I have a data variable associated with geographic locations that I would like to visualize on a map. The data is a continuous variable which I’d
like to visualize as something like a contour map. An example data variable for this type of
visualization would be current rainfall, where the map shows different
color levels to indicate how much rainfall is going on. Where the amount of rainfall is below a
minimum, the map shows no color overlay.
I have not seen this type of visualization in the code
examples or seen a discussion on how to accomplish this. I’d like advice on the strategy to take in
Cesium for such a visualization.
Here are the requirements I think need to be fulfilled:
Ability to shade regions of the map with
different colors determined by corresponding geographic data variable. There would be a finite number of colors (perhaps
12 or so).
Colored regions must be transparent and allow
underlying map imagery/labels to be visible.
Colored regions must be able to take jagged
shape, including “islands” of one color within a band of another color
Colored regions must be clamped to terrain
Visualization must be able to update in response
to new data (i.e. this is not a one-off static map)
Nice to have: ability to click on a colored
region and see corresponding info appear in info box
I have so far explored two strategies for this:
Defining polygons with holes for each colored
Overlaying an image file
The polygon approach has worked well for me, but I have only
used simple test data where the contours are well behaved. I am concerned about how this will scale with
irregular data that has “islands” and sharp jagged edges.
I have also tried the image approach, where I overlay a
static image. My main concern with this
approach is that it seems to require I generate an image file to specify the
overlay, when I prefer to use my data directly.
I am unsure if I will be able to dynamically create image files
on-the-fly. In addition, using an image
does not satisfy requirement 6.
I appreciate ideas on how to approach this. I was hoping there would be a high level API
to display arbitrary georeferenced data as a colored visualization,
but I have not seen one. Is the polygon
strategy best? Or is there another API or
strategy that I should consider?