Align object by 1 face normal to world axis

Technical Support Geometry Nodes
1

I have an object that is a single face that is frozen in a randomly rotated position that does not align with any world axis.

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I have managed to find the face normal vector and position a mesh line primitive to visualize the face normal.

I need to now calculate the difference between the face normal and world Z so I can rotate the face so its normal points up in world z and then I want to instance the object on points created by Distribute Points On Faces on another object.

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test align normal to world axis.blend (134.3 KB)

solution part 2: Align object by 1 face normal to world axis - #4 by stray

2

Align Rotation should return the rotation to selected Object axis if you just plug Vector into it :thinking:
Like so:

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3

I can’t figure out how to make it apply to a collection of objects.

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The plan was to use geometry nodes to straighten out all of the source objects and then instance them on points on the sphere.

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It works when there is only 1 object in the source include collection, but as I add more objects to the source, the rotation fix doesn’t get applied to them. How to fix the rotation on each thing in the collection instead of needing to put a Geometry Node modifier on each individual object?

test align normal to world axis.blend (140.7 KB)

4

You can try:
Input Instance in For Each node > set For Each: Instance > Realize Instances > rotate the face (apply you “align” node group) > Geometry to Instance > go to “For Each” exit.
The lower “For Each” geometry output should contain a collection of rotated instances, that you should be able to use as usual in Instance on Point.

5

Thanks

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test align normal to world axis.blend (144.7 KB)