Setting background image scale

 From:  Supagoat
6428.1 
Hi there. First off, I'd like to say another big thank you to Michael. I've just purchased a license and on the one hand I'm thrilled to be using MOI, on the other I'm also amazed at how difficult to use pretty much every other package is in this day and age.

Anyway, I have 2 questions at the moment. I'm currently modelling a case that I plan to 3d print for a real world object. I took pictures of the object from 3 sides and have brought them into MOI. I sized them by eye and have got them right, but I was wondering if there was an automatic way to scale them. For example, Autodesk Fusion 360 has a feature to scale background images where you draw 2 points on the image and then enter what the distance should be between them and then it scales the image to that size. It's very handy.

My second question is about the numeric entry area at the bottom and its uses. I can make it do some things I want, but it's not clear to me how to do something like reset an object if I don't like the things I've done. Like if I draw a line, then rotate it arbitrarily, and then want to reset its rotation to how it originally was... It's not clear to me how to do that. If it was at a simple angle like aligned with an axis I can grab a modifier corner and it seems to scale and rotate at the same time and I can snap it to where I want and then I can re-set the length numerically but that doesn't seem to be the right way to do it. Alternatively I can click the rotate arrow but that enables free rotate and that doesn't scale, but it also doesn't seem to snap to grids or objects.

Thanks!