Awful Trailing/Ghosting When Camera Moves Past Thin Meshes

Development Architectural and Design Visualization
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1

I have a scene of a store with metal cages built with glass with a thin steel frame.

When I move round in the editor the steel frames leave a trail over the walls. I first noticed this with a Cine Camera. But its the same just moving around in the editor.

How can i stop this trailing?

Please help!

A
A1920Ă—1277 230 KB

The metal frame (thin mesh framing glass - GREEN) is leaving trails on the walls when the camera passes

B
B1920Ă—1130 180 KB

C
C1920Ă—1498 260 KB

Here is the design for context. you can see the trailling behind the cage on the wall and refrigerator.

2

Hello there @Jac_Freeman!

From the looks of your screenshots, and without knowing the full extent of your setup and materials, there are a few general methods from the UE community, to try for the ghosting effect you are seeing. Let’s cover them one by one:

  • First of all, the most usual cultrip, your current AA method. Check your Project Settings > Rendering, and confirm your AA method, which is most likely FXAA. Test with TSR, TAA, and None. One of these settings could remove the trails altogether

  • Next, open your master material, go to Details >Transparency, check if Output Velocity and Responsive AA are enabled. If not, enable them (if they are greyed out, you may need to temporary change your material’s blend mode to Masked). This should help thin meshes to retain their shape during camera movement, avoiding the trails

  • Another possible cause, is motion blur. Open your post-processing volume, and check the values for motion blur in your scene. Test by reducing or, disabling them fully

  • FInally, if all fails, you can try slightly increasing the thickness of the affected meshes. A small bevel could be enough to prevent the ghosting effect

For further testing, there’s another thread with a ghosting scenario, please give it a look:

3

Thank you for the response. I have tried absolutely everything suggested online and nothing makes a difference.

Except, you inspired me with the translucency of materials. There is no ghosting of the thin meshes if the material is set to translucent. So I have created a translucent material and am trying to make it look as best i can.

There is still ghosting in the scene however. But none of it is as bad as the thin meshes were.

Turning off GI - Lumen does not help

Turning off AA doesnt help.

Turning of motion blur doesnt help.

Only slowing down the camera helps a little. So I am concluding that it is an issue with UE5? (Im using 5.4.4)

One thing I did think of… Could the issue be because I am using a Mac? I use an M3 Max with 40 core GPU and 48G unified Ram. (The memory pressure is always low however, as is the cpu usage).

Could it still be the Mac?

Anyway thank you for the suggestions, I tried the chamfer but it didnt help

1 Like
4

You are welcome! Glad you are getting closer to a solution!

Checking around the community, there aren’t cases with ghosting being tied specifically with Mac, so I don’t think that’s the case. What’s true, is that Mac handles graphics a bit different thant the usual DX12 buffer, so there are a few things we could test to further improve the solution here:

  • First, UE works with virtual shadow maps by default, which can have unexpected interactions with the thin surfaces you are working with. Test by going to Project Settings > Rendering and switch your Shadow Map Method from VSM to SM

  • Next, check your post-processing volume for any active Reflection method (most likely set to Lumen), and change it to None

  • Finally, even if you turned off GI, there might be a few features still active in the background. To ensure the engine is not trying to create reflections in the wrong places, open the console and input r.Lumen.Reflections.ScreenTraces 0