[Radiance-general] Re: rendering parameters

[Greg Ward]

Hi John,

I don't really have time right now to look at your input files, but it 
seems that your problems are associated with the light source sampling. 
  Specifically, the original image with the single fixture seems to have 
some kind of geometry in front of it, which is going to cause 
randomness in the shadows produced.  You should either get rid of this 
bit of geometry (looks like three vanes of a fan) or use an illum 
without such obstructions in front of it.

In the second case where you have many sources, what you are seeing is 
the result of the direct jitter.  If you set -dj 0 these artifacts 
should disappear.

-Greg

> From: "John S. An" <whollycow@mac.com>
> Date: January 5, 2004 2:40:33 PM PST
>
> Regarding the problems I am having with simple room rendering, I have 
> zipped and placed all the .rad, .mat, and control files at the same 
> address (http://homepage.mac.com/jsan).
>
> Also, I finished rendering another image of a room twice the size of 
> the original (13'-6 x 27') and with 18 bare bulbs.  This time, there 
> is a weird moir�-like effect in the rendering.  All of the parameters 
> were, for the most part, identical to the previous case (the only 
> changes were that I upped the -y parameter to 1024 to account for the 
> larger room).
>
> Any ideas as to what is going wrong?
>
> John An