How to test this drawing: create and edit a curve and press shift + drag your mouse (or tablet). The Curve needs a Bevel Depth > 0.0.
Note: The ideal solution would be to use a different shader, that takes
no lighting. However according to Clément Foucault there is an assert preventing the same batch to
me used with different attributes (or something like that). Il wait
until the end of such resolution before revisiting this. That said, it
is working fine.
Part of T49043
Differential Revision: https://developer.blender.org/D2501
d4e9c27e4e