Static mesh visibility flicker

Hello,

My static meshes flicker, going from invisible to visible (or so it seems) multiple times per second.
These are meshes I made in Maya (Polygon Cilinders with 4 sides, 500 units high, radius of 17.5 units), imported into Unreal Editor as FBX files. I made 2 uv’s, 1 for texturing and 1 for lighting. These are far from perfect, I only made it to demonstrate the problem with the simplest of objects.

  • This is the standard FP view project template (no blueprints) with some columns & BSP’s in front of it. Lightmap coordination index set to 1, lightmap resolution settings changed between 64,128 & 512.

When I view them from the back everythings fine. When I view them from the front, partially covered by the BSP’s, they start flickering like mad.
I’ve tried stretching my UV’s & rearranging them, but to no avail. Splitting my mesh up so that the texture squares match the BSP’s seems to help a bit but still doesn’t completely remove the problem.
Seems like a real beginners (which I am) error but I cannot seem to find the cause.

btw: flicker starts here: - YouTube

Hi Funt,

As the first post you linked to suggested you’ll want to adjust the bounds scale to help with the occlusion that is happening.

It’s best to turn on the bounds so you can see where the distance is that causing the issue.

In the viewport > Show > Advanced > enable Bounds.

Then select the four meshes and go into the details panel and adjust the bounds scale upward. I set up a scene like yours and using a setting of 10 more than took care of my issue (I used the same asset that was used for the pillar that was flickering in the tutorial video: SM_Pillar_Frame300)

After setting the bounds scale I was no longer having the issue. Also be aware that if the max of 10 does not work you can manually type in a value that is larger to fix the issue. But be aware that this could lead to performance and shadow quality.

Thank you!

Tim

Hi Tim, ty for your answer.

Would you happen to have some more insight as to why this is happening?

My “main” project basicly has alot of pillars and some 20’ish panels so far. It feels kinda weird to start altering settings which warn me about quality & performance loss when I’ve only just started putting some basic things together.

I’ve changed my pillar so that the texturing squares are somewhat more simular in size as the BSP boxes in front of the pillars, changed the origin of those pillars to half their height & set the bound scale to 2 so far. While this seems to have removed the flicker it doesn’t really give me more of an understanding as to why it happened in the first place.

I’m afraid I’ll end up doing alot of work only to find out I’ve been messing up the basics and having to start all over again.

So far I’ve tried various UV and mesh sizes, set up a Cull Distance Volume to always keep it shown, changed various lighting settings but none of them seems to help.

Would you happen to have some more
insight as to why this is happening?

The mesh is being occluded by the foreground objects. By increasing the bounds scale this will keep that mesh from being occluded. I Went back and re-did my test scene. only because I forgot to save it (Durr!) and was able to not have to set it that high. I used a scale of 2-4 depending on distance to get rid of the flickering.

My “main” project basicly has alot of
pillars and some 20’ish panels so far.
It feels kinda weird to start altering
settings which warn me about quality &
performance loss when I’ve only just
started putting some basic things
together.

The quality and performance loss is due to keeping the object visible when it may not need to be. The engine does a good job of occluding assets to keep performance up. By adjusting the scale you’re keeping the objects it wants to occlude in the scene longer that can lead to performance issue if you’ve got very complex meshes and a ton of things going on. If it’s a simplistic or moderately filled scene I’m not sure you’ll see a significant hit. You can always test this out by setting up a scene with more of these than you need and test the settings change to see if you see a real performance loss. The warnings are there to give you a heads up. It’s not saying that it’s a definite in every case. A lot of settings are default settings that we feel are the baseline. These are going to be adjusted based on a project basis dependent upon your needs.

I’ve changed my pillar so that the
texturing squares are somewhat more
simular in size as the BSP boxes in
front of the pillars, changed the
origin of those pillars to half their
height & set the bound scale to 2 so
far. While this seems to have removed
the flicker it doesn’t really give me
more of an understanding as to why it
happened in the first place.

I’m afraid I’ll end up doing alot of
work only to find out I’ve been
messing up the basics and having to
start all over again.

Adjusting the texture size will not affect the mesh “flicker.” This is your material setup only and how that will be handled with your mesh.

Setting the bounds scale will fix the issue so that it keeps the object rendered without being occluded by other objects. This is, again, where the performance issues can happen since you’re telling the engine to not occlude the object.

I see, thx for taking the time to explain.