Hi, I’m trying to create a Laser Security System and ran into an issue with the rendering of beam emitters in motion. Whenever two emitters that are moving in perpendicular directions vie for the same pixels, the intersection point and its immediate vicinity are rendered more brightly when compared to the rest of the beam. And this happens only when I’m using TXAA. Switching to FXAA mostly solves the issue, but then that causes the beams to flicker more and more as you move away from them. I’ve uploaded a recorded video of the issue for reference here: Dropbox - File Deleted
I just wanted to know if there’s a way to get around this problem without turning off TXAA.
What’s the render mode for the material set to? If it’s addative, then that is the result you can expect because it’s adding the two materials together at the intersection point. Setting the material to be translucent or masked would likely solve this issue.
Thanks for replying, @TorQueMoD. I’m using a translucent material for this one. I don’t have much experience with material scripting, but this is the laser material used by emitter:
However, when the character starts moving again (TXAA mode), the bright intersection spots appear again. Moreover, there seems to be some form of trailing effect near the overlapping points, trying to catch up with the view from the camera’s changing position. I don’t know if it’s related, but I’ve seen similar ghosting issues when using 3D widget components with motion blur and TXAA enabled, which again was solved by switching to FXAA.
Maybe it’s Motion blur that’s causing the issue. Try adding a post process volume to the scene and disabling the motion blur and then setting the post process volume to be Unbound so it applies to the whole level.
Tried removing the motion blur, the issue still persists. Also tested it out in an open level just to make sure that the artifacts are not just something that’s visible in very dark lighting conditions. It’s quite visible in brightly lit environments as well.
Alright, so just to make sure that it’s not some modified parameter within the emitter or material that’s causing this issue, I imported the electric arc particle system from the content examples pack. After changing only the source/target setup, and reducing the color emissivity, the imported emitter is also displaying the same properties (ignore the floor/wall contact points; that might be due to depth fade):
Well, tried it out in blank projects on a couple of PCs and it’s still the same.
So I’m guessing that this may either be a limitation with TXAA, or some issue with my systems. It would be great if someone could confirm this, or maybe point me towards some workaround to the problem.
