HLOD Elements Shadows are flickering

We are using 4.11 and have been implementing HLOD Clusters in our levels. We noticed after creating some HLOD that the shadows in the scene now flicker. Not just on the HLOD cluster actors themselves but also on other mesh in the scene too.

The actors in a HLOD cluster shadows flicker on and off at different angles when the mesh itself is not being rendered. It also seems to be causing the same effect on other unrelated static mesh in the scene too.

Here is a video showing the Shadow Flickering. This happens in PIE, and in Cooked builds.

Youtube video of HLOD Shadow Flickering

I should have also mentioned that deleting the HLOD Clusters from the level removes the shadow flickering seen here.

It’s apparently a feature that’s been in development since November 2015:

I’d love to know the status of UE-22627 … Otherwise HLODs are kind of useless to my team right now.

In my project hlods are a huge boost but useless with shadows flickering.
Where I can follow the status of UE-22627 ?

That ticket was marked as fixed for 4.13, although it shouldn’t be a problem with 4.12, at least from what I’ve seen when using them in scenes. 4.11 may have had more issues since the feature was still actively being developed at the time and 4.11’s code was branched in February or earlier IIRC.

@UppercutAJ

I’m fairly certain this issue has been resolved with 4.12 and later. I’ve not setup a test comparison but seems like it should be fixed since I’ve not seen the issue in 4.12 at all while using them although there could be a specific instance that causes it to happen that I’ve just not run across. If that is the case, feel free to post some steps or notes here and I can investigate further.

Hey ,

This is probably a long shot, but is there any chance you could find out if there’s a commit (or a handful of commits) associated with the ticket? I’d rather cherry-pick a few changes than upgrade to 4.12 at this time.

CL-3038085 was marked as the fix. 4 files total. There may be others, but this is the ones associated with this ticket.

We have the same issue and I just tried to merge the mentioned commit.

Apart from this changelist being for the internal perforce and not the public git, this change alone isn’t sufficient. It’s far to reliant on changes before, so I don’t think it’s easily possible to merge this fix into 4.11, unfortunately. It was worth a try though.

Thank you for posting your results and saving me time.