I always fail big time trying to do caustics. I don’t suppose anyone has a basic scene set up in centimeters for how to do caustics for a standard pool for arch viz use??
I’ll be lighting it with a HDRi but i dont care if it uses that trick that Bertrand linked to (http://bertrand-benoit.com/blog/2011/09/08/free-caustics-anyone/)
pretty please!
a free HDRi sky for the first ones to help! 
Usually all you have to do is to enable caustics and hit multiplier to 99999 untill u see caustics and then slowly lower it down untill its what you like. Also use point lights - as it is the fastest caustic generator - IBL might be a bit heavy on caustics…
tried that.. not working for me
well, I successfully confirmed that I am an idiot at the very least.. I had affect shadows turned on so wasnt getting refractive caustics!
NOT having a good day!
Umh in vray output window, does it say generating caustics? Also make sure in caustics settings the search distance and max density(or something named similarly) have value bigger than 0.
out of interest in case anyone knows, how do the scene units affect caustics? (search distance etc)
not sure if you have seen this already? but its an absolutely life saver when it comes to caustics https://www.youtube.com/watch?v=F2c8cSArXnM
dont forget to do a foggy caustic pass under the water, ha.
that looks great dude, nice one! is that foam phoenix?
Can you send me the scene for this? Unfortunately caustics tend to be related to the scene size etc, so it’s difficult to give a general advice.
Best regards,
Vlado
sent you an email Vlado. If you have any time to look at it, feel free to post findings here.
Looks great, Peter. And thanks for sharing that tutorial - what a clever work-around!
I’ve been struggling to get some nice crisp realistic looking caustics for an outdoor swimming pool and as far as my research on the subject goes, it’s pretty much dependent on the depth of the pool and the geometry of the surface of the water. and if you really want something good for high res images you really need to work on that geometry.
One of the most important thing is also the surface itself. Just some noise pattern doesn´t work to well. Here are some pool test I did some years ago with Reaktor Water (RIP sweet prince). It was the best solution for realistic water surfaces.
http://sorceress.netfrag.org/optix/s\_caustics\_01.mov
http://sorceress.netfrag.org/optix/s\_reactorwater\_01.mov
When working with caustics from Lights, I ´d suggest using standard direct lights. For me those are the most predictable. No need to turn the multiplier up by factor 10000
(It´s only spot light that need to turned up by that factor as far as i remember). Also keep the radius of the light as small as possible. It´s not a good idea to take for example a sun that illuminates a whole scene as caustic emitter for a glas standing on a table. Make an extra light only for caustics that just covers the necessary area.
that looks great! How can I make a similar pool surface these days? MassFX?
Someone told me about a plugin a while ago. I don´t really recall it. It was commercial. I thought it was called something like splashmax.
But I can´t find anything on google.Probabely the name was different. I also remember it was a pretty old plugin but available for newer version.
Maybe someone else remeber that particular plugin ?
http://splashmax.scglabs.com/home.shtml is this it?
I think that´s it. With the exact name I found this.
Seems to be newer but also somehow outdated. No price and it´s nowhere on the Digimation Website. 
But I ´sure someone pointed me to a version for max 2012 oder 2013.
The ocean displacement texture that comes with the phoenixFD demo is incredible. You might be able to use it for pool water if you dial it down enough.
Not pool water but Tommi from work created this for the evermotion challenge using this Ocean texture. The only 'shopped thing about the water are the large splashes near the water’s edge and the grading tweaks…
Surely this would create awesome geometry for caustics…
