Marble Madness

 From:  Michael Gibson
3803.10 In reply to 3803.9 
Hi unclecharlie, as far as I know AutoCAD does not use any special system of math and does not actually have unlimited zoom. It's not particularly feasible to have unlimited zoom in any CAD program because there is a fundamental limit to accuracy based on how much memory is devoted to storing a number.

> Anybody able to explain in layman's terms what
> changed over the years?

What change are you talking about? Not much has changed in the basic geometry handling of AutoCAD...

You still have to use the regen command in AutoCAD, at least with AutoCAD 2008 which I just tested with. For example draw a small circle on the screen then zoom in to it, after zooming in you'll see the segmentation in the circle which will go away if you use the Regen command.

That's just how AutoCAD's display system is designed, it sets up a kind of static representation of the wireframe of the model and doesn't try to adapt the density of lines on the fly. Other programs like MoI which don't need a regen command are actually constantly recalculating the set of lines that make up a curve's visual representation at every screen redraw, that's what eliminates the need for a special regen command but if you go back to computers 30 years ago (where AutoCAD has its roots) they were a lot slower than they are now and it was hard to make things do dynamic calculations.

- Michael