Hi Andrew,

re:
> So, it seems that you are saying to leave that step out, i.e. to open the drawing in
> CorelDraw, clean it up and save it straight to a PDF. Correct?

Yup, that's correct. Basically for any transfer from CorelDraw to MoI use PDF format for the transfer instead of DXF. But when transferring from a 2D CAD program to MoI that's when DXF would usually be preferred.

The problem happens with curve segments in CorelDraw (and other 2D illustration apps) that have a tangent handle on one side but none on the other side. That makes a bezier segment of 4 points but with 2 points stacked up on the non-tangent-handle side. Most 3D CAD programs do not like to have that kind of stacked up control points on curves, it kind of degrades some of the mathematical properties of the curve at that spot.

When MoI opens a PDF file or AI version 8 file it will look for those and tweak them slightly to avoid the stacked up control points. It doesn't do this for every kind of file open because that tweaking does make for a very small change in shape and usually MoI tries to be pretty conservative and avoid modifying things that changes the shape of things at all.

- Michael