| On this page |
This workflow covers how to transfer muscles from one character to another. The Test Geometry: Otto Muscle Transfer recipe is a good template to do this. This page covers the broader workflow requirements and useful nodes created specifically to make this process easier.
Deflate SOP on the cow’s skin to prevent the transferred muscles from extending into the shoulder hump, neck, or belly.Required assets ¶
The source character is the character with existing muscle and bone geometry which you want to transfer from. The target character is the character which you want to transfer the muscles and bones to.
-
Source Muscles - The muscle geometries of the source character.
-
Source Bones - Anatomical bone mesh associated with the source character.
-
Proxy Source Skin - A low resolution version of the source character’s mesh for more efficient topology transfers. See Preparing your geometry for more information.
-
Proxy Target Skin - A skin mesh that matches the proxy source skin in topology. See Preparing your geometry for more information on how to transfer topology between characters.
-
Target Render Skin/Mesh (optional) - The final high resolution mesh or skin used in your production. This isn’t required for the muscle transfer itself, but is recommended to use as the rest skin input for tissue creation with the
Tissue Solidify Otis SOP. If you plan to reuse the source character’s muscle setup on the target character, transfer or recreate any required groups or attributes from the source skin on the target skin.
Tip
If you don’t have a source character with muscles and bones and your target character is a humanoid biped, you can use the Test Geometry: Otto Muscle Transfer recipe and replace its example target character with your own. For best results, use the nodes described in Important nodes to match your character’s physique to Otto’s before transferring the bones and muscles.
Preparing your geometery ¶
There are a few key steps and concepts to understand when preparing your geometry for muscle transfer:
-
The muscle transfer relies on matching topology between the proxy source skin and proxy target skin. You can retopologize your proxy target skin using the
Topo transfer SOP or other external tools. -
The proxy mesh refers to the low resolution proxy source skin and proxy target skin used in muscle transfer. This allows for a faster topology transfer instead of using a production quality mesh. The render mesh refers to the final high resolution mesh or skin used in your production. For the muscle transfer process, only the proxy mesh is required.
-
You don’t need to match the scale size for the proxy source skin and proxy target skin. The muscle transfer recipe will automatically handle it and scale your character back to its original dimensions in the final output.
Important nodes ¶
|
Transfers muscle and bone geometry between characters. The recommended workflow uses one Muscle Transfer SOP to transfer the skeletal bone geometry, then a separate Muscle Transfer SOP to transfer the muscle geometry, with the transferred bones connected to its third input. |
|
|
Moves points around so the edges between them match those specified by the second input. Without this, areas with bunched up edges in the target mesh compared to the source mesh will cause the transferred muscles or bones to be bunched together accordingly. |
|
|
Helps remove volume from fleshy regions such as breasts, bellies, or buttocks that you don’t want to be filled with muscles. You can use this on either the source or target skin before they are input into a |
|
|
Slides geometry from one region of a surface to another guided by curve-based landmark pairs. This can help adjust the position of muscles or bones. You can use this on your target skin before you input into a Muscle Transfer SOP. |
|
|
Takes a template mesh and non-rigidly deforms it to match the size and shape of a target mesh. This can retopologize your proxy target skin to match the proxy source skin. |
Edge Relax SOP
Attribute Paint SOP
Topo Slide by Curve References SOPTip
Instead of modifying the target mesh directly, a better approach is to store all adjustments in a separate targetP attribute, using a 
Rest SOP. This allows the target character’s unmodified shape to remain visible for reference, while the 
Muscle Transfer SOP uses the modified target mesh for the transfer. This allows you to get a more accurate sense of the final position of the transferred bones or muscles, relative to the skin.
Next steps ¶
After you have transferred your muscles and bones, you can move on to the Muscle setup.