Visible light without fog. How?

[R_Flash]

Hi. There is any ways to add a volumetric light on chosen lights without the addition of global fog to all project?
I need to add a volume light effect from old well on clean scene. I know this is not physical correct, but I need... Thanks.

[bepeg4d]

Hi R_Flash,
then you can go with the old way by adding a geometry to the light with the desired shape (cone, pyramid, ecc) with a specular material with IOR 1 and scattering medium node.
Be aware that the camera cannot travel inside the geometry, otherwise the effect become invisible
ciao beppe

[R_Flash]

Yes I know about this method, but his not usable for animated scenes with close-up shooting.

[bepeg4d]

Hi R_Flash,
not properly, when the camera hits the geometry, just surround it with an inverted sphere with the same fog material asdigned, and the volume effect will be still visible
ciao beppe

[R_Flash]

This method have many limitations for me. Why is it implemented much easier in Redshift. There is a global parameter "Volumetric Scattering" (analog of Octane fog) and in each light object is a parameter "Volume contribution scale", which control volume scattering influence. I hope Octane developers implement something similar in our beloved Octane in the near future.

[coilbook]

Octane always had confusing volume light. I wish we had it like in redshift or volume light per light. Just click turn on volume light button and adjust strength.

[bepeg4d]

Come on guys, comparing OctaneRender with Redshift, is like comparing a Ferrari (unbiased) with a Range Rover (biased)
They are both good expensive cars, but with a complete different philosophy and driving experience... you simply cannot expect the same behavior from the two
ciao beppe

[milanm]

Come on guys, comparing OctaneRender with Redshift, is like comparing a Ferrari (unbiased) with a Range Rover (biased)
They are both good expensive cars, but with a complete different philosophy and driving experience... you simply cannot expect the same behavior from the two
ciao beppe

Actually it's not even Range Rover, more like Lada Niva because it only works on Autodesk apps on Windows and Linux

Regards
Milan

[coilbook]

Come on guys, comparing OctaneRender with Redshift, is like comparing a Ferrari (unbiased) with a Range Rover (biased)
They are both good expensive cars, but with a complete different philosophy and driving experience... you simply cannot expect the same behavior from the two
ciao beppe

Actually it's not even Range Rover, more like Lada Niva because it only works on Autodesk apps on Windows and Linux

Regards
Milan

Niva is way better than range

[milanm]

Come on guys, comparing OctaneRender with Redshift, is like comparing a Ferrari (unbiased) with a Range Rover (biased)
They are both good expensive cars, but with a complete different philosophy and driving experience... you simply cannot expect the same behavior from the two
ciao beppe

Actually it's not even Range Rover, more like Lada Niva because it only works on Autodesk apps on Windows and Linux

Regards
Milan

Niva is way better than range

Exactly! But it's "user interface" is kind of.. stuck in the past. See my point?

Anyway, back to the topic.

I had a lot of problems getting actual (distance) fog from daylight medium which makes me think it would be a good way to go for volume lights if you wanted to avoid that fog effect. Whatever light is left in the blacks could be color corrected. If you needed more or less precision in diferent parts of your scene, you could use one or many volume objects. Volume object is actually the most efficient way to add volumetric effects to your scene. Use it like a bounding box arround lights. Turn of voxel preview. Use it with high step and voxel settings. Play with phase. GI Clamp helps. Caustic blur to zero helps. Coh. ratio helps. Pathtracing and PMC can be much faster than DL (believe it or not). Just don't rotate it.. for now

Regards
Milan