Generate Skin Weights For Head Retargeting¶
Input Streams: Mesh Stream and Animation Stream (REQUIRED)
Output Streams: Modified Mesh Stream (with skinning data)
The Generate Skin Weights For Head Retargeting Stage is used to automatically generate skin weighting to use for gaze retargeting, so that a volumetric player can be configured to have the actor dynamically turn their head to look at an object in the scene.
This Stage applies weight to the mesh starting at a certain point on the neck bone, and gradually increases until it reaches an end point on the neck bone. Below the start, all vertices have 0% weight, and above the end, all vertices have 100% weight.
“Skin weighting” is a concept in 3d graphics. It determines how strongly animation to the bones is applied to each vertex on a mesh.
This Stage should be performed on the final mesh and animation streams, and should not be placed above any clean, stabilize, or SSDR Stages on the Track.
% Up Neck 0 Weight: This is the percentage along up the neck bone, (measured from 0% at the base of the neck to 100% at the head bone,) where any vertices above will have some weighting assigned to the head.
% Up Neck Full Weight: This is the distance along the neck bone, (measured from 0% at the base of the neck to 100% at the head bone,) above which any vertex is 100% weighted to the head. This value should typically be higher than or the same as the % Up Neck 0 Weight setting.
Working with Generate Skin Weights For Head Retargeting¶
Between the % Up Neck 0 Weight and % Up Neck Full Weight, settings, there is a smooth transition in weighting. This smooth transition helps produce a natural deformation when the volumetric actor bends their neck when the head bone is animated. Any vertices below this point will be weighted to the body. Typically, you want the entire head to be 100% weight, so you should place the % up neck full weight setting below the actor’s chin. Oftentimes, the Up Neck 0 Weight setting can be 0.0, indicating the base of the beck bone, but this may need to be higher depending on the clothing or anatomy of your subject.