Welcome to the personal website of Dr. Andrew Marsh ...
This site is basically my online notebook, containing an eclectic mix of ideas, discussions and experiments in building performance analysis, generative design, computer programming, data visualisation and web development - all organised under the following two primary themes:

## Real-Time Dynamic Daylighting

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Understanding the potential distribution of daylight in a room is a really key design skill. This applet lets you interactively manipulate windows in a room and see the daylight distribution recalculate and update in real-time. This really highlights the cause-and-effect relationships involved and helps develop that understanding. In addition to just showing daylighting, you can also overlay daylight factor protractors or frequency distribution data and see the effects of different surface reflectances on internally reflected light.

## Simple Parametric Modelling Experiment

This applet is an experiment with parametric modelling. The primary focus was the development of an interactive parameter class with a securely bounded range, variable precision, detailed string formatting, tweening/animation support and direct bindings to both the slider and 3D model classes. The result is a simple parametric tower model. This is relatively simple geometry, but I am really quite surprised how fast Java-based graphics can actually be, and this isn't even using OpenGL.

## Cosine Law and Surface Incidence

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Surface incidence is governed by the Lambert cosine law. This states that the relative intensity of radiation or light on a surface is equal to the cosine of the angle of incidence, and that the relative area over which it is distributed is the inverse of this value. This applet provides an interactive and highly visual demonstration of this effect on both horizontal and vertical surfaces. You can interactively drag altitude and azimuth angles to see changes in both the distribution area and relative intensity of an incident energy beam. It is particularly interesting to see these effects simultaneously on both surfaces.

## Sun-Path Diagram Projection Methods

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

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

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.

## Interactive 3D in a Web Page

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This page discusses the results of my experiments with Processing over the Christmas break. What is interesting about Processing is that it allows you to create fully interactive 3D applets embedded in a standard web page on any platform. For visualising and playing around with complex concepts, this offers something far more exciting than even Adobe Flash.

## Graph - Robustness Calculator

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A significant problem in the performance analysis of buildings is trying to understand hugely complex data sets that often results from the investigative process. These types of analysis are usually focused on the potential effect of different design parameters on the performance criteria we are designing to meet. The type of graph described here provides a simple means of interactively investigating and visualising complex relationships that may exist within a large number of calculation runs.

## Workshop: Mastering Performative Design with Ecotect

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I will be presenting a research workshop at the ACADIA 2009 conference in Chicago on the 20th-21st of October 2009, to be held at the School of the Art Institute of Chicago (SAIC). The aim of this workshop is explore the boundaries of generative and performative design using Autodesk Ecotect Analysis, Green Building Studio and Revit.

## Master Class: BIM & Building Performance Analysis

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I will be presenting a master class at the Design Modelling Symposium in Berlin on the 5th-8th of October, 2009 at the Universität der Künste. This will cover the use of BIM data for a range of different types of performance analysis and the best ways to convert and transfer what you need.

## Stung by Drupal's Filter Caching, Again

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When will I ever learn? I just lost another few hours of my life because - again - I didn't properly understand Drupal's filter cache system.

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When displaying a list of node teasers, Drupal includes a 'Read more' item within a list of links at the bottom of each node. Other items in this list include links for adding comments, the number of page reads and other node-specific actions. For users not familiar with Drupal, this link can be easily missed, making it not particularly obvious that there is more information available.

## Graph - Annual Temperatures (Google Charts)

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The graph is one of my experiments with Google's Visualisation API as a possible means of interactive web-based data presentation. It's an implementation of an annotated time line graph that Google originally developed for showing stock exchange data - used here to show annual hourly air temperature values. It contains a whole year worth of hourly temperature data for San Francisco, so it can take a little while for the graph to appear.

## Graph - Annual Temperatures (Java)

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This graph is an experiment with the use Java applets to provide highly interactive charts and graphs embedded within a web page. It is just an example so the data it shows is not hugely meaningful - in this case a set of annual hourly air temperature values. However, it is an opportunity to play with my primitive attempt at an interactive and intuitive date range control. This control sits at the bottom of the chart and provides a means for selecting a date range for the values shown.