One year ago I wrote a post on LinkedIn that showed an animation of shadows cast by the buildings of the University of Guelph campus over the span of a single sped-up day. Something about this brief 2-second animation really struck a chord with readers. It is still one of my most well liked and commented upon posts on the platform.
Not many people, however, were aware of the work that went into creating this short animation. The truth is, it was a quite a tedious process. First I generated numerous rasters using WhiteboxTools’ HorizonAngle tool (this part was at least scripted). I then manually displayed the data in QGIS, rendered with a stretched palette to mimic a particular sun position and overlaid a digital surface model (DSM), saving these rasters as individual images. Finally, I imported the images into the GIMP image processing software for the creation of the final animated GIF. This process took a surprising long time but was worthwhile because of how effective the resulting visualization was.
I have some good news for people who want to make their own shadow animation. This whole process can now be completed with the press of a single button! Using the new ShadowAnimation tool, part of the General Toolset Extension for WhiteboxTools, all you need to do is point this tool to a DSM, specify a few parameters, and within a few minutes you too will have your own impressive dynamic shadow model. The shadow models produced by this extension tool are much more sophisticated than the original manually derived animation that I posted to LinkedIn. You can specify the day of the year (the tool calculates the sun’s position throughout the day), time interval, animation speed, and there are even several beautiful palette options available.
Applications of ShadowAnimation
I believe that these animations are more than stunning visualizations; they can provide useful information as well. What are some of the potential applications of this tool? There are many interesting ways in which the ShadowAnimation tool could be applied. For example, using it, you could assess the shading of rooftop solar photovoltaic panel installations within residential neighbourhoods. This enhances the information provided by the TimeInDaylight tool for this type of application.
The visual impact of large buildings could also be examined using the ShadowAnimation tool. This could be invaluable information for planning applications in large urban areas.
You could map shadows cast by windbreaks and forest blocks into adjacent fields to assess the impact on crop yield. This would be particularly useful in precision agriculture applications.
Or the shortened day-length within deep valleys in rugged topography could be estimated. This information could be helpful in managing recreational trails use in mountainous environments. In this way, the ShadowAnimation tool could be complimentary to the AssessRoute tool, also in the General Toolset Extension.
There are a great many ways in which these models could be applied. The tool outputs an HTML file, which allows for zooming and panning in shadow animations, for even greater interactivity. Take a look at the example provided here.
ShadowAnimation is one of my favourite new Whitebox tools and I am excited to see the wonderful ways that you use it. You can download this exciting new tool here. Be sure to let Whitebox Geospatial know when you do have an interesting application. We love hearing about what you’re doing with WhiteboxTools.