The mask editor allows the user to specify regions of the main heightmap. These can then be textured differently in the texture generator dialog.
Pan: Move the heightmap with the left mouse button when this is active.
Extents: Zoom to fit the heightmap to the window.
Zoom In: Increase the zoom level. This allows more accurate selection of regions on the heightmap.
Zoom out: Decrease the zoom level.
The mouse wheel will also perform zoom in / zoom out functionality.
No Water: Show no water
Water: Show the pixels covered by water.
Underwater: Show the regions underwater.
Main View: Shows the selected regions in yellow of the mask on top of the main heightmap.
Result View: Shows the selected regions of the mask only.
The following tools allow the user to select various areas of the heightmap for inclusion in the mask heightmap layer. The allow several modes.
Absolute Height: when the pixels are selected, the mask contains the values at the specified height from the entry field.
Copy Height: when the pixels are selected, the mask contains the values copied from the heightmap plus the adjustment value.
Undo: Allows the previous action to be undone.
Redo: Allows the previous undone action to be reapplied.
Freehand: Select pixels by holding down the left mouse button and moving the mouse. The amount of pixels selected is specified in the line thickness entry field.
Lines: Press the left mouse button and hold then move the mouse the generated line will show on the view. Release the mouse button to confirm the line position. The width of the line is specified in the line thickness entry field.
Closed Shape: Press the left mouse button and hold then draw around the shape you wish to enclose with the mouse. Release the mouse button to add the shape to the mask. The tool will automatically close the shape by drawing from the first position to the last position, so the user does not have to worry about getting back the exact start pixel. All the pixels within the shape will be selected based on the current tool height mode.