Pt 7: Smooth Ribbon Generation with Material Frames and Lofting in RhinoCommon

import Rhino.Geometry as rg
import ghpythonlib.treehelpers as th


num_branches = edges.BranchCount

num_sampling_segments = 100

ribbons = []

for i in range(num_branches):

    #iterate through all the branches

    edge_branch = edges.Branch(i)

    #join curves 

    curves = rg.Curve.JoinCurves(edge_branch)
    
    ribbons_per_family = []
    
    num_ribbons = len(curves)
    
    for j in range(num_ribbons):

        #extract the polyline curve and converte it into a polyline

        pl = curves[j].ToPolyline()

        #creatre a smooth version of the polyline

        crv = rg.Curve.CreateInterpolatedCurve(pl,3)

        # Smooth version. Extract different points and eval normals and tangencies

        t_params = crv.DivideByCount(num_sampling_segments, True)
        
        #create a list with the material frames

        cs_list = []
        frame_list = []
        for t in t_params:

            #create a test point

            p = crv.PointAt(t)

            #extract mesh point

            mp_pt = m.ClosestMeshPoint(p,0.0)

            #compute a normal

            p_normal = m.NormalAt(mp_pt)

            #extract the tangent

            p_tangent = crv.TangentAt(t)

            # Compute the cross product

            p_cross = rg.Vector3d.CrossProduct(p_normal, p_tangent)

            # Matrial Plane/Frame

            mat_frame = rg.Plane(p, p_cross, p_normal)

            #saving it into an empty list

            frame_list.append(mat_frame)

            # Create a rectangular section

            x_dom = rg.Interval(-0.5*width,0.5*width)
            y_dom = rg.Interval(-0.5*height,0.5*height)
            rec = rg.Rectangle3d(mat_frame, x_dom, y_dom).ToNurbsCurve()


            #Store the values

            cs_list.append(rec)

        brep_list = rg.Brep.CreateFromLoft(cs_list, rg.Point3d.Unset, rg.Point3d.Unset, rg.LoftType.Normal, True)

        for brep in brep_list:
            
            ribbons_per_family.append(brep)

        ribbons.append(ribbons_per_family)


ribbons_tree = th.list_to_tree(ribbons)

#OUTPUT

Ribbons = ribbons_tree