convex_hull.py

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import bpy
import bmesh

from sverchok.node_tree import SverchCustomTreeNode
from sverchok.data_structure import Vector_generate
from sverchok.utils.sv_bmesh_utils import pydata_from_bmesh

#
# Convex Hull
# by Linus Yng


def make_hull(vertices):
    if not vertices:
        return False

    bm = bmesh.new()
    bm_verts = [bm.verts.new(v) for v in vertices]
    bmesh.ops.convex_hull(bm, input=bm_verts, use_existing_faces=False)

    verts, _, faces = pydata_from_bmesh(bm)
    bm.clear()
    bm.free()
    return (verts, faces)


class SvConvexHullNode(SverchCustomTreeNode, bpy.types.Node):
    '''Create convex hull'''
    bl_idname = 'SvConvexHullNode'
    bl_label = 'Convex Hull'
    bl_icon = 'OUTLINER_OB_EMPTY'
    sv_icon = 'SV_CONVEX_HULL'

    replacement_nodes = [('SvConvexHullNodeMK2', None, None)]

    def sv_init(self, context):
        self.inputs.new('SvVerticesSocket', 'Vertices')

        self.outputs.new('SvVerticesSocket', 'Vertices')
        self.outputs.new('SvStringsSocket', 'Polygons')

    def draw_buttons(self, context, layout):
        pass

    def process(self):

        if self.inputs['Vertices'].is_linked:

            verts = Vector_generate(self.inputs['Vertices'].sv_get())
            verts_out = []
            polys_out = []

            for v_obj in verts:
                res = make_hull(v_obj)
                if not res:
                    return
                verts_out.append(res[0])
                polys_out.append(res[1])

            self.outputs['Vertices'].sv_set(verts_out)
            self.outputs['Polygons'].sv_set(polys_out)


def register():
    bpy.utils.register_class(SvConvexHullNode)


def unregister():
    bpy.utils.unregister_class(SvConvexHullNode)