I’ve started to use this plugin as I can really use this in my work, part of which is about presenting ideas to clients, and as I enjoyed the process so much, thought I’d share how I did it!
All the maps are from the Ordnance Survey open data, which makes this possible (Vector Map Local Raster and Meridian). The data for the train is all my own and is based on actual known information on the Pendolino: the length of the train is to scale; the movement is based on how long it takes, at full speed, to pass you (4 seconds).
The first thing you need to decide is the time step that will best represent your idea, as this needs to be set in the parameters, for this one I chose seconds (see above).
The object of this exercise was to show the movement of a train along the actual line – this technique could be used to represent any vehicle movement, I’ve created a second train which runs east to west at the same time as this one and shows their relationship, the second train is a slow train and stops at the station for the required time – the options are endless, only the complexity changes, anyway, back to the technique!
For the Pendolino I digitised the line to the overall length I wanted it to run and then divided this into an equal amount of divisions based on the length of the train (you could do this using time) now, I have to admit to using MapInfo for this as I’m familiar with using their in-built tool to split lines at equal distance, but if you can do it in QGIS then all the better. The resulting table has three columns: ID, TIME & ETIME – the ID column is important (for my process) as it is the link between the values in the spreadsheet (see below) and the graphic objects. I bring in the values from the spreadsheet and update the graphic table with the time values using a join on the ID. The reason I do it this way is because it saves having to type lots of values individually.
Next, I created the time values in a spreadsheet as this is an easy way to increment the seconds, the starting value is given a date and a time in the format yyyy-mm-dd hh:mm:ss (you can change the format in the Time Manager settings but it is easier to use the default). Each end time was the start time plus 3 seconds, this means that you see the the marker disappear and then reappear giving the illusion of movement along the line – it’s really that simple. So the data looks like this:
ID: 1 TIME: 2012-08-01 00:00:00 ETIME: 2012-08-01 00:00:03
ID: 2 TIME: 2012-08-01 00:00:04 ETIME: 2012-08-01 00:00:07
Open the resulting layer in QGIS and set your line style to your preferred style. Run the Time Manager plugin and click the settings button. Add the layer into the layer box (if you have more you can add those too) and set the other options – you can use the same as mine below:
Once you’ve done this just click the (circular) button to turn it all on and select > and you’ll see your animation working.
A video is now available on YouTube: http://youtu.be/c09agy3FYBk
I haven’t got video for WordPress but below is a series of stills which hopefully illustrate the above:
All images Crown Copyright & Database rights 2012
I hope you get the gist!
I’m working on showing the development of a city and will post the process when I have time.