SSS in blender 4.0

globally

Hello, 

im looking for some tips on using subsurface in 4.0. 
at the moment I'm using a mix color in between the base map and the principal shader with a red hue set to a low value. I think I read somewhere that that's how sss works in 4.0. My issue is that with the distance set where I want it (0.009m) the eyelids turn white (I guess because they're so thin). If I set the distance to 0.004 the problem disappears but I no longer have a very strong sss on the ears and nose. How are others here setting up their sss? Should I mix in another base map with red where I want it instead of using a flat red color? Just increase the thickness of the eyelids? Or is there another way of doing sss in 4.0?

hope I've explained my issues well enough. Oh, this is on an 8.1 figure. I can provide more details if I've missed any.

 

thanks

Padone

You may try diffeomorphic with the extended principled option for materials, which gives you a good setup for daz figures, then tweak from there.

globally

Padone said:

You may try diffeomorphic with the extended principled option for materials, which gives you a good setup for daz figures, then tweak from there.

thanks. I take it that diffeomorphic is working with blender 4.0 and the new principaled now?

globally

Padone said:

You may try diffeomorphic with the extended principled option for materials, which gives you a good setup for daz figures, then tweak from there.

just so that I can understand what's going on, what would I need to do to solve this problem within blender? Is there a way of raising the minimum distance for example? Before the change over I believe you could use a math node to increase and decrease the radius. Would that kind of thing work?

Padone

Yes it works with 4.0 and the new principled. For explanation of the new principled there's plenty on google.

globally

Padone said:

Yes it works with 4.0 and the new principled. For explanation of the new principled there's plenty on google.

yeah i saw that video. i couldnt really relate what it taught to my issue.

globally

OK i now remember why i gave up on diffeo in the first place. I uninstalled the previous versions of diffeo and then reinstalled the newest version but i get the same error as i got before. Any ideas whats going on?

 

Traceback (most recent call last):
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\error.py", line 223, in execute
    self.run(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 287, in run
    self.loadDazFile(filepath, context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 153, in loadDazFile
    asset.build(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 89, in build
    self.tree.build()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 330, in build
    self.buildLayers()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 343, in buildLayers
    self.buildLayer("")
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\pbr.py", line 155, in buildLayer
    self.buildTopCoat(uvname)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 1232, in buildTopCoat
    self.linkScalar(spec0tex, top, spec0, "Specular0")
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 1989, in linkScalar
    node.inputs[slot].default_value = add+factor
KeyError: 'bpy_prop_collection[key]: key "Specular0" not found'
Error: Python: Traceback (most recent call last):
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\error.py", line 223, in execute
    self.run(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 287, in run
    self.loadDazFile(filepath, context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 153, in loadDazFile
    asset.build(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 89, in build
    self.tree.build()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 330, in build
    self.buildLayers()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 343, in buildLayers
    self.buildLayer("")
  File "C:\Users\check\AppTraceback (most recent call last):
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\error.py", line 223, in execute
    self.run(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 774, in run
    self.easyImport(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 783, in easyImport
    bpy.ops.daz.import_daz(
  File "C:\Program Files (x86)\Steam\steamapps\common\Blender\4.0\scripts\modules\bpy\ops.py", line 109, in __call__
    ret = _op_call(self.idname_py(), kw)
RuntimeError: Error: Python: Traceback (most recent call last):
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\error.py", line 223, in execute
    self.run(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 287, in run
    self.loadDazFile(filepath, context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\main.py", line 153, in loadDazFile
    asset.build(context)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 89, in build
    self.tree.build()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 330, in build
    self.buildLayers()
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 343, in buildLayers
    self.buildLayer("")
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\pbr.py", line 155, in buildLayer
    self.buildTopCoat(uvname)
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 1232, in buildTopCoat
    self.linkScalar(spec0tex, top, spec0, "Specular0")
  File "C:\Users\check\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\import_daz\cycles.py", line 1989, in linkScalar
    node.inputs[slot].default_value = add+factor
KeyError: 'bpy_prop_collection[key]: key "Specular0" not found'
Location: C:\Program Files (x86)\Steam\steamapps\common\Blender\4.0\scripts\modules\bpy\ops.py:109

globally

back to the original problem, i see that after some testing it seems to be effected by the eye geometry (as seen in the slightly horrific screenshot ive attached (SSS distance cranked all the way up to make it obvious)). id prefer to have the eyes in a position close to the lids so any ideas would be great.

 

cheers

Padone

For sss use burley in the global settings, since random walk gets leaking for non closed meshes as you noted, this is a known issue in blender for random walk and not related to diffeomorphic. For the python error please update to 1.7.4 and use the official blender version, not steam.

https://bitbucket.org/Diffeomorphic/import_daz/downloads/

Krys Kryngle

I have spent quite a few hours fighting with this issue.  The new 'Random Walk (Skin)' in Blender 4.0 seems to be a signifacant change from previous versions of Blender.  Older versions worked like Arnold and Pixar's Renderman where we could set the mathematical values for Red Green and Blue depth penetraion.  So red would penetrate deepest, then green, then blue, base on a mathematical formula.  With Blender 4.0, it seems that actual color inputs work best instead of the actual values.  So RGB inputs work better.  But, most importantly and most related to your issue, we need to bake out maps to reduce SSS in some areas.  The blender addon 'SimpleBake' will bake thickness maps which we can plug into the scale vaues, and then experiment with different color values (mostly deeper reds) into the radius values.

Singular3D

Krys Kryngle said:

I have spent quite a few hours fighting with this issue.  The new 'Random Walk (Skin)' in Blender 4.0 seems to be a signifacant change from previous versions of Blender.  Older versions worked like Arnold and Pixar's Renderman where we could set the mathematical values for Red Green and Blue depth penetraion.  So red would penetrate deepest, then green, then blue, base on a mathematical formula.  With Blender 4.0, it seems that actual color inputs work best instead of the actual values.  So RGB inputs work better.  But, most importantly and most related to your issue, we need to bake out maps to reduce SSS in some areas.  The blender addon 'SimpleBake' will bake thickness maps which we can plug into the scale vaues, and then experiment with different color values (mostly deeper reds) into the radius values.

Thanks, very interesting information. Seems that skin shaders have changed for 4.0+. I like the idea with the thickness map.

globally

Krys Kryngle said:

I have spent quite a few hours fighting with this issue.  The new 'Random Walk (Skin)' in Blender 4.0 seems to be a signifacant change from previous versions of Blender.  Older versions worked like Arnold and Pixar's Renderman where we could set the mathematical values for Red Green and Blue depth penetraion.  So red would penetrate deepest, then green, then blue, base on a mathematical formula.  With Blender 4.0, it seems that actual color inputs work best instead of the actual values.  So RGB inputs work better.  But, most importantly and most related to your issue, we need to bake out maps to reduce SSS in some areas.  The blender addon 'SimpleBake' will bake thickness maps which we can plug into the scale vaues, and then experiment with different color values (mostly deeper reds) into the radius values.

 

thank you so much for your response. I'm glad to hear it's not just me and that someone with more knowledge was having the same issue.

i think I understand the process you're talking about although I have zero knowledge of baking. I'm sure I'll find some tutorials on it. Actually I'm not entirely sure how I would plug the thickness map in to the scale values but maybe it'll make more sense when I'm sitting at my computer.

if you're the same Krys Kryngle from YouTube I’d like to say how useful I found your skin shader videos in the past. Obviously I’d love to see an updated blender 4.0 video but until then I'll bumble along by myself and see how things go.