Chaos Corona Forum

General Category => Gallery => Topic started by: tuffmutt1 on 2013-07-01, 23:00:56

Title: Corona scatter test
Post by: tuffmutt1 on 2013-07-01, 23:00:56
Two Images of the same thing. Click on the image for full res. HD.
one is 3:37 minutes
 (http://s22.postimg.org/r9a880oyp/Front_Fish_Tank.jpg) (http://postimg.org/image/9vzxt5tnh/full/)
screenshot capture (http://postimage.org/app.php) and the other is 6:15.
(http://s17.postimg.org/i9n4xssj3/Front_Fish_Tank001.jpg) (http://postimg.org/image/55hkl40h7/full/)
windows screenshot (http://postimage.org/app.php)
How do i get caustics?
Title: Re: Corona scatter test
Post by: tuffmutt1 on 2013-07-01, 23:22:27
Some contrast and vignetting added in Photoshop.
(http://s8.postimg.org/ddz7s46z9/Front_Fish_Tank_Colorcorrected.jpg) (http://postimg.org/image/pslzsfyhd/full/)
image upload (http://postimage.org/)
Title: Re: Corona scatter test
Post by: maru on 2013-07-02, 11:55:02
Damn, this is really nice! But something wrong is going on where water meets glass. Looks like it DOESN'T. It looks like a floating cube of water in a much bigger glass container.
Title: Re: Corona scatter test
Post by: abdsf on 2013-07-03, 01:46:28
change render to VCM
Title: Re: Corona scatter test
Post by: stevenchman on 2013-07-03, 16:17:32
change render to VCM

What is the benefit of using VCM? 
Title: Re: Corona scatter test
Post by: Archangel on 2013-07-05, 13:19:18
Noting to do with render!.

Simple your water mesh must go inside glass mesh litlbit. And problem resolwed.
Title: Re: Corona scatter test
Post by: maru on 2013-07-05, 19:37:05
Noting to do with render!.

Simple your water mesh must go inside glass mesh litlbit. And problem resolwed.
It's not true! You should never do this. At least not in Corona.

Read this:
http://forum.corona-renderer.com/index.php/topic,292.msg2025.html#msg2025

Here is most physically correct method:
You detach the inside part of your container geometry, cap it to the water level and set it's IOR value to 1,33 (or whatever liquid you want inside).
http://forum.corona-renderer.com/index.php?action=dlattach;topic=292.0;attach=1215;image
Title: Re: Corona scatter test
Post by: tuffmutt1 on 2013-07-05, 20:40:59
Thanks for the comments guys.
About IOR for water/air /Glass...the Mental ray archDesign material help file has a solution for this/ but in corona
we cant go IOR below 1.0.
From the help file:


The solution is to rethink the modeling, and not to think in terms of media, but in terms of interfaces. In our example, we have three different interfaces, where we can consider the IOR as the ratio between the IORs of the outside and inside media:

    Air-glass interface (IOR=1.5/1.0=1.5)
    Air-liquid interface (IOR=1.33/1.0=1.33)
    Glass-liquid interface (IOR=1.33/1.5=0.8)



Title: Re: Corona scatter test
Post by: maru on 2013-07-05, 20:54:13
Just read the thread I posted. I also showed your method to Keymaster but he said it's wrong. In Corona you should not divide IORs.
Title: Re: Corona scatter test
Post by: tuffmutt1 on 2013-07-06, 10:35:34
Thanks maru. read that thread.
but how would one go about doing it if it was an animated water using something like realflow or Frost?
as the mesh topology changes with every frame it seems it would be difficult to model IOR surfaces for each frame.
just wondering.
Title: Re: Corona scatter test
Post by: maru on 2013-07-06, 16:47:54
Good question. Never thought about it.
Title: Re: Corona scatter test
Post by: Archangel on 2013-07-09, 00:13:41
:) Maru. My metod is almost the same thing what u describe for solution, buit litlbit diferent and easyer.

In my metod i do litl trick. Maby is not phisicaly corect but jet, maby it is. Look at this my work in corona , i just did what i described as a solution abowe, not only for corona renderer, but for many renderers.

So look at glass and thell me do u see somthing wrong or not?.
Title: Re: Corona scatter test
Post by: maru on 2013-07-09, 18:36:44
It looks fine but maybe Keymaster would shout at you. ;)
Title: Re: Corona scatter test
Post by: Ondra on 2013-07-09, 19:27:45
I've changed the way it works, now the "overlap" method should render correctly for most "water in glass" situations
Title: Re: Corona scatter test
Post by: maru on 2013-07-09, 20:09:45
Shit.
Title: Re: Corona scatter test
Post by: Archangel on 2013-07-10, 18:38:37
Dont worry maru. Ultimate goal for Keymaster is to make his renderer one of the best in the world(almost done :D), so my dear maru. Any sugestion as crazy as it sounds, stil can be usefoll ;) .
Title: Re: Corona scatter test
Post by: borislemke on 2013-07-11, 02:56:33
Should we use the same method mentioned(overlapping thing) in animated scenarios as well? Will try this when I get home(currently in vacation :D )
Title: Re: Corona scatter test
Post by: Archangel on 2013-07-12, 13:13:09
All great things, coming from experiments!. ;) . Yes you need to tray make animations with that method and see how it will work. From my experience it will work very good.