Author Topic: Volumetric FOG  (Read 13750 times)

2016-02-28, 08:03:31

hadid90

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Hello,

Corona volumetric fog sucks .. Here i said it :P sorry .. it really sucks .. I watched the corona tutorials, read a lot of threads still dont get any near the results im looking forward to .. i have a large exterior scene .. and it was so simple and easy in vray, but so hard and awful in corona..

I hope it does get updated in the upcoming version...

Thank you
Hadi

2016-02-28, 09:31:18
Reply #1

romullus

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Care to show what you're aiming for? Your mentioned Vray example would be perfect.
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2016-02-28, 10:02:32
Reply #2

hadid90

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Check the result in this video


2016-02-28, 10:31:14
Reply #3

FrostKiwi

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Check the result in this video

Ohh dear.
You missed the point of both the Video and corona fog.
The Video clearly demonstrates direct light only fog by overriding global materials with a 0RGB material to eliminate GI. You can do this in corona as well.
On a basic level vray fog and corona fog do the same thing - scatter light rays. The tutorial shows you how you can force it to stop scattering all light but only from one light source.

Then it's composited on top in Photoshop.
This can be done in corona the same way.

What corona fog tutorials aim at is putting fog physically in there with at least amount of user input.
The vray workflow in this video shows the opposite. Fast direct light fog with a trick to Photoshop.

With Corona's aim at simplicity and physical correctness above all things like this rarely are mentioned or worked with in Corona world. Corona wants the artist to get a bit further from post prccessing reliance on stuff that the engine should do in itself. But still both fogs do the exact same thing and you can do the same result if you force single bounce only and override for 0 GI rays.
« Last Edit: 2016-02-28, 10:34:38 by SairesArt »

2016-02-28, 10:51:37
Reply #4

hadid90

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Hello my friend,

Getting this kind of fog in Corona is really hard.. Also it only happens in some particular situations. On the other hand, fog in vray is easy and not complicated at all .. I m not concerned about the realistic look of it .. i want a more exaggerated effect like the one in the vray video i posted above .. I tried for hours and hours and more than once and more than 1 scene to replicate this effect but i couldnt at all .. not even near it ..

Hope u understand me my friend .. and maybe u can point out to a tutor that shows how to get this same effect with vray ..

Thank you
Hadi

2016-02-28, 11:14:19
Reply #5

FrostKiwi

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Post scene file if possible, I can't believe this to be harder then clicking single bounce, putting color to white and making everything else black. Provided light and geo is setup correctly aswell, there is no reason why it shouldn't deliver the same result. No need to adjust back or forwards scattering, we can ignore that if we do direct only.
Also, fog pass from one of the scenes I currently have open.

2016-02-28, 11:21:40
Reply #6

hadid90

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Hello,

I believe i clearly mentionned in my initial post that i have an exterior scene.. Also the vray video shows an exterior scene, while your scene is an interior one .. Also, to achieve your result u needed to have a really dark scene and high contrast, while on the vray scene it s not that dark, and about no contrast at all ..

I did what u mentionned about the single bounce only .. and i ve done everything correctly i believe .. i have 1 sun .. the sun is somehow in front of my camera to acheive a strong effect (while in vray it doesnt need to be in front of the camera) .. i did everything like they did in the tutors .. but i dont like the effect they are getting in the tutorial .. i certainly dont like the effect im getting too ..

I started this thread in the hope that maybe in the future releases the volumetric fog thingy might get better ..

thank you
hadi

2016-02-28, 12:12:22
Reply #7

Ludvik Koutny

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Only real difference between corona fog and V-Ray environment fog is that V-Ray fog can do heterogenous media (you can map color and density of fog in real 3D volume) and that you can choose exact number of indirect bounces, where as with corona, it's either direct light only, or full 25 indirect bounces.

None of these two differences prevent you from achieving exactly same exterior fog as with V-Ray. If you can't, then well, you are doing something wrong :)

2016-02-28, 15:36:03
Reply #8

hadid90

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I am getting results same as MR. SairesARt .. im not doing anything wrong .. i m just saying that vray results are much better :P much like how i need the fog to be .. In corona i m having hard times getting the result i want :P

2016-02-28, 15:47:22
Reply #9

romullus

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Maybe it's just a case of adapting your workflow, as it was already suggested. I don't think Corona's volume will be reworked just because you think it's useless.
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2016-02-28, 16:00:19
Reply #10

hadid90

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I dont think IT s useless at all ..

ALSO I WAS DOING SOMETHING REALLY WRONG ! Putting the absorption color to full 255 white disables the fog totally ! :P

HAHA SORRY GUYS

2020-01-10, 20:01:33
Reply #11

nockain

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I think the same, so we are two people with the same problem. I do not understand why it is so rare in corona, and in vray it is so simple and understandable to understand.

It is really so difficult to adapt the corona way to a simpler form, maintaining what we already have.

Believe me, it is really difficult to obtain the desired effect easily, underwater fog, with various levels and colors. Without commenting that Vray has an aerial perspective that already leaves a post about it, things that corona does not do well either, and I don't understand why Corona does not take the whole matter of the fog, fog volume, air perpective, and simplifies it.

I do not understand why it is so bulky. I know a lot of people who don't use it for this reason.