pravusjif
commented
2 years ago Debugging findings
-
It was reported that several scenes were having invisible asset bundle meshes after updating the Asset Bunbdles Converter.
-
We reverted the latest AB Converter update, re-converted the affected scenes and invalidates the CDN ABs cache.
-
After debugging the issue for a week using one of the affected scenes, with which the problem can be reproduced converting locally, the following is a report on all the findings until now:
-
Some commit hunting shows that the scene is converted fine before the GLTFs Multi-Threadding update was merged in master (
569a6a796b24bca9e58650cd94fb49fe21772ec3) -
Debugging was done checking the diff changes introduced in that commit and also testing local conversion with the previous commit (
7d22053c23bf35fb3607632db57a918ee1181bc2), that converts the scene fine. -
Debugged converting the following scene: -8, 100 (university scene)
- Isolated asset conversion tested:
{ "file": "models/ParisNFT/BoothPremium/PNFT_BoothPremium.gltf", "hash": "QmR4NymhuRnJM9X1afKJoDgifkUm6Sg7hHch2GkTDKSnS3" }
- Isolated asset conversion tested:
-
When converting an affected asset in an isolated way I could reproduce the problem as well, and after solving that I discovered it was only a problem for isolated assets conversion and didn't fix the whole scene conversion. That means that when that asset is converted in an isolated way it converts fine, but when it is converted along with the whole scene, its conversion is broken and it ends up being invisible.
-
Further debugging showed that the affected assets are being created without a mesh and that's why they are invisible.
-
Another thing found when examining the visual tests comparison between the GLTF version and the Asset Bundle version of the converted assets is that when the editor imports the GLTF version, it's already invisible, so the actual problem is no in the conversion but in the loading of the original GLTF asset during the conversion process.
-
The problem is specifically happening on some GLTFs with external dependencies (buffer and texture files).
-
The NullReference exception we see when converting the affected assets is due to the GLTFSceneImporter not finding the previously-injected BUFFER FILES or TEXTURE FILES. Actually they are downloaded but the STREAM object is lost at some point (or not correctly loaded from the PersistentAssetCache)
-
If we remove the buffer assets cache list clearing that happens at
Core.DumpGltf(), the problem appears to be solved- In the pre-multithreadding commit we also cleared the buffer and image caches in
Core.DumpGLTF(), but with the multi-threadding commit we moved that toCore.CleanupCache() GLTFSceneImporter - Error - Buffer file not found (/Users/pravus/git/unity-renderer/unity-renderer/Assets/_Downloaded/QmRvnNSpUpyueXX7QUMxLGGNRh4dF3rjYh4eCJ7GWth1Lt/MainEntranceRightDoor.bin) -- MainEntranceRightDoor.bin- Triggers the usual NullReference exception when the buffer file is not found
- When converting this asset in isolation, the buffer file appears to be downloaded/injected after the GLTF, when it should happen before as with the dependency textures
- In the pre-multithreadding commit, this asset conversion is also broken, so we can skip debugging it.
- 3 assets not being converted
- Visual Test Detection: FAILED converting asset -> QmQvNTs1uNYiWty6v6iTEGz72tzLRjvgnFUytkYXZtpZXf
- Visual Test Detection: FAILED converting asset -> QmW4LiUDdut1ygU9wZErasLpyXg2gBbcYSV9KtcqnkiFVq
- Visual Test Detection: FAILED converting asset -> QmYtLrvWoAcUhXDTpmETMmLmtBSFGJz53urEzPqcYqtDB9
- In the pre-multithreadding commit, only 'QmW4LiUDdut1ygU9wZErasLpyXg2gBbcYSV9KtcqnkiFVq' and additionally 'Qmf6YeiSSNrbhvr3WiFwmB26aC13ccebm9SgaGPgYXnDhM' assets fail converting.
- In the pre-multithreadding commit we also cleared the buffer and image caches in
Next
- Will remove clearing the buffer cache on every GLTF dump (since with multi-threadding commit we moved that to Core.CleanupCache()`) since that fixes the problem and will test the fix with the other affected scenes.
- Will try to add some test coverage, maybe a visual test with a local gltf in test resources
- Will make a list of all the cases of textures being shared as linear and non-linear, to communicate that to the creator
We have reports that these scenes are having invisible assets after re-converting with the latest Asset Bundles converter update:
the AB Converter updates has already been reverted.
We should:
NOTE the first 4 scenes have already been re-converted during the weekend and the cache already invalidated so they are looking fine in production.
Edit:
Updated Tasks: