There are some issues with the Terragen .ter and Bitmap .bmp file formats exported in World Machine.
According to the Terragen file format spec (http://www.planetside.co.uk/terragen/dev/tgterrain.html) the SIZE chunk value is supposed to be “n-1”, where “n” is the number of data points on a side (ie. horz or vert heightmap resolution).
So for a heightmap that is 256x256 (0x100) the SIZE chunk value is 255 (0xFF). For a heightmap that is 128x128 (0x80) the SIZE chunk value is 127 (0x7F).
World Machine is incorrectly writing the SIZE chunk value as “n” and not as “n-1”.
This causes WM .ter files to error on various applications that validate the header values to the total size (W*H) of the ALTW heightmap data chunk.
I still have to look at the .bmp error. I’ll post back with the information soon.