V6 One shot object snaps broken?

…or maybe they have to be set in options?
Anyway, they arn’t working here.


Hm, seems to work here, either from the Object snaps toolbar or using SHIFT+LMB from the OSnap dialog. Is there a specific snap which you see not working ?


The center one shot specifically - when I posted I had pasted some stuff I was working on in v5 over to v6 - in v5 everything worked fine, in v6 on exactly the same geometry it wouldn’t work…

ok - what it is is that the center object snap wont snap to certain entities that it will in V5.
I attach the V6 file, where i have marked the edges.
no object snap.3dm (472.9 KB)

Hi Tony- thanks, I see that.



Hi Tony- these arcs count as ‘approximate’ and not exact arcs. In V6, Cen does not see approximate arcs by default, this has to be enabled in Options > Modeling aids,


Hi Pascal,

thats odd indeed as the surfaces by rabbit making up the hole do have proper circular weights. I don`t see what has been approximated here ?


Hi pascal
Ok, I see by following the tracking link what the thinking is behind this.
But, isn’t this a part of a bigger issue as to how to deal with geometry in a model that is not in tolerance?
Like how was I able to make those out-of-tolerance arcs in the first place?
In fact, the holes were made with the MakeHole command - so does this mean we cant rely on MakeHole?
Some of those holes are fine, some arn’t - why?
How would I know when making a model if the arc, circles were ok if I hadn’t tried to centre-snap to them?

I welcome anything in built into rhino that will check and or analyse geometry, but overall don’t that set of tools need to be wrapped up in an interface where it is plain to the user what is going on?
Also, I may well decide to turn off that “checking engine” if I was designing things that were not going to be made in the real world, or if the tolerances of the parts to be made didnt need to be that exact.
In my case if the end result was to be built by carpenters and by hand as opposed to being sent out to be cut and/or folded by machine.

Are there other things new in v6 that relate to this kind of tolerance checking…?


Right, it seems odd to me- they do not simplify (simplifyCrv) to circles either though they are within 2.64686e-007 of a circle, which seems close enough. There is a bug on the pile for this part, I think.


However… in looking at one of these non-circles a little more closely and comparing its points to those of a Circle aligned the same way: seven of the eight points are ‘duplicates’ but in fact they are ever so slightly not the same.

ON_Point: (-1137.0922075735762, 941.41501302465667, 114.15229405755534)
ON_Point: (-1137.0922075735766, 941.41501171472851, 114.15229483811154)

I’ll see what I can find out about this…