Page 1 of 1

Maxwell Physical Sky Sunpath Confusion

Posted: Fri Jul 11, 2008 4:31 am
by guerillary
I'm trying to match Maxwell's sun position to the one in my image plane, so that I can match physical sky lighting conditions of my cg elements to a live-action scene.

The image plane was filmed near the end of June in Malibu, California at about 7PM PST. Per my research, this means latitude = 34.03, longitude = 118.78, hour = 19 and GMT offset = -8.

Furthermore, my camera remains at the origin and hasn't moved since creation. The live-action camera (view of image plane) faces SSE, or near the 160 degree mark of a circle if 0 is North.

My first question is, at the moment of camera creation in Maya, what direction are we looking in Maxwell's physical sky space? True North, or?

My next question is, why does it look like a dark night at 12PM?

Thanks,

Posted: Fri Jul 11, 2008 10:18 am
by Mihnea Balta
Maxwell uses positive longitude values for East and negative for West, so Malibu is at -118. Positive 118 is somewhere in China, and at 12 PM in Malibu China is sleeping. :)

When you create a camera in Maya it's looking down the negative Z axis, which corresponds to Maxwell's North.

Posted: Mon Jul 14, 2008 4:26 am
by guerillary
Thanks, works perfectly now.