Currently, my project has an “underground mode” that was created by toggling _Cull from Back to Off on every streamed tile’s material (Cesium3DTileset.OnTileGameObjectCreated was used to make sure that freshly generated tiles are also included), In theory, the terrain should look like a flat “ceiling” that would show the cities and terrain and not leave gaps (as shown below).
Are there any intentions for underground support in the future? As far as I have been able to see, there aren’t any. Is there any workaround or supported way to get a proper flat underside without switching to a separate bare-Earth terrain source entirely?
Hi @jswrk - just to confirm, you’re trying to support an underground view where terrain/city tiles look like a continuous ceiling from below, without switching to a separate terrain source.
Based on current Cesium for Unity APIs, there isn’t a built-in “underground mode” toggle that creates a guaranteed flat underside automatically. The supported knobs I can verify are tile material customization via OnTileGameObjectCreated, plus tileset refinement/culling controls like forbidHoles and frustum-culling settings on Cesium3DTileset (Cesium3DTileset.cs).
For the material side, your Cull Off direction is reasonable — Unity’s ShaderLab defines Cull Off as disabling face-direction culling (double-sided rendering) (Unity ShaderLab Cull docs).
Could you share your Cesium for Unity + Unity versions and render pipeline? I checked against the current Cesium for Unity changelog (latest listed release v1.24.0) (CHANGES.md), but I want to match your exact setup before suggesting concrete tuning values.
If helpful, I can suggest a practical configuration pass next (material setup + tileset culling/refinement settings) for a more stable underground experience.
That is correct, the goal is to have a continuous ceiling from below without using a separate terrain source (although, if that isn’t possible, that would be our last resort). My current versions are as follow:
Unity: 6000.0.76f1
Cesium for Unity: 1.23.2
Render Pipeline: URP (17.0.4)
If anything else is needed, feel free to let me know.
Furthermore, if the current underground geometry that is currently protruding (in the previous screenshots) is unable to be fixed, please let me know. It is currently located at roughly 34.04472695, -118.24928301.
Thank you again for taking the time to reply to my post. I’m still working on this specific issue and have tried various fixes, but we still see the underground projections/artifacts. I would appreciate any further suggestions or possible solutions as they would be beneficial to the completion of my project.
