I thought Archicad users might be interested in a method for creating a shadow study rendering with more than one sun position.
Technique as follows:
I have managed to work out how to do 3 shadows in one render eg Mar 21 for 9.00 am, 12.00 noon and 3.00pm as per the image below.
Basically you use 3 Lightworks sun objects, progressively changing the system sun time/date and then editing each sun object in turn to set them to manual which defaults to the current time/date sun position. Also set diversion angle to 0 degrees to achieve hard shadows. Then I change its light colour alternatively to red, yellow and green.
I then render (in Lightworks) with lamps only using hard shadows. This methods lets you cut down the number of sheets to show shadow diagrams by two thirds assuming you need to do March 21, June 21 and September 21) and make it easier to compare.
Consider this technique the bastard son of Dwight Atkinson's "undersun" object pioneered for Archicad 9.0. This makes sense if you purchased his book.
This method with a bit of work could be adapted to shown shadows for the same time during different days of the year too.