Compressed Texture Support (webp, KTX) in Unity

Cesium for Unity
1

I’ve processed the glTF models of my tileset with gltf-optimizer to apply Draco mesh compression and webp texture compression.

When I load this tileset on a Cesium JS client, everything loads as expected. However, when I load it in the Cesium Unity Samples project, no textures are applied to the models. I did not use version 0.3.0 of the Samples project due to a NullRef exception when loading this tileset from disk.

My understanding is that Cesium Native should handle loading compressed textures. What options do I have to investigate why Cesium Native is not loading these textures?

2

Yes you’re right, we should be handling both KTX2 and WebP compressed textures, so I’m not sure why that wouldn’t be working. Can you point us to a sample tileset that we can use to investigate the problem?

3

Here’s the tileset download: https://api.cesium.com/v1/assets/1571491/archives/7789/download

4

I’m getting the same result using another webp compression tool, gltf-transform.

I’ll update this once I test with KTX2, though this tool doesn’t seem to be able to compress the textures on my models with that yet.

5

Same issue with KTX2 using etc1s compression, I didn’t apply Draco compression this time, here’s the tileset: https://api.cesium.com/v1/assets/1571608/archives/7798/download

Cesium JS is able to load the models as expected but Cesium Unity Samples loads gray models without textures:

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6

Thanks @dagrooms. Would you mind sending me a private message with a access token I can use to access this tileset and your permission to access it for debugging purposes?

7

Here’s a GitHub repo so we don’t have to mess with access privileges: GitHub - dagrooms52/3DTilesCompressed

8

Were you able to run the sample data I shared?

9

Yes, thank you for that! I just opened two PRs with fixes for the texture problems you saw:

This will be available in the next release, currently planned for early April. Or you can grab a build out of our CI system if you want to try it sooner.

2 Likes
10

I created a pull request. I think my PR is also related with this thread.

When the PR is reflected, if gltf using compressed textures (e.x KTX 2) then GPU memory (VRAM) usage is reduced.