engine 5.2 Documentation) there is a whole list of commands that you might find useful. There are lots of others though that you can look into if you’re interested.

Did you try creating a post processing volume and setting TemporalAA to FXAA?

Oh right, should have figured that out on my own. Sorry about that.

There’s lots of stuff in the resulting gml file, I’ll try if I can find something.

Yes indeed I use FXAA because temporal looks wrong in VR. Tried disabling it too, still the same issue.

Interstingly enough, like I mentioned earlier, when playing in the Rift the fuzzy edges are gone.

So I’ve got a nice diagram now but don’t know what to do with it. You know, I’ve disabled the whole postprocessing volume but the issue persists. Should I assume then that the problem lies elsewhere?

Anything on that list is still being rendered so those are the things you need to investigate. Go through the list and alter the settings for everything you see until the problem disappears (or gets worse). You should, for example, see where your antialiasing is applied so try altering those settings or disabling it to see if it changes anything. Keep following the chain of buffers back until you get to the start of the render. Somewhere in there is your problem. If you’ve disabled most of your post-processing it should be a pretty short chain.

So I’ve disabled the whole post process volume and executed the command again. The result is a diagram with one root node and nothing else. But the issue is still there.

Maybe it’s a rendering bug after all?

Actually, scratch that. I just forgot to do a hierarchical view of the new diagram. I’ve also not disabled post process per se, just the volume…

Go to “Render settings > Motion Blur” and uncheck it.