How to realign two exact same meshes with different transform orientations?

Dear experts,
I am trying to find a way to realign two exact the same meshes in the same positions.

In the image attached you see a blue shape not being exactly aligned with the white shape. The pivot point was exactly the same, so I could use the copy location constraint. But because of an unparenting action or something else, I lost the same rotation orientation to use the copy rotation constraint.

Since I tried already so many things with the snapping tool, but I can not find the way to do it?
Your help is appreciated


It’s a bit ugly but you could shrinkwrap the second object onto the first object using ‘wrap method’ of nearest vertex.

You could try this way, if you can spot the same face on both the 2 objects (I hope I haven’t forgotten any step):

  • Select the object with which you want to align, select a face, create a custom orientation (Face 1 probably)

  • Select the second object, the one you want to align, go in Edit mode, select the same face, again make a custom orientation (Face 2)

  • Back in Object mode, enable the Options > Origins

  • In the header menu > Object > Transform > Align to Transform Orientations

  • Disable the Options > Origins

  • In the Transform Orientation panel, select Face 1

  • Again, in the header menu > Object > Transform > Align to Transform Orientations. The second object is now aligned with the first.

  • Select the first object, press shift S > Cursor to Selected.

  • Select the second object, press shift S > Selection to Cursor

Maybe i don’t follow, but if the origin is in the same place in both objects, couldn’t you…
Select both objects Ctrl-C and then “copy location” and then ctrl-c again and “copy rotation”.
The “copy attributes” add-on has to be enabled for the crtl-c menu.

You could try CloudCompare, if I recall it can perform “best fit” or point to point alignments. Since it appears you are using scan data it would probably work well ( it would not handle a object with UV coordinates and texture maps)

If the two objects are exactly the same with differrent materials, I would delete one of them and duplicate the other. After duplicating press esc to leave the duplicate in the same position, you will have two exact objects in the same position. Then asign one of the objects the other material.

Note that if you do this Blender will not know which object to render/display as they are totally overlapping, this means that it can erratically render parts of one or the other and you will get the same sort of result as you have before in your examples. It is possible that you have already managed to align them perfectly and what you are seeing is Blender not knowing which object to render/display.

Depending on what you are trying to achieve there are different solutions, what is your goal in having two exact objects in the same position?

My suggestion is similar to @moonboots solution, but automate with free addon keKit

if both have the same polygon

Dear @Photox, @moonboots, @APEC, @SidewaysUpJoe, @DNorman and @chrisd, all advises give me a good help; to shrinkwrap the blue object to the white object works out visually quite well for the purpose needed.

The two objects are part of an animation. I get confused when one of the objects again changes its object rotation orientation. In that way it is more simple to just copy one of the objects and delete the other, solved. But because they are both part of an animation I was hoping to find a way to just use the snapping tool in some way.

For a big project like this, with two identical human skeletons, but both transformed, I learn that local orientations change after un-parenting and it is difficult to merge them together again nicely in an animation.

Thank you for all your suggestions, that is very helpful