[deppest]

Hi

First post as I can't get my head around this. While working on an outdoor pool scene I successfully managed to get caustics on the pool ground. The water was done with a cube and a water material with displacement. When I place the camera "underwater" beautiful caustics show up. However, when I move the camera above the water and pointing down these caustics can't be seen. This is with Maxwell V3 and Cinema 4D R15.

I have simplified the scene using a metal tube on a surface, sun environment and a lightly tinted glass panel above the scene which covers about half of the view. As you can see the caustics only show up where they can be seen directly, i.e. not through the glass. I've tried different thicknesses of the glass, different Nd values (including 1) to no avail.

If this a known limitation of Maxwell? Any workarounds? Any feedback appreciated!

https://www.flickr.com/photos/125622813 ... 464568865/

[numerobis]

If this a known limitation of Maxwell?

yes

Any workarounds?

No.

Not if you need refraction and absorption to simulate real looking water. Maxwell can not render real pool water.

You can try different sun diameters and see if it helps http://www.maxwellrender.com/forum/view ... 35&t=41876

Or you can only use AGS and fake the caustics using an alpha map in the water plane - but then without rafraction/absorption.

[Fernando Tella]

Well, technically they work, but take too long to show (around SL 32 you can get a clean render with normal sun radius). With wider sun radius they show faster. It's a physics problem; it's very hard for rays coming from camera to refract twice and find a very tiny and very far dot in the sky (the sun).

For a more practical solution, I usually use two planes for water. One with real water hidden to GI, which shows the bottom of the pool refracted, good looks and super clear but without caustics, then a bit above it I put another plane with AGS water hidden to camera and reflections/refractions with a mask to fake caustics and obscure the water a bit.

[Bubbaloo]

Maxwell can not render real pool water.

[numerobis]

oh, please... not again.

i've been waiting for this nice image

[Bubbaloo]

LOL I always keep it close when these absolute statements are made.

[numerobis]

[Fernando Tella]

Lol, I was thinking of that image when writing. It was SL 32, right?

[Bubbaloo]

It only made it to 32 or 33. I had to cut it short.

[Thomas An.]

A couple more years by Moore's law and we can do these in real time.

[deppest]

thanks for the feedback and I like the SL 33 picture! Would probably have to wait until my retirement if I were to try anything like this my self