OSNAP Project issue

Hi Rhino forum,

I have a small problem that is hopefully just caused by my ignorance on the OSNAP functions. If anyone could share their knowledge or if they experience the same issue, that’d be greatly appreciated!
As I turn on [Project] in Osnap, my understanding is that your command would now be limited to the construction plane of the viewport you’re working in, ie. When in [top], construction is in X/Y direction, [front] construction would be in X/Z direction. This has been true for me for as long as I used Rhino.
Recently I’ve been occasionally experiencing an issue that when I’m in [Front] view, I’m unable to move in the Z direction. I have then turned on and off Osnap-project, toggle mode back and forth from CPlane to World, with no success. As this happens my [right] view would stay normal and I can move in the Z direction. However I’m not be able to reliably reproduce this issue, it just occasionally comes up but is very annoying when it does.
Would anyone have an idea on how I could approach fixing this? Am I just missing an Osnap checkbox that I should know of?

Thank you so much,

My Rhino version is Version 7 SR6.
(7.6.21127.19001, 2021-05-07)

The Project tool in OSNAP always means when I select an endpoint/midpoint/etc. that is not on the CPlane in the current viewport, that point will be projected to the CPlane using the normal direction (shortest) to the CPlane.

The white witness line shows you where it will be projected to before you click.

You’ll need to look in the Perspective viewport to see the projection.

Hi John - Thanks for the response. I think I understand and used to correctly experience what you’re describing. For example, if in [front] I want to move a geometry at ref pt[1,1,1] to [1,1,5], I should be able to turn on project and move it by turning on Osnap and move my geometry in the Z axis, without worry that the x-coordinate of my geometry would change. Is that correct?
What I’m experiencing is that when I work in [front], my cursor is occasionally “bound” to z[0] and I’m unable to move it up/down at all through snapping. (I can still use gumball to move) I’m unable to scale1d in the Z direction or use similar comments that require me to snap to anything that’s not on z[0].
Is there a way to examine this?
Thank you,

That is the expected behavior with OSnaps projected. The Z component of the snap location is ignored.


Thank you for the clarification, Pascal!