Hello!
It is possible to optimize Corona’s SSS or skin shader for models which have multiple materials with different textures connected together? Like people from DAZ 3D.
Be cause I got such lines/seams, at place where happens connection of materials with different textures.
Currently I use V-Ray in my work, and it doesn’t have such problem with DAZ 3D Characters.
It’s a core issue. Already reported in our secret tracker, id=271549170
Daz just has a terrible UV layout, imho. UV cuts should always be in non-visible areas or strong occluded ones. Oh…and clothes help too.
edited*
edi2* -seems to be a problem more prevalent in DAZ characters. The normal map seems to play the biggest role in all my other tests.
current workaround: Recut UV’s and/or reproject normals/regenerate using different dilation settings.
This is not UVW or bump/displacement related, and can’t be fixed this way. It’s all about Coronas SSS function. Different workarounds are found in another related thread, but they can’t always be used. This problem makes SSS unusable in many cases. So we need a proper fix.
Hope this will be fixed soon, cannot wait to try Corona in full scale projects!
Related threads:
https://forum.corona-renderer.com/ Corona's SSS behavior with multi/sub-object material and IDs
https://forum.corona-renderer.com/ Beta 2 Skin Shader Seaming
https://forum.corona-renderer.com/ C4D Seam Issues with SSS
There is a workaround by Nekrobul [3ds max]: instead of using 2 different material IDs directly, use a Blend material, connect the two SSS materials to it, and blend them using a mask (for example CoronaMultiMap). Will test and confirm if it works.
Another workaround: use CoronaMultiMap: https://forum.corona-renderer.com/ Corona's SSS behavior with multi/sub-object material and IDs #msg134584
There’s no CoronaMultiMap in C4D. The Variation Shader is missing the mask feature, so I guess the C4D solution would be:
Use Corona Layered Material and blend using masks
^^ Just tried a quick test using a layered material and this “seams” to be working so far. Next step is to do it with several materials and masks.
Can you please provide some examples how to use it on DAZ figures?
I solved this using the Corona Bitmap node, and set the UV tiling mode to Udim (do this first). Then select your daz image file (I found renaming them Diffuse_1001.jpg, Diffuse_1002.jpg etc.) worked a treat. It will then treat the whole area as one (from a SSS point of view) and load the corresponding map where required (so face, lips, ears is 1001, torso is 1002).
Hope this helps 
wtf ? it works perfectly… but I don’t understand how he can correctly replace the maps?
and thank you
Great tip! Saved my ass today
My pleasure - glad it helped
@Sainsy
it works. thank you
but not for me, I need materials that should be separated in C4D material manager for each ID\selection tag 
I did exactly that and it worked for me, needed to do this workflow on all materials that use sss and touch.
Does this was fixed in Final Builds?
