Hi, in 3delight renderer volume shader has a multiple scattering parameter that greatly changes the perception of volume and makes it possible to visually make clouds out of smoke.

I tried to increase the volume limits to high values of 64 or more in the convergence variance mode, but this slows down the rendering process a lot, I know that the technique of using indirect lighting to generate photon maps from lighting helped earlier in Mantra, which gave a significant speedup later and was more looks like the desired result.

How can this be achieved now in Karma and is it possible given that indirect light sources are not supported by Karma?

alexwheezy
Hi, in 3delight renderer volume shader has a multiple scattering parameter that greatly changes the perception of volume and makes it possible to visually make clouds out of smoke.

I tried to increase the volume limits to high values of 64 or more in the convergence variance mode, but this slows down the rendering process a lot, I know that the technique of using indirect lighting to generate photon maps from lighting helped earlier in Mantra, which gave a significant speedup later and was more looks like the desired result.

How can this be achieved now in Karma and is it possible given that indirect light sources are not supported by Karma?

I don't know of any renderer that produces multi scatter results comparable to 3delight without hacks to fake it, other than scientific or proprietary ones like Mitsuba. Mantra got close but it always needed some kind of hack like two lobes or reduced shadow density and it was ridiculously slow. Photon mapping made it quicker, but you might as well use a baked lighting volume which would work in karma too.

Thanks for the reply, I'll try to figure this out. I had an idea to apply Pyro Bake Volume using a scatter field to simulate the same effect as in clouds with multiple scattering.

alexwheezy
Thanks for the reply, I'll try to figure this out. I had an idea to apply Pyro Bake Volume using a scatter field to simulate the same effect as in clouds with multiple scattering.

I've had fairly good luck with the old 'cloud light' tool. It's no one click multiscatter like 3delight but it's workable.