[Radiance-general] Curved Longitude Lines - Raytracing Brain Teaser

[Lars O. Grobe]

Hi David,

I did not really get what you really want to achieve. What kind of a sky 
coordinate grid are you refering to? It looks like you want to create a 
projection of the longitudonal lines of a hemisphere, right? What 
projection do you refer to when saying hemispherical view? What I see on 
the image looks a lot like a parralel proction of the dome, so the 
lines's coordinated could be calculated from spherical coordinates, 
obtained from the horizontal and vertical angle and radius, and ignoring 
the third coordinate (for the image you just need the two dimensions), 
transfered into cartesian coordinates. If you write down the formulas 
for this, you should be able to combine to something much simpler 
describing the parabolic curves. But I am not sure if I really got your 
intention yet.

So do you want a parallel projection of a hemisphere with longitudonal 
lines?

Lars.
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