pub const MORPH_BASE: u32 = 12;Expand description
Per-instance morph-weight base (Uint32), read from the instance
stream.
The instance’s first morph weight in the frame’s shared weight array;
the shader reads a target’s weight at this base plus its own target
index. It is a location of its own rather than a lane of
JOINTS_BASE because skinning and morphing are independent — a
variant that reads one has no business declaring the other.