3x1t-5tyl3 commented 3 years ago

Describe the bug

When exporting from Blender to GLTF 2.0 and importing to Neos, "Shape Key Tangents" are not properly imported which causes flipped tangents on models when using blendshapes.

Relevant issues

782

To Reproduce

Download the Model provided
Export the model with the settings (screenshot 1) provided.
Observe flipped blendshapes on use everytime.

To Reproduce entirely from scratch

Create any object in blender (vertex count or anything else doesn't matter) in this example a simple Cube is good enough.
Add the base shapekey and a seperate shapekey and move any vertex to make a valid shapekey.
Follow "To Reproduce" steps 2 and 3.

Expected behavior

NOT enabling this rejects tangents for shapekeys but is a workaround for now. Though given this is in the GLTF standard it would be pretty good to still have the proper ability to import this properly.

Screenshots / Video

grafik https://user-images.githubusercontent.com/61988002/116230126-90e74100-a757-11eb-99cf-073698f9a201.mp4

Bug information (please complete the following information):

How often does it happen: Always
Does the bug persist after restarting Neos? Yes
Neos Version: 2021.4.24.849
Neos Platform: Only tested on Windows
Link to reproduction World/Item: GH2104-Cube-TestShapeKeyTangent.zip
Regression: Did this work before? Not sure. First time testing with no decent way to go further back.

Additional context

Importing the file with the tangents option enabled (which causes the bug in neos) into blender does NOT give any errors. As such it's expected that Assimp is at fault here.

Reporters:

3x1t_5tyl3# 0001

Frooxius commented 3 years ago

This is likely decoding error in Assimp, we'll have to update to the latest version from source and then check if the problem still persists.

ohzee00 commented 2 years ago

Sadly I can't test this issue currently but being Assimp recently got updated, is this issue fixed and can be closed?

3x1t-5tyl3 commented 2 years ago