I’m looking for some advice on morphing rigged characters. A similar questions was asked on this site in 2010 ("figure mixing" or morphing between rigged characters) so I’m wondering whether there have been any developments since then or whether anyone has any new insights/ suggestions.
To recap the problem with a hypothetical example: let’s say that I have two characters - a child and an adult. Their mesh surfaces are in the same pose and are already in correspondence so they have identical topology and I can simply apply one mesh as a shape key to morph between them.
Now let’s say that both characters are rigged with armatures that are identical in structure (e.g. number of bones), but differ in bone lengths/ joint locations. Do I need to morph the armature as well as the mesh in order to be able to pose/ animate intermediate morph characters? If so, how can I apply such transformations to the armature?
The easiest way to specify pose independently of the armature’s bone lengths is to specify the angle between connected bones at each joint rather than the location of each joint, since the latter is affected by both pose and bone lengths. I believe this is how mocap data is processed, so that -for example- Andy Serkis’s mocap data can be used to animate Gollum/ King Kong/ Caesar - characters that have different skeletal proportions to him.
Is there a straightforward way to achieve this in Blender? Writing a python script/ add-on to achieve this is going to involve a lot of trig! Any suggestions welcome. Thanks!