Entity become not parallel to UCS after 3D align. How to make it parallel again?

Hello.

When 3D align used on an entity (3 point align, for example to mirror an entity), it become not parallel to UCS (even if z stays at 0).

How do I make that entity parallel to UCS without changing UCS view?

Thank you.

When you mirrored the 3D entity did you establish a new origin?

I don't know what that means, so I guess I didn't.

I just run the align command and select 3 points. The mirror was just an example, because using align saves a lot of clicking instead of run mirror command then align with 2 points.

I do however use align for turning an entity from 3d position to 2d (like flat sided pyramid).

Attach a copy of the drawing to your next post. An image won't do. Maybe someone here can take a look at it and suggest a fix. I've got to hit the road but I'll check back later.

There you go. It's a simple 3d "pyramid" made with regular lines and polylines. On the right are "flattened" parts of the pyramid via align command, all with 0 z coordinates, they are no parallel to UCS, even though the original pyramid was created by moving small square by changing z coordinate and then using line command joined corners of both squares. UCS was not changed at any time of creating the drawing.

[EDIT]

I just discovered, that on regular lines I can use command flatten. On polylines I guess I could combine explode -> flatten -> pljoin

align-example.dwg

The pyramid is more like 2.5D not 3D.

I'd suggest doing this drawing as a true 3D solid then using either SolProf or the combination of SolDraw/SolView to extract the 2D views.

This was just an example. I don't work with 3D solids. The only 3D I get are some 3d polys from our measuring machine. Or if I have to draw simple objects with lines and then unfold them into 2d space (just like the pyramid in the example).

You can relocate,realign, and/or reorient the UCS to whatever you need which might be the best option. are you using the mirror command or mirror 3d command?

Another option might be to use the "3darray" command and enter the parameters to rotate the new/arrayed object so it is perfectly mirrored with the UCS and the original.

-ChriS

I am interested in understanding why this happening and how to "fix" the result, rather then looking for alternatives or work around.

You seem to be referring to the vertical (Z) alignment of the top square in your model with relation to the bottom square, Correct?

Since you are dealing with 3d linework only, I would recommend using 3dpolylines throughout. That might even solve your problem (not sure).

I should note that you can snap to and align with the midpoint of your lines but I don't think midpoint snap is on by default. You have to enable that in the snap settings.

That could be part of the problem here?

-ChriS