PRO 7 Sun orientation

Old forum thread helping with sun issues.

Cindy Cowgirl

8/3/09

To achieve precise shadowing for a building which is not oriented exactly north -south, is it best to;

1) rotate the building to its true orientation (then presumably change axis), or

2) Change the sun (I dont see a option in the Shadow dialog box to do this)

3) Open a new file - import the model and rotate it

Other?

Gully Foyle

8/3/09

Why not just model it on-axis and rotate it when you're done?

-Gully

George Knowles

8/3/09

Hi Renzo,

Pick No. 2)

Establish the correct path of the Sun for your location and orientation by setting the North Angle in SketchUp. This enables you

to keep your model on-axis.

Click … Window > Model Info > Location to set the Solar Orientation - North Angle.

SketchUp bearings are True Direction. There are a few places on earth where True North and Magnetic North coincide … But not many.

Example: Boulder Colorado: 9 deg. 16 min. East Variation

Annual change: 8 min. West per year

If you take field bearings with a compass at the building site, apply the proper correction for local Magnetic Variation to obtain True

Direction.

Local Magnetic Variation (also called Magnetic Declination by those who never venture on the water) can be found here:

http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination;jsessionid=00A94F3B69155DDE7B0E576CA86075CE

How to apply corrections here:

North Question Redux

Best regards,

Geo

Cindy Cowgirl

8/4/09

Nice joe lad, thanks