Question about Geometry Collection, HLODs and HLODModifierClass

Development World Creation
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Hello! I need some help/advise with Geometry Collections and HLODs using World Partition.

My game has some destructive elements and I need to figure out how exactly make these elements bake into the HLODs or something similiar to maintain visual fidelity at distance.

I have a base level that consists of simple geometry, onto which I have placed the Geometry Collection of simple fence.

[Image Removed]After that I adjusted some setting inside Geometry Collection “Rendering Tab”.

[Image Removed]As you can see I have used Root Proxy Data settings (without this properly adjusted geometry Collection won’t bake into HLODs). And only after that I was able to actually BAKE some HLODs.

[Image Removed]This looks like some succes result but it’s not :frowning: Geometry Collection ‘resets’ after i move around the level. This looks weird enought to say that this is not the result I am searching for. You can watch attached “Demonstration.mp4” to understand what I mean.

QUESTION: As far as I can see, there is a setting inside HLODLayer that allows you to modify HLOD Modifier Class and select something like WorldPartitionHLODModifierMeshDestruction.

[Image Removed]But there is zero information in web about this settings and how to use it. I’ve tried some experiments but for me it looks like this setting doesn’t work at all. Description says it should allow changes to the HLODs at runtime. As I understand - this modifer should bake some HLODs with vertex color, which should work as masks to hide destroyed elements inside HLODs at distance.

Can someone explain what is HLOD Modifier Class - WorldpartitionHLODModifierMeshDestruction and how to make it work? Or maybe advise another way to make GC work with HLODs inside Wolrd Partition levels?

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Steps to Reproduce

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Hello!

This HLOD Modifier Class is not what you are looking for. It’s an advanced feature that allows destroyed/deleted actors to have their representation hidden in merged HLODs meshes and/or instanced HLODs. Think of the building parts in Fortnite. They rely on this system to have the HLOD updated to removed parts that are destroyed by the players.

What you are seeing is what I would expect. Actors that are in a World Partition cell that is streamed out will lose their state and will ultimately be garbage collected. Upon reloading that cell, those actors will be reset to their initial state. This won’t work unless you have some kind of persistence system that can restore your actor’s state.

HLOD are meant to be static. That kind of complex physic destruction can’t currently be represented by the HLOD system.

Regards,

Sebastien