Several issues for the Terrain Tab
I recommend the following changes:
1 Change the Point Buttons from 'P' to 'Ph" for high and 'Pl' for low, or some other designation. (I will probably never use any of the sliders.)
2 In the angle text boxes, I'd set both defaults to 90 degrees. This will prevent accidentally painting the whole terrain with whatever terrain type is selected.
3 Most importantly, the Apply to All Terrain button should be dimmed and unselectable until at least one of the Enable check boxes is set.
Issues causing these suggestions:
When the TE first opens, or if you come back to the Terrain tab after making changes, and you click the Apply to All Terrain without changing any of the default settings, the whole terrain will be painted with whatever terrain type is selected. As there's no Undo for this, previous work since the last save will be lost.
When using the Enable Altitude Filter, if you use the Point buttons to set the Low and High point, and then click the Apply button without first setting the Enable Altitude Filter check box, the whole terrain is painted with whatever terrain type happens to be selected. I don't think either the Angle filter or the Altitude filter is causing this.
Unfortunately, the Undo command appears not to work with either of the filters, Altitude or Angle. Considering the global nature of the filters, I don't expect undo to work but this makes 'idiot proofing' for me, more important.
The default setting for the Angle range is zero to ninety degrees. I think I'd recommend changing this to ninety ninety. This way the whole terrain won't accidentally be painted if the Enable Angle Filter is set with the default values.
If I wanted to actually paint the whole terrain, with snow for instance, I could set the Altitude range from zero to thirty thousand feet, or I could set the Angle range from zero to ninety degrees.
