When building elements are not aligned to the principal directions and an assembly is created from them, the assembly orientation is not as desired. This is readily seen when views of the assembly are automatically generated (a great time saver). Shown below are two pillars and a support that conform to such a case.
An assembly is created.
<LMC Elements><Modify><Create><Create Assembly>
Give it some descriptive name.
This assembly is now displayed in the project browser.
Create some views of the assembly
<RMC Assembly in Project Browser><Create Assembly Views…>
Here it is obvious the views were not generated orthogonally to the assembly and are for all practical purposes useless. Reorienting the assembly origin to the assembly geometry is necessary.
Note, if one is aware of the issue then one can reorient before generating the views (this will negate deleting the existing views)
<LMC Assembly><Modify|Assemblies><Assembly><Modify Assembly>
In the plan view, Move the origin onto a face tow which the origin gizmo can be aligned. Clicking and dragging on the blue corner allows one to move in the Red Green (XY) plane. The dashed blue line indicates an alignment to a face.
Dragging it onto a point allows translation.
A rotation aligns the axes to the geometry
Alternatively the planes of the gizmo may be aligned to geometry instead.
The plane that is aligned is both translated and rotated into position and one may optionally lock the alignment.
If one is practiced one may also perform these commands in 3D.
Finish editing the assembly.
<RMC + Shift Views in Project Browser><Delete>
Generate the required views. Note how the 3D Orthographic view is generated using the global coordinates and not those of the assembly!