Skinning Converter is a Houdini Digital Asset (HDA) that can convert any non-changing topology deforming mesh sequence into a bone based animation. The user gets control over a couple of parameters, which allows the user to get their desired result.


Direct Conversion

If you have a deforming mesh sequence, and would like to convert it to a bone-based animation, simply plug it into the first input of the tool. The interface provides a couple of parameters to tweak in order to achieve the desired result.

Global Settings

The "Convert to Bones" button will convert the input mesh sequence.

The user is able to change the frame range to bake, which by default is set to frame-range start-end.

The capturing method can be configured to either use Biharmonic Capturing, or Proximity Capture. It is recommended to use Biharmonic Capturing over Proximity Capture, due to the higher level of quality capture. You could however use Proximity Capture, to improve the speed of the capturing process.

The capture frame determines what frame will be used to determine the capture pose. It is recommended to use your first frame.

Max Bone Influences controls by how many bones a point can be influenced. Higher values could mean smoother results, but also increases overhead in engine.

Bone Placement Control

The Bone Placement Control tab allows you to choose between two methods of generating bone placements. Uniform and Adaptive.

Uniform will simply distribute the bones uniformly over your mesh. This is useful when quick results are desired. When dealing with sequences that don't have specific regions where you want more detail to be conserved, this is the best way to go.

Adaptive will analyze the motion of your mesh sequence, and focus bone density in the regions it deems most important based on the provided ruleset. (Area Deformation, Curvature , Velocity) The user can then use the "Primary" bones slider to control the number of bones in the focus areas.


Input Bones

The tool also allows you to feed custom bone positions through the second input. This allows you to build custom methods for determining where bones should be placed. Note that the tool will lock the transforms at the specified capturing frame.

Drawn Bones

The tool also features a really useful feature, where you can hand paint bones on the mesh to get very accurate placements. Simply select the tool in your network, and hit enter to go into painting mode. The tool will then show you strokes at the bottom of the tool, where you can also remove them again. To exit this mode, simply hit escape.


Error Visualisation

The "Error Visualisation" tab allows you to quickly debug regions on your conversion result that do not match the input mesh sequence. Green means it is identical, yellow is near identical, and red is off. 

The Converted Output field references the converted output mesh, which will be compared to the source using one of two methods. Maximum Error, and Accumulated Error. Maximum will show you the max error of all frames at any given time. The coloring will happen based on the error tolerance you specify. This allows you to configure how accurate the conversion has to be, and the tool will show you how close you are. The tool does not just color the mesh, but also returns attributes storing these values. This means you could automate the improvement process.

Accumulated error method will accumulate the difference of all points between source and result, also based on the specified error tolerance. Once again in world units.


COMMENTS

  • ztyqaz111 1 week ago  | 

    Very useful!
    Can i create bones from different topology mesh sequence?

    • ztyqaz111 1 week ago  | 

      sop_polydeform&SKINNING CONVERTER i found it!

      • Ambrosiussen 6 days, 18 hours ago  | 

        Hi!

        Glad to hear you found a solution!
        If you have questions, feel free to send me a DM.

        Paul

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