Now I haven't read any of the documentation, including the new features list, but.....

Agents Smiths marbles picture seems to have caustics.    Can this be true, or does it just look like caustics and it's actually just refraction?

looks like them, but you know AS he may have faked 'em...

Quote - Now I haven't read any of the documentation, including the new features list, but.....

Agents Smiths marbles picture seems to have caustics.    Can this be true, or does it just look like caustics and it's actually just refraction?

how could it be refraction? what is 'just refraction'? the spherical distortion you see through the glass marbles, yes, that's refraction, but the brightening spot nearby under those same spheres, I don't think that's possible other than through some form of caustics, faked or precise, or through some post work (easy enough in a case like this to lighten up an elliptical shape).

You know, there are more polite ways of calling someone stupid.  There was no reason for your first two questions in order to get your point across.   The rest of your post covered the point more than adequately.

"Caustics - The enveloping surface formed by light rays reflecting or refracting from a curved surface, especially one with spherical aberration."

Maybe that is being caused by the HDRI?
Haven't had any time to use those yet. Look forward to experimenting with them, and B6 in general.

Attached Link: http://www.3d-digital-wasteland.com/g1/library3.jpg

Seems to work with light passing through transparent objects ok, but does it reflect light from reflective objects? I know having a mirror able to reflect light is one of those things earlier Bryce versions have not been able to do. If they fix that, I'd suppose that's a big step.

Not caustics, and nothing faked. It was is a straight render, then in Photoshop;

-Used Bryce distance render to put in a dof (gaussian) blur of 4 pixels in the background, 25% sharpen in the foreground.
-Adjusted the images levels; increased the white & black levels.
-A little grain.

Sometimes...you can get a very slight caustic looking effect, but it is only the light/shadow that passes through the sphere, and since the shadows are soft, it kinda/sorta/sometimes looks something like a caustic.

Sorta like this B5.5 render; Bryce Blues

Bryce, as far as I know, has caustics, but only those resulting from light passing through a refractive body. What Bryce lacks is the reflective caustics, like you'd get on ceilings from the light reflecting from a pool.

Unless bryce 6 has photonic render pass it's no caustics.

I just thought it was something to do with peroxides, acids, or bases..but there's a lot of chemicals around here..;)

Lol....ouch, I got that pakled...painful, but I got it, lol.....;o)

Yep Bryce has always had refractive caustics - just crank up the refraction on a glass object and watch them pop. Erlik is spot on - it is the reflective caustics that it doesn't have and those are the kind that take special sampling algorithms beyond standard ray tracing. Vue has the same kind as Bryce - I think I even have old Bryce 1 renders somewhere that show these little caustics. I also think the HDRI is making them a little more prominent since it is such a refined quality of light.

I remember some ocean or water simulated caustics that Bryce can use. They did look convincing, and I think you can find some MATs here and there for that. It would take photon mapping/area sampleing, I think for true caustics. Does look awesome though. Maybe future versions.

fpfrdn3, there was a program out there for free that renders caustic 2d texture maps for water. I forgot the name but i think it was something like caustics generator, or something similar to that. It's really a pretty effective tool, though it does limit to a very specific effect.

Attached Link: http://www.lysator.liu.se/~kand/caustics/

This is the one.

Quote - Sometimes...you can get a very slight caustic looking effect, but it is only the light/shadow that passes through the sphere, and since the shadows are soft, it kinda/sorta/sometimes looks something like a caustic. Sorta like this B5.5 render; Bryce Blues

Hey AS, it would be interesting to know what - if any - difference Bryce6 makes to the render of that same scene.

Both a basic one (for timings) and one using HDRI - just to see what difference that makes to the look of it.

I can try that out. That was a long scene to render in the first place, tons of transparency, reflection, refractions, soft shadows.

I can experiment later tonight when I get back home. ;o)