Skinned mesh & morpher don't mix well on iOS

[rdpeake]

@sebavan the bone under morph seems to drift away from it’s skeletal positioning:

CPU skinning:

GPU skinning:

[sebavan]

let s see if @Deltakosh remembers how he fixed it ?

[Deltakosh]

Nope:( but we did several change recently around that function so this needs to be investigated

[sebavan]

@Evgeni_Popov could you have a look into this one ?

I tried all version since 3.3 and they are all consistently oulining differences between gpu and cpu process that I can t find at the moment.

[Evgeni_Popov]

I guess the problem is this one:

@sebavan

If it is the case it boils down to the fact that on one side we do bones then morph (when running on GPU) and reversly when running on CPU.

?

The PR (Fix #6526 · BabylonJS/Babylon.js@3b7c0f8 · GitHub) did not fix that, it fixed being able to use the GPU to compute bones when needInitialSkinMatrix=true.

I will have a look at it.

[Evgeni_Popov]

Computing bones on the CPU and using morph targets are incompatible, I have updated the doc about that:

Add warning regarding usage of computeBonesUsingShaders and morph targets

Note it is not a regression, it has never worked (it is “by design”).