Hi RJ, models that have a branching structure with soft transitions like that tend to be easier to do with sub-d modeling rather than with NURBS construction modeling.

So the easiest method would probably be to construct it in c4d using poly modeling / sub-d smoothing there, and then if you need to do further CAD operations on it like booleans you can use the V4 sub-d converter (available in v4 under Sub-D > Create > From file) to convert the sub-d control cage in .obj format exported out from C4D into a NURBS surface object in MoI.

To do this in MoI you would need to use some of the more advanced surface modeling techniques like trimming surfaces and constructing blends, like this:

Trimming to make a hole:







Then you can select edges like this:



And use Construct > Blend to build a blend surface connecting between those edgs:



But can be a fairly difficult process. If you are already familiar with sub-d modeling it would probably be a good idea to build it in C4D rather than in MoI.

- Michael