Draw to texture

Hello everyone.

Basic WPF 3D allows to draw to texture in runtime, using RenderTargetBitmap in material. So, drawing in this bitmap instantly affects on mesh texture.
In Helix Toolkit the visible texture changes only after re-attaching model, or using AttachMaterial() in MaterialGeometryModel3D. But these actions finally use something like this "...DiffuseMap.ToByteArray()", and it totally wastes speed of execution;


Is there some way to overcome this and/or bind Bitmap (or it's pure byte[]) to DiffuseMap?
Or Helix Toolkit have fast method to chenge texture?
Thanks!