_OrientOnCrv unexpected base point

2023-09-22_OrientOnCrv.3dm (30.2 KB)

I want to copy the red curve in the same direction as the original red curve on the cyan curve.

Therefore I _OrientOnCrv.

I select the red curve.
Then I set the base point to the upper end of the red curve.
Then I select the cyan orientation curve.

The copies go to the outside of the cyan curve.
Flip doesn’t change it.

Ok, then I invert the direction of the red curve.
No change when using _OrientOnCrv.

Finally, to get the desired result, I have set the base point to the lower end of the red curve.
Then it works ok.

Is there a misunderstanding on my part regarding the base point?

This is confusing… Also the perpendicular option…

If you use the option Base point OnCurve it works as expected.

Yes, strange, I already selected the base point…
…I think something is not quite right.

I tested in V5-8, it works always the same (Flip option is not there in V5).
So my first idea was that it is my misunderstanding.

Any clarification, perhaps @Gijs or @pascal or so?

Hi Charles - yeah, It is confusing and not always very intuitive - the problem is, the orientation plane uses the current Cplane as a reference - in this case, if you flip the front CPlane so that Y is down, it does what you expect. I agree this could/should be better, I’ll see what we can do. My guess is a fix would entail more user input, more like OrientOnSrf, to establish a base plane since the object to be oriented is not necessarily oriented ‘correctly’ to begin with - it can be anywhere.

ArrayCrv does ‘the right thing’ here… so it should be perfectly possible.


Thanks for the explanation.
Once understood, the behavior makes more sense.

Good to know it’s not just my stupidity :wink: