Module skeleton 

Skeleton maths for GraphicsMesh bones.

Convention (verified against all eight skinned meshes, combining weighted geometry with rigid node geometry when comparing stored bounds):

• stored quaternions are conjugated relative to the column-vector convention used here;
• world = parent_world * local;
• skinning matrix = world * inverse_bind, where inv_rotation/inv_translation is the inverse bind.

Skinned vertices are stored in a per-mesh frame; the bind-pose palette maps them to model space.

Structs

Transform

A bone transform: a rotation and a translation.

Functions

bind_palette

Palette for the bind pose.

inverse_bind

The inverse of a bone’s bind transform, for skinning.

local_bind

Bone-local bind transform.

palette

Skinning palette (world * inverse bind) for the given local pose.

skin_to_static

Skin 32-byte ModelSkinLayout vertices (i16x4 position /512, i16x4 texcoords, unorm8x4 normal, 4 unused bytes, unorm8x4 weights, u8x4 bone indices) with a palette into the 24-byte static ModelLayout (position, texcoords, normal, zeroed user data). Used to draw characters in a fixed pose without GPU skinning.

world_transforms

World transforms for the given local transforms (bones are stored parents-first).