OTOY Forums

Happy July Fourth to U.S. forum visitors! I downloaded the Win64 Octane demo for LightWave 2019.0.3 and am having a devil of a time evaluating it. Two problems:

1. What Octane material models a frosted translucent material that scatters light passing through it? I cannot figure out how to create an Octane material that works the way Principled BSDF does in LightWave. No matter how high I crank up the roughness, the best that I get is an object of some degree of transparency, and I'm able to clearly and sharply see the black body light source behind the material, when what I was expecting to see was a diffuse, indistinct glow from the light emission source. Think of a frosted light bulb, which is essentially what I'm trying to model. You see a diffuse glow in the center of the bulb where the filament is, but you don't see the actual shape of the thin filament when you're looking at the bulb.
2. I don't have a backdrop turned on in the scene I'm evaluating, but there is an actinic bright white environment light or white background in the scene that is way over-lighting everything and blowing out the Octane textures I'm trying to evaluate. The object in my scene is a spaceship floating in the void, but not only is the background not black, there is scorching flat bright white light everywhere. Is this just part of the demo overlay or is there some way to turn this off? (If this is intentional, it makes it very hard to evaluate Octane.)

Thanks!!

Aaaaaand never mind! I figured out both problems.

1. For the translucency issue, I figured out that I needed to use the Octane Specular Material node. The "Ward" BRDF model seems to give the results closest to what I was trying to achieve. Getting just the right amount of light to pass through from the light source behind the specular material without the light source looking too sharp or the light strength getting washed out took some back-and-forth fiddling between the strength of the texture emitter and the refraction, dispersion, roughness, and opacity settings of the specular material. (Interestingly enough, negative dispersion coefficients seemed to work!) I finally settled on an IOR of 1.1, a dispersion of 0.0, a roughness of 1000%, and opacity of 100% (which is bizarre but it works), in combination with a diffuse material light source that has an input texture emission node set to power = 25.0.
2. For the backdrop and lighting issue, DUH that was on me for not RTFM first. I tried setting up a scene without touching the RenderTarget node... D'OH! After some poking around I got my environment set up exactly the way I wanted it.

I am stunned by the speed and accuracy of Octane Render (once I figured out the required settings!). Now if only OTOY's danged online shop would work, I'd sign up for a subscription! (An email requesting help has already been sent to the OTOY help desk.)