topic Re: how to set up snap function in AutoCAD Forum

how to set up snap function

Anonymous — Fri, 21 Jul 2017 15:38:25 GMT

I want to set up the distance between my mouse arrow and the snap point I want to capture. If my mouse arrow fall within this distance, I could capture the point I want to snap. If not, nothing happens. sometime I capture an unwanted point far away. I want to avoid this senario. thanks.

Re: how to set up snap function

pendean — Fri, 21 Jul 2017 15:59:41 GMT

Could this be more of a "wrong running osnap getting selected" type issue?
How far is the point you want to select exactly from your crosshairs that one far away gets selected?

Re: how to set up snap function

Anonymous — Fri, 21 Jul 2017 17:07:08 GMT

SNAP or OSNAP, they are not the same.

APERTURE adjusts the size of the OSNAP selection frame

Re: how to set up snap function

GrantsPirate — Fri, 21 Jul 2017 17:27:36 GMT

If you have running Osnaps set then you will get the points on or off of geometry. With running Osnaps off and you explicitly use an Osnap, like ENDpoint, then if you aren't on geometry and pick you won't get the errant selection off of the geometry.

A more radical solution is to set your running Osnaps and set OSNAPOVERRIDE to 1 and only picks with an Osnap will work.

Re: how to set up snap function

Kent1Cooper — Fri, 21 Jul 2017 19:19:12 GMT

A caveat [be careful what you ask for]:

Osnap doesn't care whether the point you want to grab is within the APERTURE setting of the crosshair location, but rather whether any object that has any location on it appropriate to the current OSMODE setting passes through the "target" area defined by APERTURE, even if that location itself is not within the target. What you seem to be asking would prevent you from Osnapping to a bunch of things, such as the distant CENter of a large-radius Circle or Arc, or the MIDpoint of a lot of things [since you can't always easily tell where that is to get your target close enough to it, the way you can most ENDpoints], or many APParent intersections.

There can be many circumstances when it's desirable to Osnap to a location that's not very close to the cursor location, such as when there's a lot of clutter around the expected location but you can easily Osnap onto something more distant from there -- for instance, I just now wanted to snap PERpendicular to a floor-level line in an area with a lot of close parallel linework, and it would have required ZOOMing in quite close to make sure I got the right line in the middle of all that, but it was much simpler to catch it with the Osnap target way out past the end of the building elevation. I couldn't have done that in your scenario.

If it's even possible to come up with some code to check whether a potential Osnappable location is close enough, it seems to me you would have to have that code somehow running at all times in all commands at all locational prompts. I'm having a hard time imagining how that could even be implemented....