[Radiance-general] pixel radiance question detailed

[Gregory J. Ward]

Hi ChenGuang,

This is a nice illustration of the problem.  If you rendered these  
with rvu, I wouldn't expect the pixels to match exactly, since the  
actual point rendered is randomly chosen from within each region, and  
using the default parameters of rvu, radiances are only accurate to  
within 15% (see the -pt setting from "rvu -defaults").  This is to  
increase rendering speed.  To avoid sampling discrepancies, you  
should use rpict instead with the following settings:

	rpict -ps 1 -pj 0 -dt 0 -sj 0

Even so, your pixels will only match within 1%, due to round-off  
errors in the pixel encoding itself.  To get better accuracy, you  
will have to use rtrace.

-Greg

> From: "Sun ChenGuang" <suncg03 at gmail.com>
> Date: May 30, 2007 7:49:10 PM PDT
>
> Hi,
> 	Sorry for failing to describe my question clearly. I follow the
> recommendation to make a more detailed description:
> 	
> http://www.drivehq.com/file/df.aspx/publish/scg03/doc/description.pdf
> 	I hope that would be clearer. Thanks.