Octane shader settings for realism
Chris Fox Art
Posts: 380
I was/am now playing around a bit with the Octane shaders to find a setting for natural and realistic skin textures.
There are a lot of very detailed and realistic portrait renderings around the net, most of them was done with different software and render engine like V/MentalRay
(Here are a few examples what i mean: https://www.cgtrader.com/blog/portraits-of-the-21st-century-the-most-photorealistic-3d-renderings-of-human-beings)
I know that they use different maps to achieve this kind of realism and i am wondering if Octane with Carrara is capable of this but i don't know why it shouldn't be possible to get similar results with Octane.
Thatswhy i would like to use this topic to collect, share and discuss different settings for octane to find out the best settings to get out the best results.
From what i know is that there are a few very important points to get great results.
The first point is: Textures. If the textures aren't natural, than the outcome won't be that natural. (Found out that a lot textures looks very soften and have no real skin details in them, like most textures with makeup and the figures looks more like dolls than real people why i often prefer just the natural textures without any makeup).
The second point is the lightning. I often just use HDRI images for lightning but i know that sometimes an HDRI isn't enough, but it's not always easy to get a natural light source.
The next point is modeling. A natural human is very often asymetric but that's more a thing about the morphs or model room but a few things can be achieved with the bump or displacement maps.
So the important things i would like to focus on now are just the shader settings.
I guess there is no direct answer that exactly this value on these shaders are the best as it is always a matter of the scene.
For example, a render inside a room needs different settings than a render outside of a room, just with an HDRI for example but this could give a direction where to move.
In this image i've made the Octane Materials as a Mix, Specular and Glossy (default was just glossy i think) but i am still not happy with the results.
Anybody knows if there is a way to use SSS Shaders and translucency? The normal Carrara SSS and translucency seem not to work with Octane.
Any shader settings are very welcome! :)
i will post my shader settings after trying a few things.
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Hi Chris, I have attached an (zipped) example of my formula for Octane skin, I am not claiming it to be perfect but I think it is pretty good and it includes SSS effects. It is basically a mix between a Glossy material and a Specular material, with the later providing the SSS with the Medium set to Scattering. Feel free to play with the settings, you will need to change the textures anyway (the example is based on Olympia 6 textures) and different textures often need subtly different settings to work best. One of the great things about Octane is that you can see the results render as you make the changes, meaning that it is usually easy to tweak to get the results that you are after.
I hope this provides a good starting point for your investigations and if you produce any significant improvements, let me know!
Here is a rendered example.
P.S. You must use either Pathtracing or PMC for the SSS element to work, it does not register with the Direct Lighting kernel.
Hi Phil,
thank you very much for the shader, i will test it out.
The first image is with normal Carrara Shader, the second was converted to octane and got some settings (specular and glossy mix), the thirs one just got's a bump map. Looks like the eye got another pair of eyelids lol.
The fourth image was made with your shader, just played a bit around with the settings. The last image i've made yesterday, was without displacement.
Octane Environment Power is set to 2,200, with the hdri added i've set it to 3,200,
I didn't changed much, just Film IOR, Index of Refraction to about 1,950 and Roughness, Film Width to about 1,000 and added a normal map to the image.
added an hdri to the scene, Pathtracing and PMC won't make a big difference
while doing a lot of tests in octane with scene settings, pathtracing, light settings and playing a lot with the shaders (also tried a specular and a diffuse mix) i thought i should try something else.
So i changed a bit the textures with Lightroom but still didn't got the outcome i wanted so i thought i should think in a different direction.
I took a look on one of the renders (the first image) and asked myself what i don't really prefer in this one.
The render is nice and looks pretty detailed and realistic but what i didn't prefer was that the contrast is a bit to high for my taste, so i put the image into photoshop and just reduced the contrast about -15 and the outcome was the second image which looks a lot more natural from my point of view.
So the first thing i've done now was reducing all the textures i am using for this character to -15 contrast and tried another render which you can see in the third image.
The fourth image is the same render settings with the normal contrast textures and i've found out two things.
The first thing is that Carrara/Octane seem renders with a very high contrast, so that should be something that can be changed in the render settings or maybe just in the shader room?
The second thing is that every scene setup will work different, so in the first image reducing the contrast to -15 was ok but with an hdri image as scene background, lowering the contrast to -15 won't give the same results.
Oh, and i've nearly forgot, in the first two images is no depth of field in the camera settings, the third and fourth have depth of field enabled.
So for a more realistic render i would deactivate depth of field or would add that effect in the post work.
Just the fourth and third image again without depth of field, left is with low contrast and right with more contrast.
The zip file have the shader settings for the face.
@PhilW i've saved your render and reduced the contrast by -20 and find the outcome pretty interesting what a small change can do.
Just like to add this, i've took a few other render i did the last days to photoshop and tested two things out which both worked good.
The first thing is, reducing the contrast to from -15 to -20 is a good way to get a more natural look at the skin.
But there is another way in photoshop, changing the gamme set from 1,00 to 0,60, the image gets very bright but anything between 1,00 and 0,60 works fine.
Haven't tested a mix of both yet but that lead me to the topic about the gamma correction in carrara and somehow it seems that octane doesn't do any changes if you change the gamma correction in the render room of carrara. I did a render in octane with gc of 2.2, changed the gc to 3.0 and did the render again, couldn't see any difference.
The same when i changed the gamma correction in the color correction, it restarts the render but can't see any difference.
Changing the contrast (or gamma) on a texture will not give you the same results as changing it for the final rendered image, as the latter includes the effects of the lighting. Octane does not have a "contrast" control per se, but it does allow you to change the gamma of the rendered image, the control is under the Imager tab in the Render Target window.
If you are using my skin material, it includes the effects of Sub Surface Scattering and that is only rendered by one of the true photorealistic renderers - Direct Lighting is fast but is more like rendering with the Ambient Occlusion mode in Carrara and it does not calculate the effects of SSS. So to get that, you have to render with either Path Tracing or PMC - both will converge on the same image eventually, PMC will converge faster with a complex lighting setup, even if it seems to start slower.
Depending on the textures you are using, you may need to adjust the SSS settings in the second material (in the Medium/Scattering section). You can also adjust the balance between the diffuse and specular, it is useful to isolate each in turn to see what is being contributed by each.
Here is a darker skin example using Darius 7.
Thanks a lot for the information! The Character looks pretty good.
Now i'm testing out all the response in the imager and there are a few pretty nice, i also test a bit with gamma there.
The Scattering means how deep the light comes through the skin right?
I am thinking about exporting the full scene to octane to work just there as i like the interface a lot more than from carrara..
Just one issue, dynamic hair won't work in octane standalone.
There are a number of parameters that you can adjust under Scattering. Density controls how deep the light will penetrate, the Absorption and Scattering colors will both effect the final coloring of the effect. Don't forget that Transmission will also play a large part as that can color the light as it enters the medium.
@PhilW Both renders was with the shader u've send me, just did some adjustments, reduced the bump power to 0.200, added a normal map, a bit of displacement and i changed a bit the absorption and scattering to a more greybrown color and added an emmission rgb texture map.
The only difference from image one and image two is that i've added custom eyebrows and decent bodyhair to the second image, so that the eyebrow doesn't look so flat and you can slightly see the difference on the jaw that there are very fine hairs now (but they are all around the head except the eyes, eyelash and lips).
Brows are 0,03ft, thin and have a scale of 3.0 while the bodyhair is 0,00ft (i've done 0,001 so very short), thin and scale of 1,75.
Both have your octane material applied, brows have black while the body hair gots ashblonde.
in the assemble room the body hair looks really funny as it is displayed very strong there while the render is very soft.
Image 3 is without depth of field
Just wondering, Carrara have a nice natural pattern function for Cellular but this won't really work in Octane.
Is there any way to use this function in Octane too?
You could try rendering a cellular pattern and using that as a texture map. Or use Inagoni's Baker plugin to produce a specific map for your model.
normal carrara shader, texture as bump map, tile 4x4, seamlessly, bump in the top shader is set to 20%.
One image rendered in Octane, the other in Carrara native (same settings).
Needs a bit more adjustment as i also applied it to all face shaders, maybe 5x5 tile size and bump set to 10 - 15 should be enough.
Pretty interesting working with these.
You're doing some great experiments!
This image is with normal bump map
The second one with cellular bump map in the specular section from octane material.
Tile size is 6x6, seamlessly and Power set to 0,050 as a little bump is enough.
Next time i will change the lips bump as the lips won't need this cellular bump :)
The difference is hard to see but with some zoom on the image there is a small cellular texture visible.