A simple perspective toolkit for Blender Grease Pencil.

These have various customizations and features documented below.

Questions? Concerns? Please reach out!

"Clicky" Mode. You can now drag and drop vanishing points (represented by empties) rather than using numerical coordinates. Make sure your blender viewport is in Object mode.
Randomization option

Here are a couple time lapse sketches to get a sense of how this works (no audio).

The first video below will show how to setup the tool for usage. The second shows a quick sketch made using the tool

Notes:

To move the vanishing points in Clicky mode, you must be in object mode (2D Animation defaults to Draw mode).
To see the Perspective Assists, you must have a Grease Pencil object selected (Normally you will select the Grease Pencil object you are drawing on, and switch to draw mode.)

Release Notes

What's New 1.1.3

What's New in 1.1.2

Vertical and Horizontal Rulers while using the Perspective Assists (can be toggled while drawing)
Various grid generation improvements to allow for cleaner grids
Bug fixes

What's down the road:

Using Perspective Assists with manual rotation of Grease Pencil objects is not supported at this time (Scale + Move works fine)
While archived grids can be used as reference, they cannot be used with Perspective Assists (This will be fixed in a later release)
For the Three Point perspective grid, some unexpected behavior may occur If multiple VPs and the Obs Pos have the same X and/or Y values. Tweak values slightly to avoid issues.