Hi Zlata! The input "P" from the "Tree Branch" component requires a "Data Path" (like {0;0} or {54;0;1} ). The output of the "Param Viewer" spits out exactly that. Try plugin in a panel to the output of the Param Viewer, to see this. Now the Tree Branch turned red because you're trying to input a culled list of "3d Points" (the output from the surface divide component), instead of a data path. I'm including an image I hope it's more clear. Good luck! Arie