Hi,
I have this really bad flickering problem when i use a landscape. I am using tessellation but is the problem with tessellation or the Engine? I have looked at other posts and they said the world displacement needs to be above 0 but its already above 0 so i don’t seem to know what the issue is. The Engine i am running on is 4.14.
Thanks,
Iby
Edit: Forgot to upload a screenshot:
Hello Iby,
If you are using Displacement or World Position Offset in your landscape’s material, then the flickering you are seeing is more than likely a bounds scale issue. What that means is you are pushing the vertices of your landscape outside of it’s default bounds, which defines whether or not that particular landscape component is culled or rendered.
There is a visualizer within the viewport you can use to see the bounds of any object you have selected. Below I have outlined a quick example of visualizing your landscape’s bounds, and modifying the ZExtension in the positive or negative direction.
Bounds Visualizer
Here you can see the bounds of each landscape component.
Default Landscape ZExtension
As you can see when using Displacement my landscape also flickers and renders with missing components.
Modified Landscape ZExtension
Once I modified the ZExtension values, the flickering goes away. Be sure not to extend the bounds by too much as it can begin to cause performance issues.
Hopefully this helped and let me know if you have further questions or need additional assistance.
Cheers,
Hi,
I see. Thanks for the quick response i was getting dizzy trying to work on it whilst ignoring the flickering. Since it being expensive, whats the recommended guideline/optimal settings for using ZExtension amount in general? or is this usually done through trial and error?
Thanks,
Iby
Hi,
I Just increased the Zextension to 6.0 like the example you have given which worked great! However there seem to be some brief culling whenever i move the camera rapidly or when I move to the character’s Perspective. is this normal or should i raise the ZExtension further?
Generally I do this relative to the amount of displacement I am using. I would do this linearly by increasing in single integer increments. Keep increasing until you no longer see flickering.
Check your performance by monitoring your frames per second and using the profileGPU command to gauge the impact of modifying the ZExtension.
Thanks for the help. I was able to stop the flicker by putting the Zextension amount to 8.7.
