Keith -

Here are my settings:

When performing the Subdivision step, set the slider to 100 and do not check High Quality Mode.

OBJ file format export settings from MoI:



If you post your 3DM file I can see how it looks in my render program, KeyShot. That can help isolate to either MoI or the render program.

I did see some minor ripples in my model early on, but not sure what caused them or why they went away. I strongly suspect some points may have not been in a straight line and the zig-zag caused ripples. Look at your points in all views and make sure everything is smooth and simple.

Also, do not use High Quality Mode when subdividing. My model looked the same either way, but suspect it will have (at least for my model) a better mesh in normal quality.

Ed Ferguson