Corona Renderer Forum

Corona Renderer for 3ds Max => [Max] Feature Requests => Topic started by: JoachimArt on 2021-08-14, 01:05:08

Title: Corona Volume Edge Feather
Post by: JoachimArt on 2021-08-14, 01:05:08
I have mentioned this before but I would like to add a new request for it, because I think it could be really useful and I miss the possibility so often.
The Corona Volume material is great, but very often when you want to use it for such things like ground fog or dust with a certain height or areas (not only full screen fog) the edges becomes to hard. and increasing the absorption distance only make the volume less opaque, but the fade to the edge of the volume stays the same. It would be very useful if you could control the feathering towards the boundaries.
See image example.
Title: Re: Corona Volume Edge Feather
Post by: TomG on 2021-08-15, 14:52:16
This can be done using the Corona Distance Shader, in various ways :)
Title: Re: Corona Volume Edge Feather
Post by: JoachimArt on 2021-08-16, 16:19:13
Thank you that is a good tip and something I will use. But it doesn't solve it completely though. The edge of the mesh still has the same size for the falloff (see attachment), its only possible to use the distance map to fade it additionally. Secondly, Distance map doesn't really work on Volumes unless you turn on Inside volume mode (which is insanely slow) and basically 4x rendering times. With my suggestion you could avoid that.
Title: Re: Corona Volume Edge Feather
Post by: maru on 2021-08-17, 17:40:15
Here are two ideas for volumetric feather effect - one with the falloff map and one with Corona Distance as Tom suggested.
In some cases the "inside volume" mode can render slowly, true. But maybe you can speed it up by using a higher "step size" value and enabling the "single bounce only" option.

Title: Re: Corona Volume Edge Feather
Post by: JoachimArt on 2021-08-25, 08:13:10
Thank you, I will use that. I personally still would wish for a volumetric material with a bit more options for stylized scenes where you need more control to finetune.
Title: Re: Corona Volume Edge Feather
Post by: maru on 2021-08-25, 17:35:28
I am sure there is room for improvement here.

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