spz

[kazube]

Hiya!
Long time no post
SPzombie/WIP, sculpted and textured in Zbrush, decimated for Octane, PS's been used for merge 3 renders and signature, pure octane render, texture, specularity and bump maps.


The main problem is the skin shader, with glossy material and its energy on color surfaces. The bounced rays always strive to white or black with strong roughness.
Also reflection fresnel is still here, would like to have control over it. I found that control glossy material through map is a bit tricky, in general.

The 2nd problem: insufficient energy through glossy materials. The inner part of eye has the same material as teeth, but as I mentioned already, the lighten material is losing its energy power to easy.


These problems may be the result of my lack of knowledge and just don't know how to do it
Hope You still like it.

[Chris]

Awsome sculpt and paintjob

Cheers,

Chris

[radiance]

Hey,

The glossy material uses a physically correct BRDF for layered paint/varnish type glossy surfaces.
Therefore it's not always correct for these kinds of materials...

Manual control over fresnel kinda breaks the physically based philosophy of the engine, and would produce a lot of completely wrong results with the untrained... therefore it has'nt been on high on our priority list, but we'll definately add it in the near future.

In general it looks (in the top renders) there is too much glossyness in general. The skin looks more like plastic than the dried up zombie flesh from films...

Radiance

[colorlabs]

Hi radiance,

I'd love some light reading on the physics of IOR and reflection and fresnel and all that.

Using Octane has really changed the way I see the world and I want to know more about light and materials now.

A big question I have yet to figure out - what's the difference between silver and gray? Like the rough side of aluminum foil vs. a gray shirt. Why do people always draw mirrors as gray or light blue in cartoons? I could go on and on.

Anyway, are there any books or articles you could recommend, just in general about how light reflects and refracts thru various surfaces?

Thanks!
Keith

[kazube]

@Chris .Thanks, glad You like it.
@radiance.

The glossy material uses a physically correct BRDF for layered paint/varnish type glossy surfaces.
Therefore it's not always correct for these kinds of materials...

Manual control over fresnel kinda breaks the physically based philosophy of the engine, and would produce a lot of completely wrong results with the untrained...

If so, what kind of materials were the point of reference to determine the smallest value?
Simple Test scene: sphere with black specular material. Slider goes to zero.

Now, lets try to add strong roughness.

...and try to achieve something looks like a skin.

The specularity of this material is still to high, but adding more roughness causes a black contour.

therefore it has'nt been on high on our priority list, but we'll definately add it in the near future.

Wish You consider a new organic material, skin, I'd be more than happy.

In general it looks (in the top renders) there is too much glossyness in general. The skin looks more like plastic than the dried up zombie flesh from films...

Yup, You're right. Consider it as a WIP; there is more specular than it should be for better matching between diffuse and bump map . On glossyness matrials i can see more.
P.S. Don't get me wrong, I like octane very much. Tried many stand alone-renderers, only octane suits me with its non-cg-hittin-my-eyes-look, most analog-looking engine out there in my humble opinion. Thanks for Your hard work.
Best Regards
k.
edit: repeated sentences.

[kazube]

some updates. WIP.
Still trying to achieve SSS and human skin shader.





Best Regards.
k.

[ello]

really gruesome end impressive work! i like that one with the dark skin

[cornel]

wow. That´s an awesome charakter! thumbs´s up! I absolutely love him!

regarding the SSS:
There´s no chance (as yet) to achieve 100% believable skin without light scattering in the volume. You know that.
But there might be a simple way to increase realism by adding a strong rim light e.g. by placing extra emitters behind. In conjunction with high contrast camera response presets like Ektachrome or Kodachrome this should boost your skin´s colors including the reds.
(like real SSS-skin has a redish tone in its terminator - the veins- so make sure your texture includes enough of it).

If that fails in looking good, what about a wet/sweaty skin as an alternative?
Glossy but with nearly no roughness? With more light being directly reflected, there should be less need for SSS - as less light is entering the volume.

[radiance]

@Chris .Thanks, glad You like it.
@radiance.

The glossy material uses a physically correct BRDF for layered paint/varnish type glossy surfaces.
Therefore it's not always correct for these kinds of materials...

Manual control over fresnel kinda breaks the physically based philosophy of the engine, and would produce a lot of completely wrong results with the untrained...

If so, what kind of materials were the point of reference to determine the smallest value?
Simple Test scene: sphere with black specular material. Slider goes to zero.

Now, lets try to add strong roughness.

...and try to achieve something looks like a skin.

The specularity of this material is still to high, but adding more roughness causes a black contour.

therefore it has'nt been on high on our priority list, but we'll definately add it in the near future.

Wish You consider a new organic material, skin, I'd be more than happy.

In general it looks (in the top renders) there is too much glossyness in general. The skin looks more like plastic than the dried up zombie flesh from films...

Yup, You're right. Consider it as a WIP; there is more specular than it should be for better matching between diffuse and bump map . On glossyness matrials i can see more.
P.S. Don't get me wrong, I like octane very much. Tried many stand alone-renderers, only octane suits me with its non-cg-hittin-my-eyes-look, most analog-looking engine out there in my humble opinion. Thanks for Your hard work.
Best Regards
k.
edit: repeated sentences.

This is how our glossy BRDF works, as said it's meant for varnished / substrate type surfaces, not meant to be used for skin.
It always shows glossyness, even with the specularity set at 0.

A way you could try to add a pseudo SSS like effect is to use diffuse transmission.
Create a diffuse material node and connect a colour to it's 2nd (unconnected by default) input, to turn it into a diffuse transmitter.

If you place another mesh inside with a dark grey reflectance and reddish diffuse transmittance,
it could work, provided you can place a mesh inside that is say 1-2 milimeters below the surface (like a russian matroska doll)
Even more than one (in the matroska doll way) could make a better effect still.

Until SSS comes along, this is the best alternative at this time.

Radiance

[kazube]

@cornel. Thanks for the tips, were very helpfull. Adding an extra back rim light and some small corrections in the spec map seems kinda work.
Ektachrome's and kodachrome's tint is too redish for me.
@radiance

A way you could try to add a pseudo SSS like effect is to use diffuse transmission.
Create a diffuse material node and connect a colour to it's 2nd (unconnected by default) input, to turn it into a diffuse transmitter.

It's the best way for SSS so far in my humble opinion. Tried mix off 2 materials, glossy and specular controled by floatimage but results were not sufficient.
After some tests, I think, I am able to control SSS in a custom way. Now only thing about to care is a small vein one the earlobe, still working about it.

If you place another mesh inside with a dark grey reflectance and reddish diffuse transmittance,
it could work, provided you can place a mesh inside that is say 1-2 milimeters below the surface (like a russian matroska doll)
Even more than one (in the matroska doll way) could make a better effect still.

Need a check this out, thanks for the tip.

Until SSS comes along, this is the best alternative at this time.

Cant wait
@ello Glad You like it.
Best Regards
k.