Thanks those tips makes a world of difference in aligning the background images.
About reloading a background images, for me its really easy...
I have no trouble reloading whatsoever, in fact I usually trace everything without having to reload at all (Keeping and working with basic very shapes and refining it later once the background is gone)
What I do, which appears to make reloading (If I have to, which is seldom) easy is first I set the grid size to a dimensional scale that I will be working with; for example for inches I set the "draw grid major" at 1.2 and this in turn gives me a 12 inch grid spacing instead of tenths.
If I need extremely high accuracy I plot things first in a CAD program and import that into AC3D...
Next I draw grid over on my drawings or photos to scale (Easy to do in Paint Shop Pro or Photoshop or a CAD program). This makes repositioning a background image in AC3D a snap, meaning it only takes only a few seconds, as all that is required is to mate with the AC3D grid boxes with the grid draw onto the a background image.
Could be this is nothing new, and probably everyone already knows this kind of stuff, but I'm just learning my way around in the program. Great fun!
