TheSwamp

Code Red => AutoLISP (Vanilla / Visual) => Topic started by: GDF on June 22, 2018, 08:15:43 AM

Title: Draw Sun Angle in Plan
Post by: GDF on June 22, 2018, 08:15:43 AM

I'm fishing for a lisp routine that will draw in plan the sun angle based upon AutoCAD's Geographic Location palette settings.

Title: Re: Draw Sun Angle in Plan
Post by: GDF on June 22, 2018, 08:34:30 AM

I have found this tool:
http://andrewmarsh.com/apps/releases/sunpath2d.html

Title: Re: Draw Sun Angle in Plan
Post by: huiz on June 22, 2018, 10:01:39 AM

In 3D even prettier:


http://andrewmarsh.com/apps/staging/sunpath3d.html

Title: Re: Draw Sun Angle in Plan
Post by: GDF on June 22, 2018, 01:36:14 PM

(defun C:SUN1 ()(command "start" "http://andrewmarsh.com/apps/releases/sunpath2d.html")(princ))
(defun C:SUN2 ()(command "start" "http://www.sunpath.in/#/29.1617,-82.1779,12/2018.06.22/13:51")(princ))

Title: Re: Draw Sun Angle in Plan
Post by: GDF on June 24, 2018, 12:27:26 PM

Ok, you math-trig masters:

What I am trying to achieve is the approximate shadow angle calculator for a vertical wall... solar zenith angle. by plugging in the necessary variables.
(hopefully I'm expressing this correctly)
Lattitude =
Time of day =
Month =

To get the solar zenith angle

Can anyone help me with a calculator formula example?


;;;https://en.wikipedia.org/wiki/Solar_azimuth_angle#Formulas

Title: Re: Draw Sun Angle in Plan
Post by: huiz on June 24, 2018, 02:47:30 PM

You can download an Excel file here:


https://www.esrl.noaa.gov/gmd/grad/solcalc/NOAA_Solar_Calculations_day.xls


Fill in the location and date and it will fill everything you need. Formulas are in the cells.


Be aware of the theoretical results, For really accurate calculations you need to respect the influence of the atmosphere, true north and the elevation of EG (or bumpy terrains). I think a few degrees are acceptable for theoretical calculations.

Title: Re: Draw Sun Angle in Plan
Post by: GDF on June 24, 2018, 03:04:30 PM

Thanks

I'm also looking for additional drawing files from different latitudes like the one enclosed for London: