Merge Heightmaps

This dialog allows the user to merge together height values in two heightmaps. 

Destination Heightmap: the result of the merge will appear in this heightmap.

Destination Height Scale: displays the current height scale for the destination heightmap.

Source Heightmap: the source of height values to merge into the destination.

Destination Height Scale: displays the current height scale for the source heightmap.

Merge Method:  specifies how the height values will be merged.  Choose from:

• Replace - replaces all the heights in the destination with ones from the source
• Add - adds all the heights in the source with ones from the destination
• Subtract - subtracts all the heights in the source with ones from the destination
• Average - averages the height values from the source and destination heightmaps and places those into the destination heightmap

Relative Height Scale: when unchecked this shows the current relative height scale between the source and the destination heightmaps.  When checked, the user can specify the relative height scale they wish to use when merging the heightmaps.