[Becco_UK]

I saw another recent post about Maxwell Beta not producing caustics with sunlight and decided to produce a few quick renders myself to see the nature of the reported problem.

I encountered no problems with producing caustics using sunlight as the light source.

However, the shadow seems to be wrong - it does not lighten. The solid diffuse sphere casts the same shadow as a dielectric sphere - this does not seem to be correct.

Also, what has happened to spectral dispersion? In the alpha version of Maxwell spectral dispersion appeared very quickly and was refined over time. Now it does not appear.

Is this why the Beta is supposed to be faster because it has stopped calculating accuracy?

[Becco_UK]

Adam: I couldn't make up my mind about the accuracy of the caustics so I didn't pass any comment on that. If the sun shines here tomorrow I will use a real life glass tumbler and compare the real caustic pattern with a Maxwell render.

[Tyrone Marshall]

Adam: I couldn't make up my mind about the accuracy of the caustics so I didn't pass any comment on that. If the sun shines here tomorrow I will use a real life glass tumbler and compare the real caustic pattern with a Maxwell render.

Becco, why don't you use matadorlight as a comparison to see if there is a different between the two (cinemaxwell and matadorlight)? You should get either two similar renders or two different renders.

[rivoli]

those caustics don't look correct to me, i had similar results with dielectrics and sun light casting weird caustic patterns.

as long as i can tell they seem to work right with emitters.

[Maximus3D]

That caustic band looks like the smoothing angle of the phong tag set in C4D, probably if you change the smoothing angle the caustic effect changes too..
But i could ofcourse be completly wrong hehe

/ Max

[Tyrone Marshall]

What phong angle are you using?

I know I read something in the release notes that said something to the affect that in cinemaxwell the phong angle limit is 60 degrees (so do not use phong angles greater than 60 degrees at this time).

Is this something you could look into?

[jotero]

Spectral Dispersion Problem?

no :*) winosi_cuba test maxwell beta 1.2


http://www.maxwellrender.com/forum/view ... i&start=30

ciao
torolf

[Becco_UK]

Thank you for the above comments.

I lowered the value of the phong angle and it made no difference.

Taking into account the replies: This morning I carried on a little bit further and made a couple of Maxwell images.





This one uses a single polygon emmitter. I still can't decide about the developing caustic pattern but it does seem better than the sunlit versions. However the shadow shows no sign of brightening.




Using MatadorLight produced this. The shadow problem is still there. The lack of caustics may be down to MatadorLight. This little test isn't conclusive though because of different camera angles and the lighting came out brighter in Matador (same settings used).

Caustics aside, the dielectric shadow problem would seem to down to the Maxwell Beta engine and not related to plugins.