Jump to content

SSS - Shader in H11


sanostol

Recommended Posts

Hey that's looking good!

I'd be very keen to find out what lighting setup was used in the tutorial, as I have personally found the SSS shader in Houdini to be pretty good, but (as one would expect) it is highly dependent on the lighting setup. I'm always interested in how others set their lighting up, and more so now that I have been using PBR exclusively for a while now.

I look forward to seeing more of your progress!

Matt.

Edited by Matt_K
Link to comment
Share on other sites

w6rue0.jpg

this process is a study in splitting hairs...

lol

the diffuse layer is not where i would like it. the fine details, sun spots etc, are not showing up.

pic on the left is my progress, pic on the right is the provided adv. skin stage.

the big diff. here is lighting. the post post was a simple pair of point lights in key and fill positions.

in the lessons, he used maya portal lights for key and fill. now i have here. very odd ducks those lights.

using a natural sky, with a portal setup, with SSS and pbr rendering made a huge diff.

still too yellow. oh and am having a devil of a time with zbrush 4 normal maps. houdini doesn't seem to like tangent info inthere.

the mantra uber shader defaults to including the 'base color' for the attenuation and subsurface colors. i had to dive in and promote the toggles on both of those.

next, i have to add texture maps to the diffuse 'roughness' , specular 'intensity' , specular angle.

lastly, under the reflect tab, i had to determine the nature of the reflection mask vs the specular map. even though the reflect lights and reflect objects are tied together in some aspects, their masks are separate. the reflection mask limits object reflections and the specular 'map' limits light

reflections.

Edited by smaugthewyrm
Link to comment
Share on other sites

  • 1 month later...

I might have to check that DVD out.

I hope people are still trying to crack this nut.

I spent a while tweaking some settings and reading over the the help docs.

This is an old version of a model i was working on, so its pretty low rez. There is no spec and the colour map was experimental to say the least. It was done with polypaint in Zbrush. There isnt much detail if any in the map. And the eyes have no maps on them either.

But i think its possible.

Saturated Version

skintest_c.jpg

Cooler (prefer this one a little more)

skintest_outb.jpg

Edited by phrenzy84
Link to comment
Share on other sites

hers a quick test i did with lees headscan http://www.ir-ltd.net/ to compare mantra and modos shading with environment light.

its nothing tweaked, just plugged one map, env and rendered..both behave pretty similar i think, and are consistent under diffrent lightings..

mantra

post-4775-130147445588_thumb.jpg

and modo

post-4775-130147448143_thumb.jpg

Edited by theflu
Link to comment
Share on other sites

Yeah i should try using lee's asset. I think its becoming a bit of a benchmark :).

In terms of the SSS, any specific settings? Your results i would say are better than modo's (IMO).

ie did you hookup the texture to the diffuse color or subsurface etc?

Edited by phrenzy84
  • Downvote 1
Link to comment
Share on other sites

Cheers mate. Yeah that sped it up quite a bit.

Using PBR with a hdri is awesome. Forget my poorly lit renders. (Though it makes me want to really get into lighting).

What are your attenuation settings like? Color and density? Is everything at default? Oh and where did you get those environments, they have some pretty decent results.

Link to comment
Share on other sites

just play with it and see what it does, depends alot on model and scale.

its good to first disable all but sss channels, to see what going on. give a col to attanuation and tweak its density till its fits the size of your model.

then you got to balance the hue/brightness between subsurface and attenuation color. also subsurface quality usually needs more samples.at last turn in a little diffuse, i usually end up at sth like 0.2 for diffuse amount.

but beware that your maps for subsurface (thats where my color map goes) and reflection/fresnel settings count a big part in your skin appearance too.

hope that helps!

( then envs are from hdrlabs)

Edited by theflu
Link to comment
Share on other sites

Yeah for the workflow ive been turning everything off and work on one thing at a time. With attenuation, i have had mixed results. Not sure i fully understand how it works (regardless of the docs), but I have some feeling of what i can expect.

Here is how far ive got so far. Had to cover the eyes but they were working when i did them on their own but with the rest of the model they now no longer work. Might have to do with raytracing since there is a transparent/refracting object im working with.

pbrbump1re.jpg

Link to comment
Share on other sites

  • 1 month later...

to speed up the sss You can dive into to shader, unlock the surface shader model and jump into the surface shader. there look out for the sss part and dive into the if1 node, now in the physical sss turn on the optimize secondary rays checkboxes for single and multiscattering. it helps a lot to speed up this

Wow, that just isn't a little bit speeding up, it's blistering fast now.

Thanks a lot for pointing this out.

  • Like 1
Link to comment
Share on other sites

Another common place to experience slowness when raytracing is displacement. Older versions of the Mantra Surface material would still run displacement even if it wasn't displacing at all. Adjust down the Ray Shading Quality on your object -- like to 0.1 or so. Raytraced displacement shading against polygons seems to always be overly aggressive for most types of displacement.

Link to comment
Share on other sites

  • 1 month later...
  • 1 year later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...