Volume Caustics?

[Artiztick]

I know what u mean, i tried playing with it and i had no luck, i couldnt notice anything!

http://www.metafex.net/cinefex/tutorials/index.php

I know there is a tutorial on that site! I havnt tried it yet, it looks pretty basic and easy to follow - try that

EDIT*
Whooops, its in your sig so you seem to know about it already!
Sorry i dont know any other sites :surprised

[Kotayus]

yes, lol...cinefex is my site! that was funny...i am always plugging it and i thought it was a joke...

Well i read in the manual, you have to have a volumetric light in the scene...that is just crazy! volumetric with caustics? erm...maybe to much? If anyone has some very SIMPLE volumeric caustic settings i would LOVE to see em.

[LucentDreams]

added a sutble bumb (really large 3D noise in the bump channel) to a transparent material on any object your casting caustics on, then boost the energy to 400% you should definitely see a nice result. I have an awesome new render, but have to get some permision to show it first. trust me they are worth it.

[Kirl]

Indeed, thinking about it I don't remeber ever seeing volume caustics in real life...

While I regularly take a hot (=misty) shower while a bright sun is peeking in, shining on curved reflective surfaces. :shrug:

[LucentDreams]

renders are fast if your wise, 2 minutes too long? how about 4? on average a 1024x768 for me takes about 30 minutes, but thats using AA 2x2 8x8 and some intensive shaders. have you guys looked at the spectral caustic example for R8?

[Kotayus]

i dont think ive seen the caustic example for R8...and true volume caustics dont seem ALL that real...but then again i make abstracts so...blah! It just iritates me cause i couldnt figure it out...and im trying it with volumetric lights and still...nothing.

[tcastudios]

Just had to try myself. First nothing till... I put a fraction of reflection on the materials. Bang. I´m happy I just put 1.5 Gb in my computor. Default settings (plus the 400% suggested here) hits 500 meg in proton casting.
Lennart

[LucentDreams]

man I'm on crack too, yes you do need volumetrics, usually it helps to boost energy, 100% for volume is usually too subtle. alo to reduce render times, use lwer amounts of photons in a spot light rather than using omin lights, thats poeoples most common mistake is using an omni light.

Think of it this way, an omni light is basically 6 spot lights, so your casting 10 000 photons in six directions. thats only 1700 photons in anyone direction in reality, most of those photons are going to miss their target too. However using a spotlight now all 10 000 photons are doing in one direction, you chances of more phtons hitting the target are greatly increased.

[TimC]

Originally posted by Kaiskai
Think of it this way, an omni light is basically 6 spot lights, so your casting 10 000 photons in six directions. thats only 1700 photons in anyone direction in reality, most of those photons are going to miss their target too. However using a spotlight now all 10 000 photons are doing in one direction, you chances of more phtons hitting the target are greatly increased.

Choose Link to active object and then focus the spotlght exactly, wasting minimum photons.

TimC

[LucentDreams]

Originally posted by TimC
Choose Link to active object and then focus the spotlght exactly, wasting minimum photons.

TimC

Or use a target expression, though yours can be even more accurate if the objectts acis is not center well.

[AdamT]

I guess it works.

http://bellsouthpwp.net/A/d/AdamTrachtenberg/cstcs_vol.jpg

[Kirl]

Looks a bit like the effect in Ants (or a Bug's life, not sure) where the little ones are getting scorched by a magnifying glass...

What was the render time?

[LucentDreams]

The movie was Antz. And actually though I don't know how they did the effect in antz, this is an example of the actual phenomena. Basically all the light is bent into one concentrated beam. Same idea as how lasers work.

[AdamT]

Render time was 35 minutes on a dual 2.4Ghz Xeon. I should've used 50,000 samples instead of 100,000. That would've made it much shorter.

[Kotayus]

lol, i hit F5 and rendered the perspective view...and it took 35 minutes...and there was no volume caustics...it seems like a nice effect but to render intensive...perhaps with enough messing around there can be a easier way? or a shortcut...i might try working on it. Thanks adam, it was nice to see someone actually get it!

[TerryGH]

It's an interesting effect, though not something one uses for, or encounters a lot in, real world imagery.

A year or so ago I fiddled a bit with it, trying to create a focused dual lens effect with vol caustics and came up with this:

http://users.ntplx.net/~thallad/stuff/light6.jpg

Never tweaked it much to improve the effect, as I was just curious how refraction affected the volumetric caustics.

[AdamT]

Cool effect, Terry.

And I agree--it's not something you often see.

[Kotayus]

perhaps not...but in some situations it could be kinda cool...i would like to try to get some results. Adam or Terry, could you post some simple settings for me to get an idea?

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.