Hi Supagoat, for your image part, check out the part about the "Align" image option in the linked discussion above. That allows you to do the kind of registration that you're asking about, with picking 2 points on the image and then 2 points in the model to match them to. That can control both rotation and scale as well. For making it a specific distance, either snap the model reference points onto a line that you've already created of the proper size, or you can also use distance constraint for picking those 2 points by typing in your distance value and then the second point will be placed at that distance from the first one.


> Like if I draw a line, then rotate it arbitrarily, and then want to reset its rotation to how it originally was...

In this case you could just use Undo to go back a step if you put in the wrong rotation.

But objects in MoI do not have any sort of in built "base position" to them so if you need to rotate something back to some specific position you would generally use the Transform > Rotate command and snap the first reference point onto the endpoint of the line, and then place the end reference point at the position you want.

If you have something like a line that's just pointing in some non-axis-aligned rotation and that particular rotation is important for you, it's probably best to save a copy of that line so that you can load it right back into place later on.

Generally the edit frame is the convenient and quick way to do transforms, but also the tools on the Transform menu on the side pane give you some more detailed options for doing something specific. Like the Transform > Rotate can make it easier to pick each significant point that controls the rotation (the origin, the anchor point and the target point) with individual picks.

- Michael