forge-skinning-animations

To animate skeletal meshes in an SDL GPU project, you apply glTF skinning data including joints, inverse bind matrices, and per-vertex weights to deform meshes via a joint hierarchy and animation channels.

glTF skinning works by computing per-frame joint matrices for the skeleton hierarchy, passing them to a vertex shader that blends up to four joint transforms per vertex using inverse bind matrices and per-vertex weights for mesh deformation.

You need a loader to parse glTF skins containing joints, inverse bind matrices, and per-vertex weights, then evaluate animation channels and propagate hierarchical transforms to compute per-frame joint matrices for the vertex shader.

Yes, you can use four-joint weighted skinning for glTF models in SDL GPU by evaluating animation channels to update joint matrices and applying a shader that blends up to four joint transforms per vertex for real-time character deformation.

glTF skinning animations fail to deform meshes correctly in SDL GPU when the loader does not properly parse inverse bind matrices or the vertex shader incorrectly blends the four joint transforms using per-vertex weights.

The best way to evaluate glTF animation channels for skeletal skinning is to compute per-frame joint matrices by propagating hierarchical transforms through the joint hierarchy before passing them to the vertex shader for mesh deformation.