[Radiance-general] Re: rendering parameters

[John S. An]

Sorry, forgot to mention that the view taken of the image is a plan 
view.



On Jan 4, 2004, at 12:25 PM, John S. An wrote:

> I was wondering if I could get some input from the experienced 
> Radiance users out there regarding rendering parameters.  I am 
> currently rendering an extremely basic room (13.5'x13.5'x14') with one 
> indirect light fixture.  However, accuracy is extremely important.  So 
> I am in the process of running test runs to see what would be the 
> optimal rendering parameters within the time limit I have.
>
> I had been getting blotchy results, so I have been doubling the -ad 
> parameter.  My most recent rendering parameters were:
>
> -i -t 600 -dt 0.04 -dc 1 -ds 0.01 -dj 0.6 -dr 3 -dp 4096 -st 0.01 -sj 
> 1 -av 0 0 0 -aw 0 -ab 3 -ad 4096 -as 2048 -ar 256 -aE 
> ../ambient_exclude -ms 2.7 -lr 12 -lw 0.0005 -aa 0.04 -af b_b_m.amb 
> -ps 1 -pt 0.04 -x 512 -y 512 -pa 0
>
> I did an overture rendering at -x 64 -y 64 prior to creating the image 
> at 512x512.
>
> I am, still getting what I feel to be significant blotchiness.  The 
> image can be seen at:
> http:/homepage.mac.com/jsan
>
> So, my questions are:
> Are there any immediate red-flags you see in my rendering parameters 
> that seem incorrect?
> Do I simply need to keep increasing the -ad to get better results, or 
> would lowering the -pt help both the visual and calculation accuracy?
> If I pfilt the image with -x /2 -y /2, will that merge the values of 
> the pixels enough to make the values at each pixel relatively 
> accurate?
>
> Just as background, this image took about 12 hours to render (with the 
> overture calculations) using rpiece on a dual G5 Macintosh with 1.5 GB 
> of RAM and a 2.24 P4 with 1 GB of RAM.  I have about 200 similar 
> situations to run (more light fixtures, larger room, etc.)  So 
> increasing the -ad to 8192 seems to be prohibitively expensive at this 
> point.
>
> Thanks.
>