Hi Mike, if you want to place a point at a precise x,y,z coordinate you can just type that value in when MoI is asking you for a point.

See this recent thread for some more details on numeric input: http://moi3d.com/forum/index.php?webtag=MOI&msg=5294.1


> F.e. I make a circle with 10cm and a second circle with 5cm and later, I
> want to place the second circle 8,34 cm above the first one.

Use the Transform > Move command for positioning objects precisely:




When you run the Move command it will ask you for base point to pick on the object and then a target point for the location to move to.

For the base point on the circle you would pick the center point of the circle, make sure you have Object Snap enabled in the bottom toolbar so you can snap on to it.

Then when you pick the target point that will be the point the center will be moved to.

To move it directly above another circle like in your example it's easiest to do move in 2 steps - first do one move to move it directly onto the other circle's center point so that they have a shared center. Then do a second move and when picking the target point on the second move type in your distance value of 8,34 and push Enter and that will activate "Distance Constraint" - now the target point will be constrained to be that particular distance away from the base point and then move your mouse vertically and you can then place the target point that particular distance away from the other circle's center. Make sure you also have "Straight Snap" enabled on the bottom toolbar as well so that you get vertical and horizontal line snapping.

Please let me know if any of this is still not clear.


You can also use a construction line to help you place the target point all in one single run of the Move command rather than doing 2 moves. To do that you would need to activate distance constraint and drag out a construction line before you pick even the first point in the Move - that will then make a construction line with a snap point on it for the point you want. Construction lines automatically disappear when the current command is finished so they can be convenient to use anytime you were thinking that you might need to temporarily draw a line to help get you the snap point you need. See here for more info on construction lines:
http://moi3d.com/2.0/docs/moi_command_reference11.htm#constructionlines


> Or, how can I "later" change the size of a circle-spline by entering/changing the radius?

When you select the circle, the radius will show in the properties panel in the upper right area of the main window:



Those different things in the properties panel are also editable, click on any of those things and it will open up an edit panel, you can then type in the new radius value and push Enter to change the radius:




Hope this helps!

- Michael