Dual Quaternion Blending

By default BonesPro uses linear blending to deform the mesh. Alternatively there is also the option to use dual quaternion blending. Dual quaternion blending deforms meshes differently and avoids the loss of volume during rotations. A subsequent drawback is that meshes can look too bloated in some cases when using dual quaternion blending. In order to optimize the final result it is possible to combine both blend modes and deform different areas of a mesh with either of them or an arbitrary mix of both.

Enabling Dual Quaternion Blending

The Dual Quaternion checkbox in the main rollout determines if quaternion blending is used at all. As long as this option is deactivated BonesPro deforms meshes exactly like older versions that had no dual quaternion support. Once this option is enabled each vertex will be deformed with a selectable blend between the traditional linear and the dual quaternion modes. By default all vertices are fully set to dual quaternion blending so that enabling the checkbox results in a fully dual quaternion blended result.

Adjustable Dual Quaternion Influence

BonesPro provides different options to adjust the dual-quaternion blend influence for parts of the mesh to allow selective mixing of both blend modes. While it is possible to use all these options to adjust the influence none of them will actually affect the mesh unless the main dual quaternion option is enabled. Users can adjust this blending through the following means:

Manual Values

The Vertices Rollout has an option to set the influence of dual quaternion blending to selected values on a per-vertex basis. Just select the vertices you want to change and enter the value of your choice. This is useful for quick changes to large mesh areas. A significant contrast between the blend modes can subsequently be smoothed with the paint tool’s smoothing option.

Vertex Painting

The BonesPro paint mode can not only adjust vertex weights it can also adjust the blending between linear and sual quaternion deformation. Just select the corresponding radio button and start adjusting the influence. All paint options including smoothing are available as they are during weight painting. Keep in mind that the quaternion blending is more sensitive than the normal weight painting and the paint strength should be lowered accordingly.

MAXScript

The dual quaternion influence is also fully accessible through MAXScript. This allows users to create procedural effects of their choice or create custom exporters with support for selective dual quaternion blending. Refer to the MAXScript chapter for details.

Visualizing Dual Quaternion Influence

The BonesPro visualization mode displays the influence of the two different blending modes whenever it is enabled but no bones are selected. If bones are selected it shows the deformation influence of those bones instead.

By default BonesPro uses a grayscale gradient from black (full linear blending) to a bright gray (full dual quaternion blending). The colors of this gradient can be changed in the options menu.