Again, the problem is not exclusive to daz.
Your setps are pointless to anyone who can reproduce the same light behaviour by applying any type of morph target to a skeletal mesh.
If you activate the morph under a light source with shading you’ll see some sort of shading artifact.
The same way you correct the shading behavour for that, is a valid way to correct the shading behaviour on any other skeletal mesh with morph targets - including a daz character.
If I’m not mistaken, JCM is literally just a morph target (blender shape key) which is directly controlled by a joint.
literally something we have used in the industry for years, that got a fancy acronym in Daz. Joint Controlled Morph?
its not some hocus pokus black magic that only a Daz export can create.
Make a blender 1m cube. Tab edit mode. Move the top to 1.5m so as to get a 2m tall rectangle. add a loop cut horizontally. Go object mode and add a subdivision modifier of 10 and apply it.
you should get a box with vertices every 10cm or so.
extremely low poly and easier to debug.
unwrap the rectangle with a standard box cut. Just so we actually get seams to check the shadowing on those too. The character has them in different areas, but still has them. Its good to debug.
Assign an empty material, just so unreal doesn’t freak out on import (which it shouldn’t anymore anyway).
while at it, select the whole mesh in edit mode and set faces to smooth.
Make an armature.
Add the base bone and stretch it to .5m so it sits at the middle spot of the original 1m cube.
Extrude a second bone to 1.5m so the box has 2 bones.
Move the botton of the bottom bone down to -.5m so that the whole box is covered.
Parent with automatic wrights.
Tab into pose mode. Bend the top joint by 45deg so you have a bent area to work on.
Now split. export and import into engine without a morph. This will be the comparison mesh.
Don’t forget to use the appropriate Faces smoothing group option
after export add a shape key base, and a shape key. Modify/adjust the shape with either push or pull and the automatic distribution.
Since the idea is to generate an armpit corrective probably pull inwards creating something that resembles a hole.
save it out/export and import in engine. Make sure morph is checked and all of that.
Make a blueprint, expose a float. Use the float to power the morph target of the skeletal mesh.
have it work on construction script if possible, so you won’t need to simulate.
When you alter the morph you will see how the engine acrually behaves with base lights on a morphed skeletal mesh.
you can use this cube to debug possible solutions.
because of very low poly it will be more subject to artifacts.
Also, since it literally takes me longer to write this then give you an engine ready cube, I’ll post one in 10 or so.