Rotate about about reference line


I am trying to rotate a part of a sketch to align with another part using the rotate and rotate 3D tools. I am not able to define a reference plane to use for the rotation of the sketch to allow me to rotate it to where I need it to go. From using CAD I am used to setting a reference axis and then performing the rotation but rhino does not work that way… Can anyone help?


Rotate 3D works with a reference axis, defined with 2 points for example. Does this achieve what you are looking for ?

Sadly, no. The only way I could do what I needed was to draw lines from the 2 connection points of the 2 sketches back to the rotation point in an orthogonal view, then measure the angle and then go back and do the rotation from there. A real hassle…

So you would like to use… a construction plane and a point?

I’m not sure I follow you, sorry.

Sorry - it’s a little late here - typing while sleepy :wink:
What exactly would you like to do? You mention both a plane and an axis in your original post so it is not clear to me what reference objects / clicks you want to use…?

Could you post a model showing the object to be rotated, the target and what the matching points are? My tiny brain works better when I can play with the problem.

If you don’t want to reveal intellectual property, swap in some cubes oriented like the parts.


Pre-empting a model, Orient3d could be what you are looking for…

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Hi, I have include some images of the profile I am working with. It is an existing profile that I am trying to make smaller. I need to rotate about the bottom point of the selection and align the top point with the straight portion next to it. Rotate functions just don’t seem to be able to do it…

You could set the CPlane perpendicular to the curve CPlane and select Curve option, then select curve and where on the curve you want to rotate about. Then use Rotate command. (This is equivalent to creating a temporary line tangent to the curve, and then using Rotate3D with the curve as the rotation axis.)

Can you post a .3dm file with the two curves? Click on the vertical arrow above where you type your posts. A file would make it easier for someone to understand what you are trying to do and how to do it.

Rotate will do that just fine if you put your C-plane in the right place, that is if you want to have bad geometry, as it won’t be tangent or continuous. My point is that’s the incorrect way to solve the problem you have there. you really need to extend the lower line the same amount as the gap created at the top. and in the same plane, so that then you can translate that curve to the new endpoint, keeping your curve continuous and tangent.

Here is a copy of the file. Evan, thanks for your comment. I understand what you are saying and I agree with you. That opens up a whole new problem that I don’t know how to fix…

sketch profile.3dm (141.2 KB)

Hi Michael - I think maybe the cyan arc is the one you want?
sketch profile_Maybe.3dm (37.1 KB)


Thanks Pascal. Yes that achieves the rotation but going back to Evan’s comment, I see now that I need to maintain the original orientation, move it over to connect with the rest of the sketch, and somehow redo the arcs and tangencies. I’m still learning…