Cesium OSM Buildings Lumen Issues

Cesium for Unreal
1

Hello,

So I have OSM Buildings in my Cesium Project which I am using as a base to generate procedural windows on. I don’t render the OSM Buildings at all and instead overlay that material on the regular Google Earth tiles. I’m using the Cartographic Polygon Component workflow to remove certain buildings as well because I already have modelled versions of them. However, I’m noticing that Lumen is still using those buildings to do its thing and it’s causing artifacts. I assume this is because the Cartographic Polygon is just masking and not removing the meshes from the scene. Can anyone think of a potential fix? I can’t use “Actor Hidden in Game” because I need the material that’s on these buildings.

Essentially I need to do this (from UE’s documentation):

In cases where you have problem-causing meshes contributing to indirect lighting, they can be removed from Lumen Scene using by using the Level instance’s Details panel to disable one of the following:

For “Software Ray Tracing”, unchecking the box for Affect Distance Field Lighting removes them.

For “Hardware Ray Tracing”, unchecking the box for Visible in Ray Tracing removes them.

However, I can’t find these settings on Cesium’s OSM Buildings…

Thanks,

Aidan

OSM_Buildings
OSM_Buildings1308×812 236 KB

No_OSM_Buildings
No_OSM_Buildings1319×839 258 KB

2

I’m afraid I don’t know. You’re right that cartographic polygons work by setting the opacity mask, not by actually removing geometry.

As far as the lines you quoted from the documentation, one thing that jumps out at me is that it’s talking about level instances. A Cesium3DTileset is not a level instance itself, but you could certainly put it inside one if it helps.

3

OK, thanks Kevin!