This is the first object I have made in Curvy 3D that I have saved as an OBJ file. It's part of a larger project I'm working on.
What I did is I made this image in gimp as a height map bmp file:
And I used the inflate function to bring it into Curvy 3D. I also had to resize it making it bacwards.
Then I did the same with this other image from gimp as the bottom:
I had to scale it to invert it and reverse the surface before grouping it with the other side, selecting both while holding the shift key and then stitching them together from the mesh menu:
I really like this program.