Fix logical errors in byteStride calculations

[Yeah-Zi]

Fixed loading failure issue when byteStride description is 0 in buffer view

[kring]

@Yeah-Zi can you explain more why this is needed? If a bufferView has byteStride explicitly specified to be zero, that's a broken glTF. The value is required to be greater than or equal to 4:
https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#_bufferview_bytestride

[Yeah-Zi]

Thank you for providing the standard format specification for gltf.
Why I need this is because the customer provides data with a byteStride of 0, it can be loaded normally in CesiumJS, while Cesium For Unreal cannot

[Yeah-Zi]

@kring Perhaps some log information can be added here, as loading failure does not result in any errors. It took me some time to debug this error

[Yeah-Zi]

i found how cesiumjs due with this situation:
https://github.com/CesiumGS/cesium/blob/main/packages/engine/Source/Scene/GltfPipeline/getAccessorByteStride.js

[kring]

Perhaps some log information can be added here, as loading failure does not result in any errors.

I'm not opposed to adding some more logging but, in general, cesium-native is a loader, not a validator. A proper glTF validator (like this one: https://github.khronos.org/glTF-Validator/) should easily detect invalid glTF files like this.

However, in this case, since your change matches what CesiumJS is already doing, and it has very little cost, I'm happy to merge it. Can you please sign the Contributor License Agreement first:
https://github.com/CesiumGS/cesium/blob/master/CONTRIBUTING.md#contributor-license-agreement-cla

Thank you for the PR!

[Yeah-Zi]

@kring I have signed the CLA

[kring]

Thanks @Yeah-Zi!