Hey folks,
Every time I try to employ volumetrics in Octane I give up and move onto something else. I can no longer keep ignoring this feature, though. After a dozen or so attempts and hours of reading/watching tutorials on octane volumetrics, I am convinced that scattering/absorption is the least intuitive aspect of this powerful renderer. Like why is there a thickness and a density slider? Some tutorials on brograph show settings like scale, that seem to be just what I'm looking for, but for some reason do not exist in the later builds. I have tried every combination of parameter from render settings down to absorption , phase, density, and volume step length. Nothing I try achieves the one thing I am going for, the main reason anyone would use volumetrics: volumetric shadows. I'm talking about those gorgeous rays of absent light caused by gobos, branches, or anything between the light source and the floor. I have included a scene that demonstrates the problems I am having. The attached images demonstrate my failure achieving the desired effect with both a fog volume and with a sky object medium. You can see I am getting a nice bit of atmospheric depth in the image where I have used the fog volume, but no rays for some reason.
Please could somebody just open my project, make whatever adjustments are needed to produce the rays of shadow and then tell me what they adjusted exactly and why. If you are feeling super generous you can solve the issue in sky-based fog volume as well, but for now I would be satisfied just to know how to get what I'm going after with a scaleable fog volume.
Before you suggest it, yes, I have downloaded and examined the scenes in Ahmet's sample pack, like the graveyard with daylight and volumetrics, but no amount of scrutiny is helping me understand which settings are doing what. I understand this topic has been beaten to death, and that there are SO many posts about it and cries for it to be demystified (no pun intended), but nothing I have read or watched has corroborated any single, dependable, approach to setting up volumetrics for predictable results. The sheer number of posts out there asking for help with this feature is evidence to me that the concept is too difficult to educate users on by just linking example scenes. We need a real discussion about these sliders!
Thanks for your time,
Ben Matthews