# Change object orientation to be parallel with the orientation of a normal of plane [duplicate]

So I have an Object that is orientated in the World like this:

Even dough, the object is located and rotated with 0 values in all axes, the planar part (bottom / not round) of the mesh is not align with the X axis like intended.

I have already changed the origin, to the place that I want using the "Set Origin".

But what I really need is to change the orientation of the mesh, and I don't know how.

This probably happened because of some transformations that where made in the Mesh or something like that. So here the Mesh is rotated and not the Object, and I need this the other way around, the Object rotated and not the Mesh. So the orientation of the object and the orientation of normal of the planar parte of the Mesh precisely parallel, and not changing the form of course.

So, how do you do this?

What is the proper way to handle things like this?

Thanks for any help in advance.

• One way: Rotate in object mode about z axis such that it is aligned. Copy the z rotation value. Apply rotation (ctrl - A). Then paste in rot and negate. Jan 31 '18 at 15:21
• Thanks @batFINGER! The problem is that it will not be precisely parallel, it could be close, but is not the same. So this is absolutely necessary! Lets face, for computers this should be easy like copying the rotation of the normals of one plane in the Mesh to paste in the rotation of the object, or something like that. Shouldn't it be? Is it possible with Blender? Jan 31 '18 at 15:34
• Simplest way is first one shown in the linked answer, adding dummy object, snapping it to surface of what to align, parenting and resetting rotation of dummy object Jan 31 '18 at 15:52
• it looks to me like it's out by (90 / 8) degrees about the old origin. Could use snap tools in UI, or use some vector math to get the angle. Put the cursor on radial vert and use its x, y, z to find angle (in radians) from the x axis angle = Vector((1, 0, 0)).angle(Vector((x, y, z)) (oops had z axis not x axis reposted) Jan 31 '18 at 15:58
• So I guess it is not possible at the moment with blender in a simple way @MrZak, and this like that question that can give some ideias, not not with out some work. Since it passed 3 years almost… Thanks anyway! Jan 31 '18 at 16:22