If what you want is to change continuously the pivot for modelling complex models go directly to
https://www.youtube.com/watch?v=rIh7LvjthZY&t=595s
This used a custom grid to change around the coordinates system for irregular models. This system is way too much or inadequate for casual and other uses. For that use:
Using main pivot
There is a “working pivot” mode that will allow you to do changes in a temp pivot without affecting the main one. This is a ref using the main pivot.
Activate pivot mode
Activate editing pivot using “insert” key (you leave in the same way). You are already in pivot editing mode, but you won’t see the gizmo until you select, or deselect and select the object or start to transform. This doesn’t affect the functionality.
Align options
In this point you can use any align tool from Max including in the tool bar:
- Transformations

- Snaps

- Select and place

- This is Ok to place it in any point of the surface,
- Selecting a face it will align X and Y to the face. Z will aling with the main normal of the face.
- With snaps verts will snap it to verts. But only a single one, meaning you can not use two verts to aling precisely in one direction X and Y, you need scripts for that. Sometimes this is key.
- It has a mode to allow you rotate along the normals free mode.
- Align tool.

- This is mostly to align it to general aspect of the object. But there are scripts that can be quicker to use.
Using scripts
If what you want is also control the location of the pivot but also align the pivot in a precise way, for example align it to two verts, then you need to use scripts. This is for example one, that manage also entering and leaving pivot mode.
3 points align
There are other scripts to manage position of the script in amore general way, for example as align tool would do but in a lot quicker way.
Generic pivot controls
Notice that in the pivot panel control you have tools to control the pivots. Going each single time to this panel can be slow and it is better relying in quicker methods when a work needs frequent use of pivots.
