Wish: Gumball Arc SmartTrack Snap improvement?

Gumball arc should snap better to SmartTrack when rotating an object. For example when rotating a single line from any planar orientation to be parallel to a coordinate axis, I can’t get the Gumball to snap. It is not a problem with the Rotate command.

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Hm… hard to win that one. The gumball can be aligned to object so it snaps to its own ortho with snappy dragging, or it can be aligned to CPlane and it will not line up with your line but it will see the Cplane ortho…


Can you fix this?

Hi Martin - I may need another coffee but so far I am not clear on what a fix would be.
If gumball is set to by object, currently, it aligns to your line. If you use snappy dragging and ortho, you can rotate the line 90 degrees (or ortho angle) but you cannot rotate to an ortho on the CPlane. If it worked on the CPlane, then the current behavior would be lost, and, furthermore if the line were skewed in space, the behavior would make no sense…


As I wrote already, I can do everything with the Gumball except rotate a line from a random orientation to an orthogonal orientation with a fixed pivot point. It’s easy to orient the line when the position can change but when you simply want to rotate the line around either start or endpoint and make it parallel to a coordinate system axis, that doesn’t work right now.

Would it be possible that the Gumball snaps to C-Plane ortho while rotating?

I know it aligns to C-Plane ortho for alignment…

This is still a problem. In Rhino 8 WIP, I see these little white lines and the gumball could snap to those couldn’t it? SmartTrack also still does not create a snap along the CPlane axis…

@pascal this is still a problem. Unless another line is present which SmartTrack can use as parallel guide, SmartTrack does not create a horizontal guide.

Dragging a gumball arrow allows snapping to a CPlane axis.

Relocating the gumball or reorienting it by double clicking on the arc, it does not snap to the CPlane axis.

Isn’t this possible?

Hi Martin - I thnk it will do what you want if snappy dragging is set.


I have snappy dragging on all the time and it doesn’t snap to the origin and axis.

yeah… I see - it works once but not twice, hitting the SmartTrack axes during relocate/rotate

It looks like Ortho works relative to the CPlane if you rotate with the gumball, and relative to the gumball if you relocate/rotate…


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SmartTrack should work both relative to the gumball and the CPlane.

Hi Martin - how do you envision this working? How would one distinguish ?


As soon as a horizontal line is present, the gumball smarttrack snap can be used to find a perp point. Maybe we need smart axis instead of smart origin?

Hi Martin - bear with me if I am not quite getting what you need to do - one coffee only, so far - but… resetting the gumball will re-align to the CPlane… is that not what you are shooting for here?


I want to be able to do this without the need of a helper line but instead I should get a horizontal SmartTrack guide by hovering the cursor on the CPlane origin.

I’m also drinking a lot of coffee :grin:

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I think the goal is to able to snap the object to the OnOrtho line that is available when using Rotate ?
Adding a smart track point to the origin of the gumball could be useful also…

And I do see that when using Rotate (or Move or Orient) the object before rotating is “snapable”.
So, why isn’t that the case in OrientOnCrv ? :sweat_smile:

How do you get that smart track point on the CPlane origin to get active ?
→ Smart Point at CPlane origin, found it.

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Yes. It creates a point but what I need is an axis.

I guess for now I just put a block with grid axes in my relevant files.