Idea that the value vs "relative difference" balance of heatmaps can be resolved by using a constant brightness color scheme (e.g. default ggplot hue wheel, making sure endpoints are different), and orthogonally using shadows / 3D to give the overall depth perception.
This should allow more precise matching of absolute values to a scale, while also giving an overall relative sense of depth.
Idea that the value vs "relative difference" balance of heatmaps can be resolved by using a constant brightness color scheme (e.g. default ggplot hue wheel, making sure endpoints are different), and orthogonally using shadows / 3D to give the overall depth perception.
This should allow more precise matching of absolute values to a scale, while also giving an overall relative sense of depth.
Isometric or not?