Align a planar surface to a

is there a command that will align a surface to e.g. the XZ plane ?

something simple like select surface, enter XY or ZY or XZ

enter angle of edge relative to an axis.

Secondly, if I have two or three planar surfaces all roughly parallel, I want to do a best fit for them to e.g XY plane, how is that done ?


If your surface is planar, select it then choose “Set CPlane to object” from the CPlanes toolbar. Do this in the perspective viewport. This will move the current CPlane to the Object. To remap the surface from this current CPlane to the XY CPlane, choose “Remap to CPlane” from the Transform toolbar and click once in the Top viewport. To reset your CPlane in the perspective view, activate that viewport and choose “Set CPlane World Top” or “Previous CPlane” from your CPlanes toolbar.


Try Orient3Pt

Select the objects to be oriented
Pick a point on the planar surface you want to be at the origin (or another point)
Pick a second point on the planar surface which is in the desired “X” direction from the first point
Pick a third point on the planar surface
Type “0” (zero) for the origin (or the coordinates of the desired location for the planes first point).
Type 1,0 as coordinates for second point
Click somewhere else on XZ plane.

The planar surface will be oriented on the XY plane.

Are you looking to get one “best fit” plane through all the selected surfaces and use that to orient all, or would you rather orient each plane individually?


I am looking for a best fit for all three surfaces, rather than adjust each one. They are but guidance surfaces within an object to best fit the object to the 3d world. Its an aircraft from photogrammetry and I have chosen a prt/stbd pair of frames, used divide to create a surface best fitting the points. repeated that on two more pairs of frames. Best fit should align the aircraft as best fit in that orientation, sorting it its heading, its nose up/down attitude and its tilt port/stbd.

I need the object where it is but just let it be adjusted slightly to get best fit.

it may also be that I use it to sort out the crazy angle its at.

I aslo have other uses.

I fear if I use orient3pt I am having to choose target points and it will move from where it is.

not sure how this gets used for two or more surfaces for best fit. I am not looking to do each surface, as explainmed, they are part of the aircraft and used to align better the aircraft.

Not sure how to choose a plane, eg 'click somewhere on XZ plane (not aeroplane !) as a target. what does one click on ?


Aligning planes up in space. I’ve some closed curves I want to reference to make other planar curves. I’d like to make sure the reference planes are exactly planar. Is the quickest method to create a cplane on one of the objects and project the others to that created plane or is there a tool that would select a number of planes and flatten them all to a ‘best fit’ kind of solution. There is one particular plane I’d like to true/flatten the other objects to. Can that be selected first or last to be used as the zero object?


Planes are always exactly planar. I’m not talking about surfaces or curves here, but actual planes - like CPlanes. Otherwise it is never safe to assume any curve or surface object is planar without checking - or if you really KNOW that it was created with a method that always makes planar objects and has not been accidentally modified since.

When getting an assumed planar object’s plane, beware of using CPlane>ToObject, because it also works on non-planar objects, so the reference plane you get will not necessarily be the one you want if the object is not really planar. The “safest” method of CPlane specification is 3Point with 3 known good points.

If you have a bunch of objects that you want to flatten to the same plane, the best is to do just as you proposed - set up the CPlane first and then project all the desired objects to it.

I have a few scripts in my library that “planarize” multiple surfaces or curves object by object - each with its own best fit plane - but none currently that average multiple objects. I can look into adapting them, but not today, probably tomorrow.

HTH, --Mitch

I see. The rub is that there’s planar and then planar to a cplane.

What would be useful I think is a means to ‘square up or true’ a selected plane to the current cplane without having to create another cplane or project to the current one. Does that make sense? Suppose I’ve a series of layout squares that are at different elevations and I want to be certain all are parallel to each other as well as the current cplane and If all the objects were selected and a command is called to make parallel or true or some appropriate description.

Well, here is something I wrote for the original poster in this thread (I think), it will align curves, surfaces or points to the nearest “best-fit” plane parallel to one of the principal world planes. It chooses the X, Y or Z plane automatically based on what’s closest. It does not do off-axis planes however. Maybe it can help you in some cases. As always with this type of autofix stuff, use with precaution…

–Mitch (2.9 KB)

Okay great, then as I understand it, one can select a single object such as a rectangle and this will flatten it in place relative to the current cplane?

The script will “flatten” one or more objects to the closest plane parallel to one of the principal planes. Each object selected will find its own plane independently. --Mitch