Hi all, I am working to create an animation using temporal GPS data. The data ranges over 8 months and I show a span of 7 days with a step interval of 2 days. I would like to make the older points become partially transparent over time as the animation progresses, but am struggling to find the right expression. I am using the expression builder under Vary symbology by attribute, Transparency. I believe it should read as:
DateDiff($feature.point_datetime,XX)
The first feature is the datetime of the point and the XX should use the startTime or Map Time but I am unsure how to use this as a variable in the expression and my many searches have not found the answer.
Any suggestions would be greatly appreciated.
