Drawing a texture onto an object at runtime

Hi there,
I’ve made a whiteboard to draw some stuff using render target. The pen uses line trace to draw, and the eraser uses a cube’s collision to draw polygons.
However when I set a material to be drawn with the eraser, it uses a simple color (even if I set a texture in the clear material). I want to apply a texture instead, in order to keep some of the previously drawn things (like a permanent pen).
Has someone any idea about how to draw a texture directly on a mesh during runtime, with the ability of writing on this texture ? (kinda specific question, huh)

With the actual setup, the eraser uses the color of the pixel found in the middle of the texture. I’m looking for a way to apply the texture following the uvmap of the mesh.

As a precision : the eraser gets its contact points with the whiteboard, and uses them through “Draw Material Triangles” node (target is Canvas). But as said before, it doesn’t draw material but instead a color used by the material. I think a step is missing where this material is mapped on the canvas depending on UV coords of the mesh it is applied to.

Any news here ? No idea ?