OrientOnCrv - options Flip/Rotate missing?

The help file describes the options Xflip/Yflip and Rotate for OrientOnCrv. I don’t see those appearing when I type the command or choose it from the “Transform” menu.
When I use the tool button I do see those options to click on, however the orientation of the object respective to the curve is different, and not as described in the help file.

Base point for the original object is 0,0,0.

About the help file text: following the video example, “Pick an angle or two reference points to rotate the curve.” should read “Pick an angle or two reference points to rotate the object around the curve.”

@Heimo_Mooslechner: this should be a good command to use for creating your geodesic structure member crosssections (after McNeel has solved this bug). The Rotate option can be used to orient the section towards 0,0,0.

This seems to be easier, because the cuts on the Knots are made automaticly:

OffsetSrf - but You have to make some linear constructions before to get the right angles… Ill make a Vid…later

Will be to seen - here:

@Heimo_Mooslechner: I would appreciate it if you continue to describe your exploits in your original thread, I promise to read them over there. I would like to keep this thread about the bug that I think I found, I only referenced your name because i thought that this command could be useful to you, but at the same time I wanted you to be aware of the current problem with it.


Hi Max - that only appears if you have set the Perpendicular option.


Not so, Pascal. I’ll describe it in more detail:
I create a surface object, centered around the world origin, in the Y-Z plane
I type the command OrientOnCrv (so I do NOT use the tool button)
Rhino request the base point, I select the world origin
Rhino requests to select the orientation curve, I pick a curve
Rhino requests a new base point on the curve, I do NOT click on the “Perpendicular” button, I pick a point on the curve.
The object is placed around the curve as I showed with the lower example in the picture, no possibility to flip or rotate the object.

Interestingly, when I DO click on the Perpendicular button, the options flip and rotate appear, but the object orientates as per the upper example, so the same as when I use the tool button. I guess I could work with that when I orient the original object in the X-Y plane, but the point is that all this is not as the help file explains it. And I think the behavior should be the same irrespective what method one uses to generate the command, typing, menu or tool button.


Yep, the plane used for orienting is not the plane of the object, it is the plane that is active when you pick the base point. Does that make sense with what you see? It can definitely be confusing, and I’ve chatted with the developer about using the plane of planar objects to orient - it would usually, I think, make more sense.


I agree, but it should be consistent irrespective the command method used.
I had another look at the help file, and I noticed it is ambiguous too. The first picture shows the X-axis of the original object being re-oriented along the curve, but the vid’s describing the options Flip and Rotate show the blue Z-axis oriented along the curve. I think some alignment (pun :wink:) is in order.


Once Perpendicular is set (and Flip options become available) then the reference plane is set perpendicular to the curve, and the Z axis of the plane is tangent to the curve; otherwise the X axis is tangent to the curve. Does that make sense?


No, not really. I think Rotate (around the curve) should always be an option irrespective of the Perpendicular option. I am not sure about Flip though.
And the way it is now, the tool button does not even give you the choice, it always orients the object Z-axis tangent to the curve. and there is no way to undo that.

So, the perpendicular plane would be the plane of rotation, correct? A plane perp to the curve at the location of the base point as mapped to the curve? I could see that being handy…




Pascal, I feel I should reiterate my original comments. Yes, it would be nice if rotating around the curve was available without having to select the Perpendicular option first, but you can easily work around that by orienting your original object properly. But my complaints were:

  • the help file text is ambiguous, or at least the requirement to select the Perpendicular option first before you can Flip or Rotate is missing. Also, in my opinion it would have been much clearer if the same object had been chosen to demonstrate the options.
  • The tool button seems to incorporate the Perpendicular option from the start (without any possibility to undo this option), while the same command when typed or generated from the “Transform” menu does show the Perpendicular option.


Thanks - Sorry! - Your thought arrived here!