Corona SSS and Daz3D People

[hitman60]

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.

[hitman60]

Corona SSS itself has nothing to do with texture tiling. It's more of UV/tiling issue than related to the SSS.

Such seams appear only while using SSS, as was mentioned above.

Corona is very good, but I cannot use it because of this :(

[hitman60]

Can you upload the scene and the assets here ? This way the devs will be able to reproduce this issue and give you an proper answer. https://corona-renderer.com/upload

Thank you.

It is done: 1541759113_SSS-Test.zip.

It happens in both skin shader and main shader with volumetrics ON.

[Beanzvision]

I can also confirm this issue. We'll need to investigate.

[maru]

I can also confirm this issue. We'll need to investigate.

It's a core issue. Already reported in our secret tracker, id=271549170

[Eddoron]

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.

[PROH]

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.

[hitman60]

It's a core issue. Already reported in our secret tracker, id=271549170

Hope this will be fixed soon, cannot wait to try Corona in full scale projects!

[maru]

Related threads:
https://forum.corona-renderer.com/index.php?topic=19163.0
https://forum.corona-renderer.com/index.php?topic=20714.0
https://forum.corona-renderer.com/index.php?topic=10364.0


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/index.php?topic=19163.msg134584#msg134584

[houska]

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/index.php?topic=19163.msg134584#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

[Beanzvision]

^^ 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.

[hitman60]

^^ 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?

[romullus]

Usually i set up material for Daz people like in attached screen. No seams and it's much easier to adjust single skin material than go through dozens of them and repeat the same changes.

[Sainsy]

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 :)

[draekser]

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