Did not work with C drive Moi.
Did work with Moi on USB drive.

For a surface from test flora.bmp, converted with photoshop to jpg and png,
The png gave much better result, but the picture file size was 4 times larger.
The 3dm loft of the png was slightly larger than for the 3dm of the jpg.
The png is on the right.

zsurf4 uses bmp. The heightmap version, lofted, was very much better than the zsurf4 ersion, IMHO.

- Brian