Yeah, Franck it works, it gets rid of the artifacts alright, but if you look closer at the branches, the mapping isn't right with the world parametric coordinates, so it's a workaround, but not the ideal solution, I'm afraid. I've been trying to remap only the base subset of the plumtree to world parametric, while keeping the trunk subset to object standard to keep the mapping correct on the branches ( same subsetas the trunk), but it doesn't work, I still have only 2 materials for the tree in the mat. summary, and it's the trunk and leaves materials, Vue doesn't generate a 3rd material. Seems like a bug to me.