Fix for edge width artifact caused by the perspective

[filipinascimento]

A fix is needed for rendering edges.

As shown in the image, if the position of start and end are similar relative to the camera Right and Up vectors (XY on the view coordinates), it reduces the edge width depending on the angle of view. This is caused by the perspective transformation that happens after projection as objects with similar positions in XY in the view coordinates can still be placed in different positions after perspective correction.

Currently, the viewMatrix is being multiplied to the displacement vector to be written in camera right and up coordinates (see Shaders/edges.js )

I'm not sure how to fix that without doing all the perspective calculations in the shader.

[filipinascimento]

Maybe using corrected perspective inverse transformation:

https://towardsdatascience.com/inverse-projection-transformation-c866ccedef1c
or this:
https://math.stackexchange.com/questions/1691895/inverse-of-perspective-matrix