Rotate object such that one of its pivot axes is collinear with an edge

[ReignOfError]

I have a dummy object and a mesh. Using midpoint snapping, I've moved the dummy such that its pivot point is coincident with the midpoint of an edge on the mesh. I'd now like to rotate the dummy such that one of its pivot axes is collinear with the edge.

Here's a screenshot of the situation (the edge I'd like to align the dummy with is circled).

Essentially, all I want to do is rotate the dummy object such that either its x or y axis lies along the edge.

I've checked the documentation for the align tool and it appears that it's only possible to align a sub-object to an object, not the other way around (as in this case). I haven't found anything helpful on the internet, either.

Any suggestions or comments regarding how I might accomplish this would be much appreciated!

[ReignOfError]

I found a rather circuitous method of doing this using Chris Whitaker's FB Sub-Obj Pivot script:

- Select the edge (I did so within the Edit Poly modifier).

- Run FB_SubobjPivot (installation instructions are provided in the comments at the start of the script file).

- The working pivot should now be aligned to the edge and active.

- Select the dummy.

- Activate the Rotate tool.

- In the Absolute Mode Transform Type-In, change the appropriate angle to 0.

Side note: The comments for FB_SubobjPivot claim that it can also align an object's pivot point (instead of the working pivot) to a sub-object. This would allow for slightly simpler alignment of the dummy to the object containing the target edge through use of the Align tool. Unfortunately, I couldn't figure out how to have a sub-object selected while in "Affect Pivot Only" mode (which is what I assume the "if in 'Edit Pivot' mode it'll modify the object's pivot" comment within the script means).

Anyway, this works, but it relies on a third-party script and is rather cumbersome, so if anyone knows of an alternate method, please let me know!

[PROH · Accepted solution]

Hi. I would do it another way.
1) Activate "Actice Grid" a create the dummy by dragging the mouse directly on the surface the dummy should be aligned with.
2) The dummy is now aligned with the surface, and all you need to do is to snap the pivot to middle of the edge.

Hope it helps

[ReignOfError]

Thanks for the suggestion, PROH. In this, case creating the dummy object on a surface that intersects the edge using AutoGrid works well (and it's faster than the method I found). Just for future reference, here's two screenshots:

However, this method isn't universally applicable. For example, if the vertical surface I used in this case wasn't present, I couldn't use the horizontal surface (since the target edge isn't along one of the axes AutoGrid uses for that surface):

Such a case would (as far as I can tell) still require the use of the FB Sub-Obj Pivot script.

Regardless, I think in most cases it wouldn't be too difficult to find a convenient surface, so in the future I'll certainly try to use this method before resorting to the script.

[PROH]

Hi. Glad it helped. In those cases (rare) cases where there isn't a usable surface, you can easily make one by either extruding the edge or by creating a shape from the edge and then extrude the shape. These are just a few of many options.

Hope it helps