Hi Radiance community!
I am an indirect user of Radiance, meaning that I have only used it through Honeybee, and unfortunately I think I lack some basic understanding about how things work. My question is probably simple, but I got a bit lost with all the information on the Radiance website and I thought that maybe someone can explain it to me in an easy way.
I want to ask about the interpolation in rtrace. I want to calculate radiation on grid points that I defined on a building facade (specifically, I have 560 points). I have noticed that when I turn the interpolation off by setting aa to 0 the time reduces rapidly, but I get an error. Then, with aa 0 if I reduce the lw to something close to 0, I get accurate results in a very short time. Do you think that this makes sense? Or am I doing something wrong? I lowered the lw because I read some comments by @Greg_Ward on this forum saying that aa 0 might be a good idea for calculating a few points but you need to be careful about your other parameters.
Then, my general question is why do I need the interpolation when I want values on some points? If I understand it correctly, when it comes to picture rendering I want the interpolation so that I don’t calculate a value for every pixel. But when we are talking about grid based analysis what is the interpolation doing?
Thank you for the help!!