Hi B.Y.O.B.
thank you for your feedback.
Here's the scene setup:
It's actually pretty simple, just the cross itself, a plane that catches the caustics and the objects to create the fill-caustics.
Also there are four very small area light sources below the cross, one for each bar.
I sculpted some beveled edges on it so the caustics would be more interesting and not cast by a perfectly even and planar surface.
And in general all light sources that cast caustics are really small area light sources so the caustics would be nice and sharp.
Here it is without the caustic in the lower right:
One technical thing: on the left and in the bottom the last pixels are completely white, which I would not expect. Therefore I had to increase the render size by three pixels an cut that off afterwards.
Great thanks also for the light-tracing feature, it's really, really helpful for caustics rendering.
However it appears to me that it doesn't work all right, the caustics seem to be way too bright.
Bidir + Metropolis reference:
Path Cpu + Sobol:
Path OpenCl + Sobol:
All three use the same linear tonemapping.
It would be super awesome if that could be fixed, because light-tracing is such a great way of rendering caustics.
