OSnap project not as expected

There is an object below/above the cplane.
I want to move it to Z0 without changing XY.

When _Move asks for the start, I select a point.
Then I activate Project in the OSnaps and go to the same point.

No projection happens.
I think it should.

I now see in V8 it’s fine.
Should be in V7 as well.

(I know about _ProjectToCPlane etc.)

Hi Charles - this depends on whether Planar is active in the status bar. If Planar is on, then there is a ‘virtual’ CPlane passing through the last selected point and Project goes to that plane.


I think Project is defeating you.
With Project turned on with Center, when you put your mouse over the circle, Center finds the center, and project drops it to CPlane zero.

For a Move you would need to start Move and grab the center of the Circle with Project turned off. That’s the point you’re moving from.
Then turn on Project and click the circle again. With Project on for the 2nd pick, the circle center is moved to CPlane Zero.

There is a logic, but not for the user…

Exactly what I did.
Planar fights against it with no reason except internal logic.

Not really - this is what Planar is for - you can snap osnaps coplanar with the previous point.


Another story, often asked in trainings:
Why do I need to touch the circle, why can’t I simply go to the center?
While I can imagine the reason, the question is a good one.
It is possible:

Ok, you won!

Because there is no object at the center of the circle to evaluate.
The object is the circular curve and it has a center.

This is the “peephole” Rhino is looking through to find an object:

That’s exactly my answer.
I say ‘How do you grab a hoola hoop ring from the floor? Do you grab it in it’s center?’.
Nevertheless the center snap could be smarter.
Why not search the visible area for centers and let the one win where the mouse is?
This approach could be restricted to arcs and circles.
For closed polylines it could be confusing.

I suspect the unintended consequences of that sort of change would be extraordinarily disruptive.

Every tool requires a little technique to use it efficiently and effectively.

Hi Charles - I guess the advantage here is that you can specify what center to look for - if there are multiple objects with centers near each other, searching in the center is going to be harder than finding the curve you care about at the curve itself.


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We don’t know because we can’t play with such.

You are completely right.
I myself understand it and I know how to use the center snap for decades.

Sometimes customers have good ideas.
That’s why I mentioned the “issue”.

I agree.
As you can see in the video, both methods can work.
If you touch an arc/circle, that’s the first priority.

But overall it’s not that important.
I only wanted to report customers thoughts.

Thanks for airing your ideas. They are helpful.
Sometimes the ideas we hear are great and we try to add them.

I didn’t mean me when I said ‘customers’…

Thanks @John and @pascal.