Underwater Caustics Tweet

[mac]

Hey all?

How would you create decent looking underwater caustics? Is there a way to use Gobos or similar maps to affect light intensity; that would be my first guess to create the effect, but I can't seem to get it work.

Thanks,

[abreukers]

hi,
I have moved your question to the 'Resources and Sharing' forum as you might get more tips from there... cheers

[radiance]

Currently sunlight does not cast caustics in this way.
You need to use an HDR and place a sphere or disc (low poly) at a large distance so simulate a sun with an area light, then render with PMC.
You just need to displace the water geometry for wind/motion first, then export to octane and render.

[telemmaite]

I am also trying to get any underwater caustics using emitter + hdri. No success . Can you show me at least some that had achieved the result with octane?

[cornel]

dude, you´re crazy. I highly suggest to use a different approach:

Render your scene in octane without caustics.

Now generate a caustic texture in the desired resolution. Still frame or as a loopable animation.
Use this tool to accomplish the task easily:
http://www.dualheights.se/caustics/
it´s also available in a "free" version.

Back in your 3D core app:
Apply this caustic texture to your geometry using projection mapping (from above).
Render the scene conventionally as separate pass/layer and screen/lighten/add this in post over the image you got from octane.

done.


edit:
oh, I see that the free version of the caustic generator supports only a resolution of 512x512.
So better use some texture-tiling or get in touch with the pro-version.

I did a quick 10-minute example: check out the attachment.