Author Topic: Mie & Rayleigh atmospheric scattering  (Read 3324 times)

2017-02-27, 21:55:02

juancarlosgzrz

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Hey I've been testing volume rendering applied as atmosphere, I used a Corona Sun, black environment.  The edges of the atmosphere are hard because there's no option to control density with a map or even control de directionality (Anisotropy) As the atmosphere on the edges it's more visible than on the center.

I've attached a sample rendering.


« Last Edit: 2017-02-27, 23:25:03 by juancarlosgzrz »

2017-02-27, 22:55:49
Reply #1

agentdark45

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Nice, would be good to see the developments of this.
Vray who?

2017-02-28, 00:59:43
Reply #2

mferster

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Here is a super exaggerated atmosphere that i came up with.

Made with one sphere ( your planet)
Then a large sphere overlapping it (your atmosphere)

The atmosphere material I made is super simple.

0.05 light blue diffuse.

Opacity: 0.25 level; with the falloff map shown in the capture. You adjust the sharp point in the mix curve so it lines up with the horizon of your planet

2017-02-28, 01:34:14
Reply #3

juancarlosgzrz

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2017-02-28, 16:56:40
Reply #4

mferster

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Here is my scene file if it helps

2017-02-28, 17:15:26
Reply #5

maru

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Density (absorption) can be controlled with a map.
There is also directionality.
It should be easy to get soft edges by simply tweaking the absorption distance. Or maybe I do not understand something?

2017-02-28, 17:20:42
Reply #6

Ludvik Koutny

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Unfortunately, Corona can not deal with this yet, as it does not support heterogenous media. You should cast the vote in most requested features list thread.

Only way for now is to fake it using falloff map, as someone above already described, but it's still a pretty bad workflow as it requires matching the end of falloff curve super precisely based on the radius of planed relative to radius of atmosphere.

2017-02-28, 17:38:34
Reply #7

juancarlosgzrz

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mferster Thanks buddy I'll check it out.

maru  :  That parameter does change volume density but it's homogeneous meaning the same density at all points, so I need this value to go at sea level i.e. 1, then the higher the altitude the less the value, creating a gradient like effect.

2017-02-28, 17:42:23
Reply #8

maru

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maru  :  That parameter does change volume density but it's homogeneous meaning the same density at all points, so I need this value to go at sea level i.e. 1, then the higher the altitude the less the value, creating a gradient like effect.
Oh I get it now. Sorry, I probably read the thread too briefly.

2017-02-28, 20:54:40
Reply #9

Ondra

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Unfortunately, Corona can not deal with this yet, as it does not support heterogenous media. You should cast the vote in most requested features list thread.
Does needing this for one test project really makes it the most wanted feature? Remember, that thread is not "every feature needed ever", but "what hurts you the most generally"
Rendering is magic.
Private scene uploader | How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2017-02-28, 21:12:02
Reply #10

Ludvik Koutny

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Unfortunately, Corona can not deal with this yet, as it does not support heterogenous media. You should cast the vote in most requested features list thread.
Does needing this for one test project really makes it the most wanted feature? Remember, that thread is not "every feature needed ever", but "what hurts you the most generally"

No, but heterogenous volumetric media is needed by a lot of people for many different use cases, and if implemented, it would cover this use case as well.

Actually, rendering planets is not always a test use case. I remember helping a studio render planet atmosphere in Corona couple of years ago, because they could not find a way around it, and ended up suggesting to use the falloff map fake, which worked, but the workflow proved so tedious they reverted to V-Ray for that project. And I myself was doing some planet renders not that long ago, and had to resort to that ridiculous workaround too.

I think when people think of heterogenous media, planet atmosphere is one of the last things they consider, and despite that, it's now #1 request. That speaks for something, especially considering Corona has mainly archviz userbase now.

2017-02-28, 22:05:49
Reply #11

bluebox

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Unfortunately, Corona can not deal with this yet, as it does not support heterogenous media. You should cast the vote in most requested features list thread.
Does needing this for one test project really makes it the most wanted feature? Remember, that thread is not "every feature needed ever", but "what hurts you the most generally"

No, but heterogenous volumetric media is needed by a lot of people for many different use cases, and if implemented, it would cover this use case as well.

Actually, rendering planets is not always a test use case. I remember helping a studio render planet atmosphere in Corona couple of years ago, because they could not find a way around it, and ended up suggesting to use the falloff map fake, which worked, but the workflow proved so tedious they reverted to V-Ray for that project. And I myself was doing some planet renders not that long ago, and had to resort to that ridiculous workaround too.

I think when people think of heterogenous media, planet atmosphere is one of the last things they consider, and despite that, it's now #1 request. That speaks for something, especially considering Corona has mainly archviz userbase now.

Totaly agree, one can see this being requested for some time. Imho very important now, when archiviz is shifting and is not about making only sunny images anymore, but also making very very moody images. Fog is one of those moody additions that can change otherwise boring scenatio into super interesting one ;)



Don't get me wrong, I dont want to start "this over that" debate again because I can (to a certain degree) understand your point of view of providing most complex rendering package you can, but you guys really could think of supporting for example phoenix fd or any other similiar package instead of lets say  further development of Corona Scatter (I don't mean you should totaly forget about it) which in my humble opinion is basically reinventing the wheel since one can get Forest Pack or Multiscatter which both are far superior atm.
You already provided an intermediate scattering solution to people needing one, if they need something more powerfull they can get one of the above and will still remain your clients. Those requesting support for non homogeneous media still don't have anything :)
« Last Edit: 2017-02-28, 22:19:40 by bluebox »

2017-02-28, 23:54:40
Reply #12

juancarlosgzrz

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@Rawalanche @bluebox You are right

So @Ondra, I can do this in Vray, Cycles, but there's no way to do it in Corona? :1

2017-03-03, 00:14:36
Reply #13

juancarlosgzrz

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2017-03-30, 15:41:17
Reply #14

jorari71

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I have the same needing: how to implement this fading atmosphere for a planet rendering from the space.