Lightflow : please help me

(hannibar) #1

I have a few problems in this picture :

  1. Under the glass there is a black circle. How does it come there? There is no circle object or so under the glass.

  2. How comes I don’t get caustics through the glass? I watched other sources, and I don’t see much difference in the glass setup then in mine. The interface is set up correctly too (i think).

So how can I resolve those problems?
The .py file is attached on the page.



(fullback) #2

I am certainly no expert but I think the problem might reside in your “Glas” material transmission line.

Transmission is actually “fake caustics”(or at least it is in MATSpider), and having both fake caustics and real caustics in the same material tends to cancel out any noticeable effect.

Try deleting the “transmission” line entirely and changing the “radiosity” parameter from 0 to 1. This worked for me on several occasions. Also, if you are using any kind of GI or ambient lighting, like Eeshlo’s WORLD LIGHT option, it will make caustics difficult to pick up on a surface unless the intensity is very low.

You already seem to have a better grasp of the program than I do, and I have been pestering people for a while, so don’t give up on it. By the way, that is a nice picture — I bet it took a bit of time to render.

You also might try out Mrmunkily’s tut – look at his glass parameters closely.

(hannibar) #3

I indeed used aWorld Light, I think I’ll place another ‘normal’ light to produce the caustics.

The pic didn’t render THAT long. It was about 1.5 hours, and I think that’s quite ok for a raytraced image.

Thanks for your help.