[Radiance-general] Re: rendering parameters

[John S. An]

Greg,

That did the trick.  The geometry above the luminaire was the cable 
which would suspend it.  I simply removed it, and all seems fine now.  
I feel so stupid, I spent an entire week increasing the -ad parameter 
and not getting anywhere.

For my purposes, it is ok to remove the cables at this point from the 
model.  However, for suspended light fixtures, it doesn't seem possible 
to ever create an illum that would encompass everything including the 
cables without having the illum sphere touch up against the ceiling.  
This would be more for indirect fixtures than for direct fixtures.  If 
I needed to keep the suspension cables in the model, what would be the 
most proper way of defining the light source?


John


On Jan 6, 2004, at 3:12 PM, Greg Ward wrote:

> 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
>