[Radiance-general] Compute direct component from sky only

[Thomas Bleicher]

On 22.09.2005, at 10:00, nick devlin wrote:


> Dear All,
>
> I am trying to calculate the direct light from the sky for a  
> reference grid within a number of rooms. I am sure there is a  
> sophisticated manner in which to achieve this, but I have cobbled  
> together an approach in the following way:
>
> delete the ground source glow from the sky.rad description
> use rtrace to calculate the values for the points, but set -av 0 0  
> 0 and use a single material for all surfaces (except apertures!)  
> which is excluded from the ambient calculation using -ae.
>

You have to set "-ab 0" as well or ...


> There are some points within the rooms, which I am pretty certain  
> do not have a direct view of the skydome, and therefore should  
> return a zero value, but they do not.
>

... you get indirect contributions from the sky.

If I do understand the discussions on the list correctly you have to  
take into
account _only_ direct components for ie. "Right of Light" and other  
legal stuff.
In reality the indirect components do count as well.


Thomas