Shadows and Shading

Sun-Path Diagram Projection Methods

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Most of the real detail in a sun-path diagram is usually around the horizon. This is where adjacent buildings, trees and other site objects provide the greatest levels of obstruction. To increase detail at these low altitudes, different sun path projection methods can be used to essentially 'squeeze' altitude angles towards the zenith and expand them around the horizon. This applet demonstrates the most common altitude projection methods and shows how they can be mapped in both sky-dome and orthographic sun-path diagrams.

Horizontal and Vertical Shadow Angles

Open /scripts/educational/horizontal-and-vertical-shadow-angles

Horizontal and Vertical Shadow Angles (HSA & VSA) are very important when dealing with the design of shading devices. As opposed to solar azimuth and altitude angles, shadow angles are always taken relative to a particular surface. This applet presents a visual illustration of the complex relationship between location, solar position, orientation, tilt and shadow angle. Interactively changing the date, time and location is the key to developing a visual understanding of this fundamental shading design concept.

The Earth-Sun Relationship

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This applet demonstrates the geometric relationship between the Earth and the Sun, showing the resulting illumination pattern at any time of the day and year for any location. All factors such as declination and the equation of time are fully considered and accurately modelled. It allows you to overlay information such as annual sun paths, important latitude/longitude lines and world time zones. You can rotate around the Earth in any direction or lock into a geo-stationary or view-from-sun perspective. Both annual and daily solar cycles can also be animated to better appreciate subtle effects.

Solar Position and the Sun-Path

Open /scripts/educational/solar-position-and-sun-path

Sun-Path Diagrams are a way of modelling and visualising the path of the Sun through the sky at a specific geographic location. With a little interactivity and a small element of play, such diagrams can significantly contribute to our understanding of how the Sun is likely to interact with a building - a concept crucial to the effective design of shading systems. This applet presents just such a Sun-Path diagram, allowing you to interactively change date, time and location as well as viewing it in a range of different ways.