This shader uses the tree currently displayed in the main tree display as a reference to shade species.
Species at the top of that tree will be shaded with the "low" color, species at the bottom with the "high" color of the active color-range.
The intented purpose of this shader is comparing two tree topologies. To do that, display one of the trees in the main window, then open a second treeview using "File/New Window" and display a different tree in that window.
The tree in the main window will always be shaded continuously.
Shading of trees in other windows will be non-continuous where their topology differs from the topology shown in the main window. This facilitates the detection of topology differences.
The granularity of topology shading depends on the size of the reference tree. Therefore modifying the settings in section 'Value phasing' is strongly recommended while comparing topologies:
to detect local topology differences, increase the phasing frequency until adjacent species are displayed in distinguishable colors. Then use either of the phase-shift sliders to shift the shading.
to detect global topology differences, decrease the phasing frequency.