Corona Renderer Forum

Corona Renderer for Cinema 4D => [C4D] Feature Requests => [C4D] Resolved Feature Requests => Topic started by: Cinemike on 2018-02-08, 19:22:42

Title: Volume Lights
Post by: Cinemike on 2018-02-08, 19:22:42
I know they are easily set up, but I'd really like a checkbox in the light objects to simply add Volumetric Lights / Shadows to a Corona light.
Yes, Corona is a physically based renderer, but since the renderer with Mister Schwarzenegger's first name can do them and also claims to be physically correct, we should get them, too!
Title: Re: Volume Lights
Post by: TomG on 2018-02-08, 19:35:10
That might be a big request, as it isn't in the core :) Not sure how other engines do it, perhaps they create geometry tied to the light with a volume material on it? Not being great with Expresso, would it be possible to create a library object of some kind that was just that, a light with a cone attached where adjusting the directionality / spotlight parameters would adjust the geometry too so that it was always large enough to catch the volumes?

Of course, then it would still catch the volumes of other lights passing through that geometry too, since volumetrics are a property of the medium the light goes through, not of the light itself :) An include / exclude list might work for that though, to keep the geometry only affected by one light... but then adding it to the scene would need all the lights updated to exclude that particular geometry, so even that would be complex to set up automatically.
Title: Re: Volume Lights
Post by: Cinemike on 2018-02-08, 20:25:42
I have no idea how it is done in other engines, but that's the beauty of being a user: We wish for features and don't give a cookie about how it is done - we just let the coders sweat ;)

Using Xpresso should work for a workaround, though, but the "real deal" would be nice to have.
I don't expect it to be in within a week or two, of course, but how about March? ^^

Well, seriously, it would be nice if you could consider adding this at a later point of the development.

Title: Re: Volume Lights
Post by: TomG on 2018-02-08, 20:34:15
All requests are always considered :) Just wanted to note that this likely is a request that would have to go to the core team, rather than the C4D team, as I suspect it would be a core thing. If so, then any support of the request would have to fit in with the core development plans, and not just the C4D development plans, and that most likely means that if this is possible, and does get chosen to be implemented, it would be a longer wait than other requests that are just in C4D!

Title: Re: Volume Lights
Post by: Eddoron on 2018-02-09, 10:31:11
Volume lights is a feature that is very uncommon in unbiased renderers. They basically just imitate the reaction of light on a volume.
What you could do is to create a light and append a box with a volume material and have only that in the include list.
That way you'd only get the volume of that single light. Then copy the light and exclude the material/box from that for illuminating the rest.
Save it under one object tree and you can use it as a preset.
Good if you only want this for a special effect, but it could get more complicated as soon as other lights are involved.(as Tom said)

What I'd do, if I only wanted the c4d like volume in a crn scene, would be to render the (c4d) volume light separately and add it later in post.
A lot of things from different engines are mixed in postproduction. You can render a table in engine A and mix it with the environment of B if B creates better shadows. etc.
Title: Re: Volume Lights
Post by: PROH on 2018-02-09, 16:56:24
Hi. I know that this is a C4D request, but as Tom says, it's most likely a core feature. So as a 3dsMax user I would benefit from this too :) :)

Therefore I say +1000 for Cinemikes request!

PS - I know there's several ways to work around this. But why not be the first render engine that makes this simple for the user?
Title: Re: Volume Lights
Post by: TomH on 2019-03-11, 00:32:56
Would STILL be great (well crucial actually) to have volumetric lighting controllable on a per light basis, like C4d & Redshift does.

Title: Re: Volume Lights
Post by: robpayne on 2019-03-15, 17:41:01
For the record, Arnold lights don’t scatter without a volume to react with. They do however have a slider that can reduce the scattering on a per light basis, which makes it easier to art direct, albeit in a non-physical way.