By default the SLD to generate a heatmap in Geoserver takes numbers between 0 - 1 to define the color ramp. So this would be a relative scale, where 1 is assigned to the area with the highest value in relation to the rest of the dataset.
I have multiple layers and I want to visualize them on the same scale. Each layer is based on different data, I would like to visualize them on an absolute scale.
For example: I'm using the following color-ramp: green-yellow-red. I would like all area's with a value of 500 + to be red, with a value of 250 to be yellow and with a value of 1 to be green. This means I might have some layers without red, or yellow area's. I want this so I can visually compare the different layers to eachother.
Is there a way to do this, without writing my own rendering transformation in Java?