Hi niko, you'll need to use the Move command for that particular case of wanting to move a curve control point while referencing other curve control points.

While dragging curve control points, snapping to other points on the same curve is suppressed. Otherwise it is too easy for points to kind of stick together and cause points to get doubled up over top of one another.

However if you use the Move command instead, that will allow for snapping on to curve control points so it should do what you want.


To make a point be positioned in a straight line between 2 other points, you can create a construction line by clicking on one point and dragging and releasing on the other point. That will form a temporary construction line you can use to snap on to.

Here's a quick screencap to illustrate:



The key thing in there is the creation of the construction line - again that is done by clicking and holding down the mouse button where you want to place the start point of the line, and dragging away, and then releasing on the end point.

That forms a construction line which is a very useful snapping guide for all kinds of operations, you can use it for extensions, intersections, finding the midpoint between any 2 points, capturing a distance and positioning it elsewhere, snapping to intervals like 1/5 between any 2 points, pulling points up in z while in the 3D view, mirroring points around an axis line, etc...

For more details on what is possible with construction lines, see here:
http://moi3d.com/1.0/docs/moi_command_reference10.htm#constructionlines

That's kind of a key thing to get used to in MoI to get the most out of its snapping system. Once you get used to it, I think you'll see how powerful it is. Another really nice thing about it is that it stays out of your way completely until you specifically call on it with that "hold and drag" gesture.

- Michael