Drawing on surfaces

 From:  Michael Gibson
1621.35 In reply to 1621.33 
Hi Steve, some other great news for v2 point picking / snapping stuff.

I have been able to make the improvements to snapping to not snap on to hidden points (like end / mid points) when the hidden line display is turned off.

You had mentioned this previously back here.

Here's an example - here is a model that has a bunch of hidden edges in the current viewpoint:

In v1 you can turn off the hidden edge display under Options / View / Display hidden-line edges, but all the endpoints and midpoints of those hidden edges would still remain snappable in drawing commands, like this:

With the new osnap visibility determination in v2, you will get these snap targets instead:

The visibility determination gets applied automatically when you turn off the hidden-line display.

There is also a new checkbox for toggling hidden line display under the View palette on the side pane so you can switch it on or off without needing to go to the Options dialog.

I think this is going to go together nicely with the new on-surface drawing stuff, it will help prevent excessive snapping on to the back side of the object and stuff like that.

The new treatment applies to End, Mid, Cen, and Quad snaps - previously in v1 Perp, Tan, Int, and On type snaps would actually be suppressed on non-displayed edges already.

A quick survey of a couple of CAD apps seems to indicate that this might be a pretty unique ability for MoI - doing a quick test of SketchUp, Rhino, and ViaCAD it appeared that none of those do this kind of visibility determination on things like end/mid snaps.

- Michael