The line was made with two major steps: We create a mesh in runtime using the cross product between the direction the crayon is moving and the UP vector. This way we have a side vector that can be multiplied by the desired thickness and used to create the mesh.
On the rendering side, the trick was to use the x coordinate of the UV multiplied by a noise with blend mode as multiply. This way we can have the "photoreal" effect on overlapping strokes
