gradient fog

Corona Corona for 3ds Max Help Required
1

Hi All

Is it possible to create a fog that uses a gradient from 100% fog to 0% within an object ? I am using a standard corona material with 0 opacity and procedural maps in vol absorption which is great but there is still a defined edge where it hits the faces of the object. Any way around this ? It needs to be contained but I would like to use multiple objects for varying degrees of fog.

Cheers.

2

I found a work around using multi sub-object and translucncy map but if anyone has a better idea, or I am missing something then I would be happy to hear it.

3

most people use the zdepth pass to make fog. you could brush it a bit in PS to make it look irregular.

4

I am not sure what you are trying to achieve. Here is my example. Am I close? It still looks pretty ugly in some places though (pic2).

foggr.jpg
foggr.jpg1294×431 81.7 KB

pic2.jpg
pic2.jpg1438×424 88.4 KB

5

And here is a version with falloff to make softer edges.
And another one with scattering enabled, which seems to fix the issue from pic2.

falloff.jpg
falloff.jpg647×426 21.3 KB

sss.jpg
sss.jpg1300×432 80.7 KB

6

That’s fog Maru?

7

I’m not sure what exactly this thread is about but:

Is it possible to create a fog that uses a gradient from 100% fog to 0% within an object ?

8

Hi Maru

thanks for the images and trying to help
., yes that is sort of what I am trying to achieve, I just found that when placing fog within the confines of a box it starts showing the faces, sort of like pic 2. What are your settings for the second set of images with a fall-off map?

9

Hi. Just a little note that might be usefull.

AFAIK fog in Corona (at the moment) is not “within” the geometry, but is actually “on” the objects surface - like any other material. But when using absorption and scatter it can be made to look like it’s inside. Therefor it’s also depending on the shape of the used geometry. So if you want the fog to fade, it’s better to use round/rounded geometry instead of boxes (just like Marus example).

10

Thanks PROH

I think that is where It had me so confused and why I was trying all kinds of weird things to hide certain sides of the box i was using.

11

I should be able to send my scene today or tomorrow if it’s helpful.

12

here is the scene in max14
sss-opacity-14.max (248 KB)

13

Thanks Maru

That certainly helps.