I happened upon Chris Jones’ Human Progress thread the other day, and now I’m experimenting with facial animations again.
See:
**The above animation was done with shape keys on a mesh with a multires modifier.
Reading Chris’ thread from post one, I soon realized it would take some time to read through the entire thing and properly absorb the information, so I took a break from that around the point where tension mapping is being discussed. Later, I searched for information on tension maps in blender and found this Bad Normals tutorial.
I modified the geo-nodes setup in that video to get this:
** Currently this is only a visualization of the changing of the area of mesh faces due to the influence of the shape keys.
I am using a duplicate mesh with no animation to get the initial face areas, I capture and sample that information in a geo nodes node group attached to the animated mesh. Do a bit of math with the face areas from the animated mesh and the base, feed it into a color ramp, output that color, then use an attribute node in the shader to apply it on the mesh.
You can download an example with my tension geo-node node group below – it uses tubes from curves like BN’s:
TensionExample.blend (blender version 3.4) (923.3 KB)
[EDIT]
Forgot to mention that I retopologized my Paul Rudd head using speedretopo.
The wireframe:
