Hi Rudl, so probably the best way to get the same kind of trim done in MoI would be to build a sort of ribbon cutting surface from your curve.

To start with, move some control points to get your curve positioned around the object - it doesn't have to be exactly on the object in fact it's better if it is not and just kind of goes a little around the outside of it something like this:



See the attached 3DM file camera2.3dm to see the model of these curves.

Then draw a small line at the bottom here:



Select the line and run the Construct > Sweep command - that will build a surface that looks like this:



You can now mirror and join that surface to get this:



See the attached Camera3.3dm file for the model of the above.

Now that you have a cutting surface in place you can use the Trim command - select the main camera body, run Edit > Trim, and select that ribbon surface as the cutting object. Then pick the piece that you want to discard and you will end up with this result, which I think is what you were looking for:




One other thing to note, later on in this tutorial it looks like it uses Blends - currently MoI's blend command is pretty basic compared to Rhino and you can only blend between 2 edges at a time. So if you have a long string of edges it can be kind of difficult to do that in MoI, you need to use the Trim command (with the Add Trim points option) to cut any long edges up into pieces so that you can match them up in pairs. Instead of using Blend in MoI it can be better to use Filleting when you are dealing with a long chain of stuff. For filleting you need to make pieces that are actually touching instead of having open space in between them like you do with Blend.

In the future I do expect to enhance Blend to work with longer sets of edges instead of only 2 at a time.

At the moment though if you expect to do a lot of blending like this you might want to use Rhino for that instead.

But anyway you can use the above ribbon cutting surface technique for getting the type of trimming that you want inside of MoI.

- Michael