Page 1 of 2

Volumen Causic

Posted: Fri Apr 13, 2007 12:33 am
by Sebastian
After some tests I give up hope....
Does anyone knows how to render a Volume Caustic with indigo.
Here are my settings and my (bad) result.

Posted: Fri Apr 13, 2007 12:41 am
by Kram1032
first: you should use specular if this shall be a perfect mirrior ;)

2nd:The ball in the middle is the SSSball?
You should make it as big as possible, I guess...
It should be a .sphere and the cam should be inside the sphere.

PLEASE add a screen of your balls settings :)
the SSSmat is important.

It doesn't look bad, btw.
I don't really think, that anything is wrong, but you need more time ;)

Posted: Fri Apr 13, 2007 12:55 am
by Sebastian
Here is another screen shot.
The Ball is Spec Material and Iro 1.5 (Glass) transp activated.
The Plane should be a mirror (with Phong settings).

Posted: Fri Apr 13, 2007 12:56 am
by OnoSendai
What kind of caustics are you trying to achieve?

Posted: Fri Apr 13, 2007 1:10 am
by Sebastian
Caustics like that:

http://www2.indigorenderer.com/joomla/i ... emId=10409

now it looks much better. But I've still no caustic "behind" the Glass Sphere :-(

Posted: Fri Apr 13, 2007 1:31 am
by Kram1032
I guess, you may should give the whole thing in a room, where all the rays can be reflected -> faster clear up.
Your's is somewhere in the void :P

Posted: Fri Apr 13, 2007 1:40 am
by CTZn
I think the top light is far too weak in order to produce caustics, ans the glass ball might have a quasi null absorbtion: more absorbtion, less caustics. Ior is enough to make it visible.

Posted: Fri Apr 13, 2007 1:55 am
by Sebastian
now i render the whole thing inside a box.

On the Image there are also the rendersettings. Has anyone an Idea how to render more effectient.

Posted: Fri Apr 13, 2007 5:07 am
by Sebastian
I almost got it !!!

I've one last Problem: The LightRays ignore the Prisma Object.
There is no refraction (or reflection) or any of this Rainbow-Effects !?

Posted: Fri Apr 13, 2007 5:16 am
by Kram1032
What's the IOR of the prisma?
IOR 1 means no refraction, nor reflection...
Dunno, what a prisma is supposed to have, as IoR...
But I GUESS, the higher the IoR, the less light goes through it, but the wider the angle of cbc is...

Posted: Fri Apr 13, 2007 5:17 am
by OnoSendai
Cool scene.. just give the prism an IOR like 1.7, and give it some cauchy b coefficient (dispersion) !

Posted: Fri Apr 13, 2007 5:18 am
by Sebastian
IOR is 2.75 so it HAS to deflect the Rays !

Posted: Fri Apr 13, 2007 9:06 am
by manitwo
Kram1032 wrote:... where all the rays can be reflected -> faster clear up.
sorry ... no :wink:

Posted: Fri Apr 13, 2007 9:15 am
by Kram1032
It shouldn't clear up fast, if EVERYTHING's reflected (white) but if a part is reflected, it should be ok.

In the void, many rays may just hit once nd don't get away much noise....

In a pure white room, as opposit, all the rays will be reflected as many times as you set them... THEN it also will need longer, as the computer let the ray bounce as many times as needed to get the limit. If you wouldn't define a limit (which can't be done anyway), you'd get an infinte loop and the first ray would fly though the scene for ever, without letting the computer start with the next one...
In that case, it should even need longer to clear up.

Posted: Fri Apr 13, 2007 2:03 pm
by CTZn
Sebastian wrote:IOR is 2.75 so it HAS to deflect the Rays !
Are you sure the ray is passing through the prism, and not behind ? I guess everything is strictly parallel in your scene, but as the result is not what was expected...

That's odd, could you post the material settings for the prism (xml/igs wise) please ? There must be something wrong !