Projection mapping

[Evgeni_Popov]

Maybe you can use the projection texture from the spot light to achieve what you want to do:

Babylon Projection Texture Support

The problem is with mipmapping, which is not full white at the lowest level(s) but grey. You can either create the mipmap chain yourself and make sure the lowest level is a white pixel or simply disable mipmapping for the shadow texture: https://playground.babylonjs.com/#CQNGRK#512