Add new PolygonSort node to sort polygons by distance, area, and normal angle

9992a5bb · DolphinDream · f5424a4c · 9992a5bb · 9992a5bb · 9992a5bb
--- a/docs/nodes/list_mutators/polygon_sort.rst
+++ b/docs/nodes/list_mutators/polygon_sort.rst
+Polygon Sort
+============
+
+Functionality
+-------------
+
+Polygon Sort node sorts the input polygons by various criteria: distance, area and normal angle.
+
+Inputs
+------
+
+All parameters except **Mode** and **Descending** are vectorized and can take single of multiple input values.
+
+Parameters
+----------
+
+All parameters except **Mode** and **Descending** can be given by the node or an external input.
+
+----------------+-----------+-----------+--------------------------------------------------------+
+| Param          | Type      | Default   | Description                                            |
+================+===========+===========+========================================================+
+| **Mode**       | Enum      | "D"       | The sorting direction mode:                            |
+|                |           |           |  P  : Sort by the the distance to a point P            |
+|                |           |           |  D  : Sort by the projection along a direction D       |
+|                |           |           |  A  : Sort by the area of the polygons                 |
+|                |           |           |  NP : Sort by the normal angle relative to point P     |
+|                |           |           |  ND : Sort by the normal angle relative to direction D |
+----------------+-----------+-----------+--------------------------------------------------------+
+| **Descending** | Bool      | False     | Sort the polygons in the descending order.             |
+----------------+-----------+-----------+--------------------------------------------------------+
+| **Verts**      | Vector    | none      | The vertices of the input mesh to be sorted.           |
+----------------+-----------+-----------+--------------------------------------------------------+
+| **Polys**      | Polygon   | none      | The polygons of the input mesh to be sorted.           |
+----------------+-----------+-----------+--------------------------------------------------------+
+| **Point P**    | Vector    | (1,0,0)   | The reference vector: Point P. [1]                     |
+----------------+-----------+-----------+--------------------------------------------------------+
+| **Direction**  | Vector    | (1,0,0)   | The reference vector: Direction D. [1]                 |
+----------------+-----------+-----------+--------------------------------------------------------+
+
+Notes:
+[1] : "Point P" is shown in P and NP mode and "Direction" is shown in D and ND mode. These are used for distance and normal angle calculation. The area mode (A) does not use the input sorting vector.
+
+Outputs
+-------
+
+**Indices**
+The indices of the sorted polygons.
+
+**Vertices**
+The input vertices.
+
+**Polygons**
+The sorted polygons.
+
+**Quantities**
+The quantity by which the polygons are sorted. Depending on the selected mode the output quantities are either Distances, Projections, Angles or Areas.
+
+Note: The output will be generated when the output sockets are connected.
+
+Modes
+-----
+The modes corespond to different sorting criteria and each one has a quanitity by which the polygons are sorted.
+* P : In this mode the polygons are sorted by the distance from the center of each polygon to the given point P.
+* D : In this mode the polygons are sorted by the projection component of polygon center vector along the given direction D.
+* A : In this mode the polygons are sorted by the area of the polygons.
+* ND : In this mode the polygons are sorted by the angle between the polygon normal and the given direction vector D.
+* NP : In this mode the polygons are sorted by the angle between the polygon normal and the vector pointing form the center of the polygon to the given point P.
+
+Presets
+-------
+The node provides a set of predefined sort directions: along X, Y and Z. These buttons will set the mode to "D" and the sorting vector (Direction) to one of the X, Y or Z directions: (1,0,0), (0,1,0) and (0,0,1) respectively. The preset buttons are only visible as long as the sorting vector socket is not connected.
+
+References:
+The algorythm to compute the area is based on descriptions found at this address: http://geomalgorithms.com/a01-_area.html#3D%20Polygons
+
+
--- a/index.md
+++ b/index.md
@@ -135,6 +135,7 @@
    SvListModifierNode
    SvFixEmptyObjectsNode
    SvDatetimeStrings
+    SvPolygonSortNode

 ## List Main
    ListJoinNode

--- a/nodes/list_mutators/polygon_sort.py
+++ b/nodes/list_mutators/polygon_sort.py
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+import bpy
+from bpy.props import BoolProperty, EnumProperty, FloatVectorProperty, StringProperty
+from sverchok.node_tree import SverchCustomTreeNode
+from sverchok.data_structure import updateNode, fullList, match_long_repeat
+from sverchok.utils.sv_operator_mixins import SvGenericCallbackWithParams
+from mathutils import Vector
+from math import acos, pi, sqrt
+
+modeItems = [
+    ("P", "Point", "Sort by distance to a point", 0),
+    ("D", "Direction", "Sort by projection along a direction", 1),
+    ("A", "Area", "Sort by surface area", 2),
+    ("NP", "Normal Angle Point", "Sort by normal angle to point", 3),
+    ("ND", "Normal Angle Direction", "Sort by normal angle to direction", 4)]
+
+directions = {"X": [1, 0, 0], "Y": [0, 1, 0], "Z": [0, 0, 1]}
+
+socket_names = {"P": "Point", "D": "Direction", "A": "Area", "NP": "Normal", "ND": "Normal"}
+socket_props = {"P": "point_P", "D": "point_D", "A": "point_D", "NP": "point_P", "ND": "point_D"}
+
+quantity_names = {"P": "Distances", "D": "Distances", "A": "Areas", "NP": "Angles", "ND": "Angles"}
+
+
+def polygon_normal(verts, poly):
+    ''' The normal of the given polygon '''
+    v1 = Vector(verts[poly[0]])
+    v2 = Vector(verts[poly[1]])
+    v3 = Vector(verts[poly[2]])
+    v12 = v2 - v1
+    v23 = v3 - v2
+    normal = v12.cross(v23)
+    normal.normalize()
+
+    return list(normal)
+
+
+def polygon_area(verts, poly):
+    ''' The area of the given polygon '''
+    if len(poly) < 3:  # not a plane - no area
+        return 0
+
+    total = Vector([0, 0, 0])
+    N = len(poly)
+    for i in range(N):
+        vi1 = Vector(verts[poly[i]])
+        vi2 = Vector(verts[poly[(i + 1) % N]])
+        prod = vi1.cross(vi2)
+        total[0] += prod[0]
+        total[1] += prod[1]
+        total[2] += prod[2]
+
+    normal = Vector(polygon_normal(verts, poly))
+    area = abs(total.dot(normal)) / 2
+
+    return area
+
+
+def polygon_center(verts, poly):
+    ''' The center of the given polygon '''
+    vx = 0
+    vy = 0
+    vz = 0
+    for v in poly:
+        vx = vx + verts[v][0]
+        vy = vy + verts[v][1]
+        vz = vz + verts[v][2]
+    n = len(poly)
+    vx = vx / n
+    vy = vy / n
+    vz = vz / n
+
+    return [vx, vy, vz]
+
+
+def polygon_distance_P(verts, poly, P):
+    ''' The distance from the center of the polygon to the given point '''
+    C = polygon_center(verts, poly)
+    CP = [C[0] - P[0], C[1] - P[1], C[2] - P[2]]
+    distance = sqrt(CP[0] * CP[0] + CP[1] * CP[1] + CP[2] * CP[2])
+
+    return distance
+
+
+def polygon_distance_D(verts, poly, D):
+    ''' The projection of the polygon center vector along the given direction '''
+    C = polygon_center(verts, poly)
+    distance = C[0] * D[0] + C[1] * D[1] + C[2] * D[2]
+
+    return distance
+
+
+def polygon_normal_angle_P(verts, poly, P):
+    ''' The angle between the polygon normal and the vector from polygon center to given point '''
+    N = polygon_normal(verts, poly)
+    C = polygon_center(verts, poly)
+    V = [P[0] - C[0], P[1] - C[1], P[2] - C[2]]
+    v1 = Vector(N)
+    v2 = Vector(V)
+    v1.normalize()
+    v2.normalize()
+    angle = acos(v1.dot(v2)) # the angle in radians
+
+    return angle
+
+
+def polygon_normal_angle_D(verts, poly, D):
+    ''' The angle between the polygon normal and the given direction '''
+    N = polygon_normal(verts, poly)
+    v1 = Vector(N)
+    v2 = Vector(D)
+    v1.normalize()
+    v2.normalize()
+    angle = acos(v1.dot(v2)) # the angle in radians
+
+    return angle
+
+
+class SvPolygonSortNode(bpy.types.Node, SverchCustomTreeNode):
+    """
+    Triggers: Polygon, Sorting
+    Tooltip: Sort the polygons by various criteria: distance, angle, area.
+    """
+    bl_idname = 'SvPolygonSortNode'
+    bl_label = 'Polygon Sort'
+
+    def sort_polygons(self, verts, polys, V):
+        ''' Sort polygons and return sorted polygons indices, poly & quantities '''
+
+        if self.mode == "D":
+            quantities = [polygon_distance_D(verts, poly, V) for poly in polys]
+        elif self.mode == "P":
+            quantities = [polygon_distance_P(verts, poly, V) for poly in polys]
+        elif self.mode == "A":
+            quantities = [polygon_area(verts, poly) for poly in polys]
+        elif self.mode == "NP":
+            quantities = [polygon_normal_angle_P(verts, poly, V) for poly in polys]
+        elif self.mode == "ND":
+            quantities = [polygon_normal_angle_D(verts, poly, V) for poly in polys]
+
+        IQ = [(i, q) for i, q in enumerate(quantities)]
+        sortedIQs = sorted(IQ, key=lambda kv: kv[1], reverse=self.descending)
+
+        sortedIndices = [IQ[0] for IQ in sortedIQs]
+        sortedQuantities = [IQ[1] for IQ in sortedIQs]
+        sortedPolys = [polys[i] for i in sortedIndices]
+
+        return sortedIndices, sortedPolys, sortedQuantities
+
+    def update_sockets(self, context):
+        ''' Swap sorting vector input socket to P/D based on selected mode '''
+
+        s = self.inputs[-1]
+        s.name = socket_names[self.mode]
+        s.prop_name = socket_props[self.mode]
+
+        # keep the P/D props values synced when changing mode
+        if self.mode == "P":
+            self.point_P = self.point_D
+        else:  # self.mode == "D"
+            self.point_D = self.point_P
+
+        # update output "Quantities" socket with proper name for the mode
+        o = self.outputs[-1]
+        o.name = quantity_names[self.mode]
+
+    def set_direction(self, operator):
+        self.direction = operator.direction
+        self.mode = "D"
+        return {'FINISHED'}
+
+    def update_xyz_direction(self, context):
+        self.point_D = directions[self.direction]
+
+    def update_mode(self, context):
+        if self.mode == self.last_mode:
+            return
+
+        self.last_mode = self.mode
+        self.update_sockets(context)
+        updateNode(self, context)
+
+    direction = StringProperty(
+        name="Direction", default="X", update=update_xyz_direction)
+
+    mode = EnumProperty(
+        name="Mode", items=modeItems, default="D", update=update_mode)
+
+    last_mode = EnumProperty(
+        name="Last Mode", items=modeItems, default="D")
+
+    point_P = FloatVectorProperty(
+        name="Point P", description="Reference point for distance and angle calculation",
+        size=3, default=(1, 0, 0), update=updateNode)
+
+    point_D = FloatVectorProperty(
+        name="Direction", description="Reference direction for projection and angle calculation",
+        size=3, default=(1, 0, 0), update=updateNode)
+
+    descending = BoolProperty(
+        name="Descending", description="Sort in the descending order",
+        default=False, update=updateNode)
+
+    def sv_init(self, context):
+        self.inputs.new('VerticesSocket', "Verts")
+        self.inputs.new('StringsSocket', "Polys")
+        self.inputs.new('VerticesSocket', "Direction").prop_name = "point_D"
+        self.outputs.new('VerticesSocket', "Vertices")
+        self.outputs.new('StringsSocket', "Polygons")
+        self.outputs.new('StringsSocket', "Indices")
+        self.outputs.new('StringsSocket', "Distances")
+
+    def draw_buttons(self, context, layout):
+        col = layout.column(align=False)
+
+        if not self.inputs[-1].is_linked:
+            row = col.row(align=True)
+            for direction in "XYZ":
+                op = row.operator("node.set_sort_direction", text=direction)
+                op.direction = direction
+
+        col = layout.column(align=True)
+        row = col.row(align=True)
+        row.prop(self, "mode", expand=False, text="")
+        layout.prop(self, "descending")
+
+    def process(self):
+        if not any(s.is_linked for s in self.outputs):
+            return
+
+        inputs = self.inputs
+        input_v = inputs["Verts"].sv_get()
+        input_p = inputs["Polys"].sv_get()
+        input_r = inputs[-1].sv_get()[0]  # reference: direction or point
+
+        params = match_long_repeat([input_v, input_p, input_r])
+
+        iList, vList, pList, qList = [], [], [], []
+        for v, p, r in zip(*params):
+            indices, polys, quantities = self.sort_polygons(v, p, r)
+            iList.append(indices)
+            vList.append(v)
+            pList.append(polys)
+            qList.append(quantities)
+
+        if self.outputs['Vertices'].is_linked:
+            self.outputs['Vertices'].sv_set(vList)
+        if self.outputs['Polygons'].is_linked:
+            self.outputs['Polygons'].sv_set(pList)
+        if self.outputs['Indices'].is_linked:
+            self.outputs['Indices'].sv_set(iList)
+        if self.outputs[-1].is_linked:
+            self.outputs[-1].sv_set(qList) # sorting quantities
+
+
+class SvSetSortDirection(bpy.types.Operator, SvGenericCallbackWithParams):
+    bl_label = "Set sort direction"
+    bl_idname = "node.set_sort_direction"
+    bl_description = "Set the sorting direction along X, Y or Z"
+
+    direction = StringProperty(default="X")
+    fn_name = StringProperty(default="set_direction")
+
+
+def register():
+    bpy.utils.register_class(SvSetSortDirection)
+    bpy.utils.register_class(SvPolygonSortNode)
+
+
+def unregister():
+    bpy.utils.unregister_class(SvPolygonSortNode)
+    bpy.utils.unregister_class(SvSetSortDirection)