Shader options with octane render engine

Chris Fox Art

With this topic i would like to collect experiences with the Carrara and octane shaders on the octane render engine.

I know that you can set octane shaders but i am still not that familar with them but like to play around with them sometimes, so i found out yesterday while playing with the cloth shaders and shadow catcher option with a diffuse octane shader you can create stealth clothes lol that could be interesting in creating a stealth suit.

What i've found out is that a few normal shader options doesn't have any influence on the render, so they are not really supported with the octane render engine and are not needed.
But some shader options have a big influence on other shader options, for example the bump option have a big influence on the shine option.
I often use highlight, shine and reflection for a wet or glossy look, like the lips sometimes or a scene where the character is sweating.
But if you than turn up the bump the glossy effect will disappear.
Another interesting part of this is refraction, because if you turn refraction off while using reflection you will have a funny looking effect on the body parts.

The Subsurface Scattering has no effect at all, the same about Translucency.
The transparency will just make the body part black but thatswhy there is the opacity option.

Picture one is a mix of normal shader and octane shader with a diffuse channel and shadow catcher.
The second picture have opacity set to 0,950 to get it a bit transparent.

The third image have no bump but 100% highlight, shine and reflection and it got a nice glossy look.
The fourth image still have 100% highlight, shien and reflection but also 100% bump on the lips and the glossy look is gone.
The last picture was just turned off the refraction, so we've got chrome lips. With no bump on the lips than you will get some nice flat chrome lips with no details lol.

So i am wondering, is there any way to combine a nice glossy look with bump on an octane shader?
What about your experiences with normal shaders and octane shaders and rendering with the octane engine?

Chris Fox Art

This image have still 100% shine, highlight and reflection but only 15% bump, as you can see there is still no glossy effect on the lips but there are areas that shows something like a thin film over the lips that looks a bit unnatural.
Turning down the reflection to 25% - 50% is the best way to solve that problem but the question is, how to combine glossy and bump together?

PhilW

When using bump with reflection, it isn't changing the reflection itself, but it is breaking up the reflection. If you imagine a small bright light on a mirrored surface, you will get a sharp relection of that light forming a specular highlight. If that mirrored surface now becomes bumpy, the reflection will be broken up and effectively become a more diffuse reflection - light is still being reflected as before but it will not be as sharp and clear, and this is what is haoppening in Octane.

If you turn off Fresnel in an Octane glossy material, you get very shiny metallic surfaces.

Chris Fox Art

Thanks a lot for the explanation.
Where is the fresnel located? Can't really find it.

PhilW

Sorry it is just IoR (Index of Refraction) which gets converted to the same in the Octane Glossy material. if IoR is 1.0 then you get "perfect" reflections, ie. independent of the angle of incidence, which is more typical of metals. Most other materials should have an IoR higher than 1.0, which adds a fresnel effect, ie. the reflection is higher at the edges than for faces that are facing the camera. A good example of this is to look at most bathroom tiles - if you look face on there is hardly any reflection, while if you look very obliquely you will probably see quite clear reflections.

Chris Fox Art

Ah i understand, thank you very much, i will try this out :)