SketchUp shadow check
Work out the sun position and shadow of a vertical post from latitude, longitude, date and clock time. Then see how far a wrong time zone or north angle moves the shadow tip.
A cross-check, not a design tool. Geometric sun elevation (no air refraction), level ground, a thin vertical post. The preset values are invented examples.
| Result | Correct settings | With the errors |
|---|---|---|
| Sun elevation (degrees) | - | - |
| Sun azimuth (degrees from north, clockwise) | - | - |
| Shadow length | - | - |
| Shadow points towards (degrees from north) | - | - |
| Shadow tip moves by | - | |
Method: NOAA general solar position formulae (declination, equation of time, hour angle). Shadow length is height divided by the tangent of the elevation. A time-zone error makes the model use the sun from a different hour. A north error turns the shadow clockwise on the screen. A latitude error moves the sun's path. The errors are combined if you set more than one. Numbers accept 51,5 or 51.5. Written as 1.000 or 1,000 they are refused as unclear, so write 1000 or 1.0.