Donovan Hutchence

Hey @LeXXik, @leonidaspir, Can you explain where you're using glTF export atm? Thanks!

Oh that's interesting. I never realised our lighting basis is wrong on the back faces. (We were aware of WebGPU issues though). Thanks for pointing this out!

I would have expected backfaces to be handled by this bit of code here: https://github.com/playcanvas/engine/blob/main/src/scene/shader-lib/programs/lit-shader.js#L989 The actual tangents and binormals are calculated in this shader chunk: https://github.com/playcanvas/engine/blob/main/src/scene/shader-lib/chunks/lit/frag/TBNderivative.js

Hi @erikdubbelboer, Looking at the changes, I think it makes sense to handle twoSidedLighting in just one place - after dTBN has been calculated. This is probably best done in...

Noice! @mvaligursky has actually done a lot of research in this area and ended up creating a ticket on chrome bugs because it doesn't parallelize correctly and it's very difficult...

Our gamma space textures also currently have their mipmaps generated in gamma space, which is wrong. Marking texture sRGB will result in linear-space generated mipmaps. We also need to address...

I believe #6357 might have addressed the underlying issue (which was updating the sort buffer in a `setTimeout` callback). If you experience this issue again using up-to-date engine please post...

You're right @pjbaron that this function is being slightly more careful than strictly necessary, but the performance difference you're proposing is minute and only effects loading time or conversion time...

On iOS the model must be converted to usdz. My guess is our converter isn't taking some of the node scaling or skinning into account.

The usdz code is in the engine, so actually yes please make an issue there. cc @mvaligursky