vRay Environmental Fog - fallof problem

V-Ray V-Ray for 3ds Max General
1

Hi,
I have problem with vRay Fog: How to apply falloff for sphere gizmo (density on the edge)?

earthfog.jpg
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2

You can use a Falloff map in distance blend mode from the gizmo.

Best regards,
Vlado

3

Thanks Vlad! Working good!

4

I’ve tried to replicate this but I don’t know where to find that “distance blend” Vlado refers there. Is it the density texture slot?

Thanks

5

Vlado means put a falloff map - set to distance blend - in the density slot of the fog.

6

I have two follow on questions :

1.When apply the distant blend what mapping type should you use say for a sphere ?
2.If you are creating lets say a cloud and are using the distance map to control the density how do you do also create a rough edged cloud shape

If anybody has some nice cloud examples with settings they’d care to share, I’d love to see them

Thanks as always

Adam

7

There are some examples in the help index, but I suppose you have already seen those:

Best regards,
Vlado

8

ooh, I wish these scenes were max9! :mrgreen:

9

Thanks for the reminder, I saw these examples while back but completely forgot about them, tehre also seems to be better examples now, I’ll spend a bit of time and got through these to get a handle on what I’m doing - I so often go off half cocked with my experimentation, I suppose the best thing to do is to recreate them and go through one by one - of course if they where already created for me somewhere in max 9 … nah that would be too easy

I’ll get my receptionist to hold all my calls - I’ve a fun afternoon ahead of me :]

10

not to sure if this is the best place for general environmental fog questions but can two fogs interact. for instance, if i do some clouds with the fog. then use another fog just for haze. would i get to see the “god rays” or whatever other people call them (the volumetric light) shinning through the breaks in the clouds?

11

Currently two atmospherics will not blend properly; we will be working on this for the next builds. It may be possible to achieve this with suitable textures, but it would be quite tricky.

Best regards,
Vlado

12

i guess some form of a gradient to seperate the lower level fog from the upper level clouds might work

13

Back to the “Rough edges” question, is there a way to get this, Afterburn style?
All the test I have done (not many!!) have awsome volumetric noise, but then cut out of a sphere (or box). I have used the falloff, but it just faeds out that effect. You almost need a falloff that does it with noise rather than a uniform fade. See below. Top one Vray, bottom AB.

fogTestVray.jpg
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fogTestAB.jpg
fogTestAB.jpg640×480 7.33 KB

14

You can use a Falloff map in distance blend mode from the gizmo center to control the edge softness. You can combine this with the noise in a number of ways to get different effects.

Best regards,
Vlado

15

I have tried that vlado, but cant seem to get the right look :frowning: It just fades off the noise so you get a blurry look.

16

Well it depends on what you do with it; you can for example do stuff like this. It was done by adding a falloff to the noise and clamping the result so that it is not negative.

Best regards,
Vlado

puff.png
puff.png400×400 49.8 KB

17

That looks great Vlado! Could you post the scene for that? Im still having trouble getting that look. Using a Falloff with a noise in the white channel of the falloff and checking clamp in the falloff

edit: Oh, i see now, you used the output curve to clamp the falloff! Cheers!