GLTFExporter: Fix normal computation with interleaved data.

[Mugen87]

Related issue: -

Description

GLTFExporter exports normalized normal data. To ensure this, there are two functions that check normal attribute data and update them if necessary. However, this logic did not work for interleaved normal data so far.

[mrdoob]

Thanks!

[ramirofages]

One question, I'm getting the (probably) same error regarding the normal computation with interleaved attributes when loading a glb file. The error happens when you call applyMatrix4 on a BufferGeometry that contains interleaved attributes.

I noticed that this issue was fixed for the gltf exporter...is the gltfloader working correctly for this?

(btw applying a matrix4 directly on the interleaved attribute works correctly)

[donmccurdy]

As far as I know GLTFLoader handles interleaved data correctly — it certainly renders correctly in many of my tests. Notably GLTFLoader does not process the interleaved binary data, it just passes it into a three.js InterleavedBuffer object. If you're getting an error when doing further work on an interleaved BufferGeometry, I think you may need to file an issue with example code.

[ramirofages]

Okay thanks for the quick response, I will see if I can reproduce this outside of my project tomorrow