I am trying to evaluate the location of the sun and whether or not it hits a wall at all times of the year. I am currently using the following four Equinox and Solstice dates: 3/20/15, 6/21/15, 9/23/15, & 12/22/15.
My issue arises when placing a south facing wall in Dallas, TX (latitude = 33 degrees) with the sun at the Tropic of Cancer (latitude = 23.5 degrees) on 6/21/15. What could possibly be the reason that the sun does not shine on the south face of my wall? If the sun is at 23.5 degrees and my wall is at 33 degrees, then my wall is located north of the sun...or more specifically, north of a plum line coming from the sun which would always land on 23.5 degrees.
The source vector is 0", -1/4", 1" but since I don't have a clue what those are representing...x, y, z maybe? Is that the direction I could take to get TO the sun? Is that the direction the sun's rays are moving to reach the earth? Please don't try to explain this with a "Rotate the vector (0, 1, 0) around the vector (0, 0, -1) by the azimuth angle to get the vector (x, y, 0) then rotate that around the vector (y, -x, 0) by the altitude angle" as I am an engineer and not a mathematician. Been too long since dealing with vectors to be able to readily understand all of that. Whatever the case, +x = East, +y = up(altitude), and +z = south in my drawing. And I have set the drawing to understand north in the correct orientation so that is not the issue.
