[Wynott]

This is probably a bad word here... But I'm working on a tropical environment to put boats in. I'd like to show some somewhat exaggerated caustics on the seabed. Think bora bora postcard.

My first try was basically adding a map to the sandy bottom...

As we're in shallow tropical water, my boat is casting a shadow on the bottom and the sea bed material doesn't look so great in the shadow, as the caustics should go away and if anything they get pronounced by the shadow on the white sand.

Lots of other problems here but I'd like to tackle this caustics thing first. Obviously I haven't chosen such a great texture to use but does anyone have a suggestion for how to get this to look sortof alright?

[F. Tella]

Hi Wynott,

Please check this thread: http://www.maxwellrender.com/forum/view ... sun+radius

I posted there some tests changing the sun radius. A bit below I get a good render with sun radius= 10 (SL 24); the bigger the sun the smaller SL you need, but you get softer shadows and caustics.
If you don't want to render the boat up to SL24 or don't want the softer shadows cast by a radius 10 sun, you can make two different renders; one for the water and the other for the boat. Notice that you can also use extra sampling to speed up the render.

Best,
Fernando

[Wynott]

Thanks Fernando

I guess my problem here is that I'm using an HDR. Maybe I would get a similar result if I artificially made the sun larger in Photoshop. Will try and report back.

[seghier]

Thanks Fernando

I guess my problem here is that I'm using an HDR. Maybe I would get a similar result if I artificially made the sun larger in Photoshop. Will try and report back.

are you tried with active sky under : IBL settings --> illumination

[Wynott]

Hrmm this is sun dia 25 and SL 24. Not really getting anything except some little black spec defects. they aren't part of the sand bitmap. the little black defects look sortof like they're trying to be caustics.

Ignore half done boat please. Water is looking awful now also. I turned Nd down to 1.2 as to see into the water better but maybe this is the problem? Or perhaps I need more detail in the surface material like some finer bump ripples than maxwell sea can do?

I'll try sun 10 now.