Add support for circles in profile editing

src/blenderbim/blenderbim/bim/module/cad/__init__.py

@@ -20,6 +20,7 @@ import bpy
 from . import operator, workspace
 
 classes = (
+    operator.AddIfcCircle,
     operator.CadArcFrom2Points,
     operator.CadArcFrom3Points,
     operator.CadFillet,

src/blenderbim/blenderbim/bim/module/cad/operator.py

@@ -343,3 +343,35 @@ class CadArcFrom3Points(bpy.types.Operator):
         bmesh.update_edit_mesh(mesh)
         mesh.update()
         return {"FINISHED"}
+
+
+class AddIfcCircle(bpy.types.Operator):
+    bl_idname = "bim.add_ifccircle"
+    bl_label = "Add IfcCircle"
+
+    @classmethod
+    def poll(cls, context):
+        obj = context.active_object
+        return bool(obj) and obj.type == "MESH"
+
+    def execute(self, context):
+        obj = context.active_object
+        bpy.ops.object.mode_set(mode="EDIT")
+
+        bm = bmesh.from_edit_mesh(obj.data)
+
+        center = obj.matrix_world.inverted() @ context.scene.cursor.location
+        radius = 0.5
+
+        v1 = bm.verts.new((center[0], center[1] + radius, 0.0))
+        v2 = bm.verts.new((center[0], center[1] - radius, 0.0))
+        bm.verts.index_update()
+        indices = [v1.index, v2.index]
+        bm.edges.new((v1, v2))
+        bmesh.update_edit_mesh(obj.data)
+
+        bpy.ops.object.mode_set(mode="OBJECT")
+        group = obj.vertex_groups.new(name="IFCCIRCLE")
+        group.add(indices, 1, "REPLACE")
+        bpy.ops.object.mode_set(mode="EDIT")
+        return {"FINISHED"}

src/blenderbim/blenderbim/bim/module/cad/workspace.py

@@ -41,12 +41,13 @@ class CadTool(WorkSpaceTool):
         ("bim.cad_fillet", {"type": "F", "value": "PRESS", "shift": True}, {"properties": []}),
         # Enable Mesh Tools add-on to get this amazing tool
         ("mesh.offset_edges", {"type": "O", "value": "PRESS", "shift": True}, {"properties": []}),
-        ("bim.cad_arc_from_2_points", {"type": "C", "value": "PRESS", "shift": True}, {"properties": []}),
+        ("bim.cad_hotkey", {"type": "C", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_C")]}),
         ("bim.cad_hotkey", {"type": "V", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_V")]}),
     )
 
     def draw_settings(context, layout, tool):
-        if context.active_object.data.BIMMeshProperties.is_profile:
+        obj = context.active_object
+        if obj and obj.data and hasattr(obj.data, "BIMMeshProperties") and obj.data.BIMMeshProperties.is_profile:
             row = layout.row(align=True)
             row.label(text="", icon="EVENT_SHIFT")
             row.label(text="", icon="EVENT_Q")
@@ -58,6 +59,11 @@ class CadTool(WorkSpaceTool):
             row.label(text="", icon="EVENT_E")
             row.operator("bim.hotkey", text="Extend").hotkey = "S_E"
 
+            row = layout.row(align=True)
+            row.label(text="", icon="EVENT_SHIFT")
+            row.label(text="", icon="EVENT_C")
+            row.operator("bim.add_ifccircle", text="Circle")
+
             row = layout.row(align=True)
             row.label(text="", icon="EVENT_SHIFT")
             row.label(text="", icon="EVENT_V")
@@ -105,6 +111,12 @@ class CadHotkey(bpy.types.Operator):
         getattr(self, f"hotkey_{self.hotkey}")()
         return {"FINISHED"}
 
+    def hotkey_S_C(self):
+        if self.is_profile():
+            bpy.ops.bim.add_ifccircle()
+        else:
+            bpy.ops.bim.cad_arc_from_2_points()
+
     def hotkey_S_E(self):
         bpy.ops.bim.cad_trim_extend()
 
@@ -115,7 +127,11 @@ class CadHotkey(bpy.types.Operator):
         bpy.ops.bim.cad_mitre()
 
     def hotkey_S_V(self):
-        if bpy.context.active_object.data.BIMMeshProperties.is_profile:
+        if self.is_profile():
             bpy.ops.bim.set_arc_index()
         else:
             bpy.ops.bim.cad_arc_from_3_points()
+
+    def is_profile(self):
+        obj = bpy.context.active_object
+        return obj and obj.data and hasattr(obj.data, "BIMMeshProperties") and obj.data.BIMMeshProperties.is_profile

src/blenderbim/blenderbim/bim/module/geometry/helper.py

@@ -21,7 +21,7 @@ import bmesh
 import mathutils
 import ifcopenshell
 import ifcopenshell.util.unit
-from math import pi
+from math import pi, pow
 from mathutils import Vector, Matrix, geometry
 
 
@@ -113,34 +113,52 @@ class Helper:
         return {"profile": profile, "extrusion": extrusion}
 
     def auto_detect_arbitrary_profile_with_voids(self, obj, mesh):
-        arc_groups = []
+        groups = {"IFCARCINDEX": [], "IFCCIRCLE": []}
         for i, group in enumerate(obj.vertex_groups):
             if "IFCARCINDEX" in group.name:
-                arc_groups.append(i)
+                groups["IFCARCINDEX"].append(i)
+            elif "IFCCIRCLE" in group.name:
+                groups["IFCCIRCLE"].append(i)
 
         bm = bmesh.new()
         bm.from_mesh(mesh)
         bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=1e-5)
+        bmesh.ops.delete(bm, geom=bm.faces, context="FACES_ONLY")
 
         # https://docs.blender.org/api/blender_python_api_2_63_8/bmesh.html#CustomDataAccess
         # This is how we access vertex groups via bmesh, apparently, it's not very intuitive
         deform_layer = bm.verts.layers.deform.active
 
         # Sanity check
-        group_verts = {}
+        group_verts = {"IFCARCINDEX": {}, "IFCCIRCLE": {}}
         for vert in bm.verts:
-            if len(vert.link_edges) != 2:  # Unclosed loop or forked loop
-                return (False, "UNCLOSED_LOOP")
             total_groups = 0
-            for group_index in arc_groups:
+            is_circle = False
-                if group_index in vert[deform_layer]:
+            for group_type, group_indices in groups.items():
-                    group_verts.setdefault(group_index, []).append(vert)
+                for group_index in group_indices:
-                    total_groups += 0
+                    if group_index in vert[deform_layer]:
-            if total_groups > 1:  # A vert can only belong to one arc
+                        if group_type == "IFCCIRCLE":
-                return (False, "AMBIGUOUS_ARC")
+                            is_circle = True
-        for verts in group_verts.values():
+                            print('it is a circle')
-            if len(verts) != 3:  # Each arc needs 3 verts
+                        group_verts[group_type].setdefault(group_index, 0)
-                return (False, "3POINT_ARC")
+                        group_verts[group_type][group_index] += 1
+                        total_groups += 0
+            if total_groups > 1:  # A vert can only belong to one group
+                return (False, "AMBIGUOUS_SPECIAL_VERTEX")
+            elif is_circle:
+                pass # Circles are allowed to be unclosed
+            elif total_groups == 0 and len(vert.link_edges) != 2:  # Unclosed loop or forked loop
+                return (False, "UNCLOSED_LOOP")
+
+        for group_type, group_counts in group_verts.items():
+            if group_type == "IFCARCINDEX":
+                for group_count in group_counts.values():
+                    if group_count != 3: # Each arc needs 3 verts
+                        return (False, "3POINT_ARC")
+            elif group_type == "IFCCIRCLE":
+                for group_count in group_counts.values():
+                    if group_count != 2: # Each circle needs 2 verts
+                        return (False, "CIRCLE")
 
         loop_edges = set(bm.edges)
 
@@ -172,20 +190,31 @@ class Helper:
         for loop in loops:
             loop_vertices = []
             total_edges = len(loop)
-            for i, edge in enumerate(loop):
-                if i + 1 == total_edges and edge.verts[0] in loop[i - 1].verts:
-                    loop_vertices.append(edge.verts[0])
-                elif i + 1 == total_edges and edge.verts[1] in loop[i - 1].verts:
-                    loop_vertices.append(edge.verts[1])
-                elif edge.verts[0] in loop[i + 1].verts:
-                    loop_vertices.append(edge.verts[1])
-                elif edge.verts[1] in loop[i + 1].verts:
-                    loop_vertices.append(edge.verts[0])
 
-            loop_bm = bmesh.new()
+            if total_edges == 1:
-            for vert in loop_vertices:
+                loop_vertices = [loop[0].verts[0], loop[0].verts[1]]
-                loop_bm.verts.new(vert.co)
+            else:
-            face = loop_bm.faces.new(loop_bm.verts)
+                for i, edge in enumerate(loop):
+                    if i + 1 == total_edges and edge.verts[0] in loop[i - 1].verts:
+                        loop_vertices.append(edge.verts[0])
+                    elif i + 1 == total_edges and edge.verts[1] in loop[i - 1].verts:
+                        loop_vertices.append(edge.verts[1])
+                    elif edge.verts[0] in loop[i + 1].verts:
+                        loop_vertices.append(edge.verts[1])
+                    elif edge.verts[1] in loop[i + 1].verts:
+                        loop_vertices.append(edge.verts[0])
+
+            if len(loop_vertices) == 2:
+                # Unofficial convention right now that a loop of 2 verts always is a circle
+                radius = (loop_vertices[0].co - loop_vertices[1].co).length / 2
+                face_area = pi * pow(radius, 2)
+            else:
+                loop_bm = bmesh.new()
+                for vert in loop_vertices:
+                    loop_bm.verts.new(vert.co)
+                face = loop_bm.faces.new(loop_bm.verts)
+                face_area = face.calc_area()
+                loop_bm.free()
 
             loop_vertex_indices = []
             active_arc_id = None
@@ -203,7 +232,7 @@ class Helper:
                     active_arc_id = None
 
                 is_arc = False
-                for group_index in arc_groups:
+                for group_index in groups["IFCARCINDEX"]:
                     if group_index in v[deform_layer]:
                         if active_arc_id is not None and active_arc_id != group_index:
                             incomplete_arc = arc_stack
@@ -229,14 +258,11 @@ class Helper:
                 loop_vertex_indices.append(arc_stack)
 
             loop_vertex_indices.append((loop_vertex_indices[-1][-1], loop_vertex_indices[0][0]))
-            # loop_vertex_indices = [v.index for v in loop_vertices]
 
-            face_area = face.calc_area()
             if face_area > max_area:
                 max_area = face_area
                 outer_loop = loop_vertex_indices
             inner_loops.append(loop_vertex_indices)
-            loop_bm.free()
 
         inner_loops.remove(outer_loop)
 

src/blenderbim/blenderbim/bim/module/model/handler.py

@@ -58,7 +58,6 @@ def load_post(*args):
 
     IfcStore.add_element_listener(opening.element_listener)
     IfcStore.add_element_listener(wall.element_listener)
-    IfcStore.add_element_listener(slab.element_listener)
     IfcStore.add_element_listener(profile.element_listener)
 
     ifcopenshell.api.add_post_listener(

src/blenderbim/blenderbim/bim/module/model/slab.py

@@ -34,7 +34,7 @@ import blenderbim.core.geometry
 import blenderbim.tool as tool
 from bpy.types import SpaceView3D
 from blenderbim.bim.ifc import IfcStore
-from math import pi, degrees
+from math import pi, degrees, sin, cos, radians
 from mathutils import Vector, Matrix
 from ifcopenshell.api.pset.data import Data as PsetData
 from ifcopenshell.api.material.data import Data as MaterialData
@@ -43,71 +43,6 @@ from gpu.types import GPUShader, GPUBatch, GPUIndexBuf, GPUVertBuf, GPUVertForma
 from gpu_extras.batch import batch_for_shader
 
 
-def element_listener(element, obj):
-    blenderbim.bim.handler.subscribe_to(obj, "mode", mode_callback)
-
-
-def mode_callback(obj, data):
-    for obj in set(bpy.context.selected_objects + [bpy.context.active_object]):
-        if (
-            not obj.data
-            or not isinstance(obj.data, (bpy.types.Mesh, bpy.types.Curve, bpy.types.TextCurve))
-            or not obj.BIMObjectProperties.ifc_definition_id
-            or not bpy.context.scene.BIMProjectProperties.is_authoring
-        ):
-            return
-        product = IfcStore.get_file().by_id(obj.BIMObjectProperties.ifc_definition_id)
-        parametric = ifcopenshell.util.element.get_psets(product).get("EPset_Parametric")
-        if not parametric or parametric["Engine"] != "BlenderBIM.DumbLayer3":
-            return
-        if obj.mode == "EDIT":
-            IfcStore.edited_objs.add(obj)
-            ensure_solidify_modifier(obj)
-        else:
-            new_origin = obj.matrix_world @ Vector(obj.bound_box[0])
-            obj.data.transform(
-                Matrix.Translation(
-                    (obj.matrix_world.inverted().to_quaternion() @ (obj.matrix_world.translation - new_origin))
-                )
-            )
-            obj.matrix_world.translation = new_origin
-
-
-def ensure_solidify_modifier(obj):
-    modifier = [m for m in obj.modifiers if m.type == "SOLIDIFY"]
-    if modifier:
-        return modifier[0]
-    depth = obj.dimensions.z
-
-    if obj.mode == "EDIT":
-        bm = bmesh.from_edit_mesh(obj.data)
-    else:
-        bm = bmesh.new()
-        bm.from_mesh(obj.data)
-
-    bmesh.ops.dissolve_limit(bm, angle_limit=pi / 180 * 1, verts=bm.verts, edges=bm.edges)
-    bm.faces.ensure_lookup_table()
-    non_bottom_faces = []
-    for face in bm.faces:
-        if face.normal.z > -0.9:
-            non_bottom_faces.append(face)
-        else:
-            face.normal_flip()
-    bmesh.ops.delete(bm, geom=non_bottom_faces, context="FACES")
-
-    if obj.mode == "EDIT":
-        bmesh.update_edit_mesh(obj.data)
-    else:
-        bm.to_mesh(obj.data)
-
-    bm.free()
-    modifier = obj.modifiers.new("Slab Depth", "SOLIDIFY")
-    modifier.use_even_offset = True
-    modifier.offset = 1
-    modifier.thickness = depth
-    return modifier
-
-
 def generate_footprint(usecase_path, ifc_file, settings):
     footprint_context = ifcopenshell.util.representation.get_context(ifc_file, "Plan", "FootPrint", "SKETCH_VIEW")
     if not footprint_context:
@@ -566,24 +501,21 @@ class EnableEditingExtrusionProfile(bpy.types.Operator):
 
         body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
         extrusion = self.get_extrusion(body)
-        profile = extrusion.SweptArea
         position = Matrix(ifcopenshell.util.placement.get_axis2placement(extrusion.Position).tolist())
         position[0][3] *= self.unit_scale
         position[1][3] *= self.unit_scale
         position[2][3] *= self.unit_scale
-        print('converted', position)
 
         z_values = [v[2] for v in obj.bound_box]
-
-        element = tool.Ifc.get_entity(obj)
-
         origin = obj.matrix_world @ Vector((0, 0, max(z_values)))
         normal = obj.matrix_world.to_quaternion()
 
         self.vertices = []
         self.edges = []
         self.arcs = []
+        self.circles = []
 
+        profile = extrusion.SweptArea
         if profile.is_a("IfcArbitraryClosedProfileDef"):
             self.process_curve(obj, position, profile.OuterCurve)
             if profile.is_a("IfcArbitraryProfileDefWithVoids"):
@@ -599,8 +531,12 @@ class EnableEditingExtrusionProfile(bpy.types.Operator):
             group = obj.vertex_groups.new(name="IFCARCINDEX")
             group.add(arc, 1, "REPLACE")
 
+        for circle in self.circles:
+            group = obj.vertex_groups.new(name="IFCCIRCLE")
+            group.add(circle, 1, "REPLACE")
+
         bpy.ops.object.mode_set(mode="EDIT")
-        DecorationsHandler.install(bpy.context)
+        DecorationsHandler.install(context)
         bpy.ops.wm.tool_set_by_id(name="bim.cad_tool")
         return {"FINISHED"}
 
@@ -625,6 +561,8 @@ class EnableEditingExtrusionProfile(bpy.types.Operator):
                     continue
                 global_point = position @ Vector(self.convert_unit_to_si(point.Coordinates)).to_3d()
                 self.vertices.append(global_point)
+            self.edges.extend([(i, i + 1) for i in range(offset, len(self.vertices))])
+            self.edges[-1] = (len(self.vertices) - 1, offset) # Close the loop
         elif curve.is_a("IfcIndexedPolyCurve"):
             is_arc = False
             if curve.Segments:
@@ -650,11 +588,26 @@ class EnableEditingExtrusionProfile(bpy.types.Operator):
                     global_point = position @ Vector(self.convert_unit_to_si(local_point)).to_3d()
                     self.vertices.append(global_point)
 
-        self.edges.extend([(i, i + 1) for i in range(offset, len(self.vertices))])
+            self.edges.extend([(i, i + 1) for i in range(offset, len(self.vertices))])
-        self.edges[-1] = (len(self.vertices) - 1, offset)
+            self.edges[-1] = (len(self.vertices) - 1, offset) # Close the loop
+        elif curve.is_a("IfcCircle"):
+            center = self.convert_unit_to_si(
+                Matrix(ifcopenshell.util.placement.get_axis2placement(curve.Position).tolist()).col[3].to_3d()
+            )
+            radius = self.convert_unit_to_si(curve.Radius)
+            self.vertices.extend(
+                [
+                    position @ Vector((center[0], center[1] - curve.Radius, 0.0)),
+                    position @ Vector((center[0], center[1] + curve.Radius, 0.0)),
+                ]
+            )
+            self.circles.append([offset, offset + 1])
+            self.edges.append((offset, offset + 1))
 
     def convert_unit_to_si(self, value):
-        return [v * self.unit_scale for v in value]
+        if isinstance(value, (tuple, list)):
+            return [v * self.unit_scale for v in value]
+        return value * self.unit_scale
 
 
 class EditExtrusionProfile(bpy.types.Operator):
@@ -686,10 +639,10 @@ class EditExtrusionProfile(bpy.types.Operator):
             bpy.ops.object.mode_set(mode="EDIT")
             return {"CANCELLED"}
 
-        bm = bmesh.new()
+        self.bm = bmesh.new()
-        bm.from_mesh(obj.data)
+        self.bm.from_mesh(obj.data)
-        bm.verts.ensure_lookup_table()
+        self.bm.verts.ensure_lookup_table()
-        bm.edges.ensure_lookup_table()
+        self.bm.edges.ensure_lookup_table()
 
         if indices["inner_curves"]:
             profile = tool.Ifc.get().createIfcArbitraryProfileDefWithVoids("AREA")
@@ -706,7 +659,7 @@ class EditExtrusionProfile(bpy.types.Operator):
                 results.append(self.create_curve(position, inner_curve))
             profile.InnerCurves = results
 
-        bm.free()
+        self.bm.free()
 
         extrusion.SweptArea = profile
 
@@ -731,10 +684,19 @@ class EditExtrusionProfile(bpy.types.Operator):
 
     def create_curve(self, position, edge_indices, points=None):
         position_i = position.inverted()
+        if len(edge_indices) == 2:
+            diameter = edge_indices[0]
+            p1 = self.bm.verts[diameter[0]].co
+            p2 = self.bm.verts[diameter[1]].co
+            center = self.convert_si_to_unit(list(position_i @ p1.lerp(p2, 0.5)))
+            radius = self.convert_si_to_unit((p1 - p2).length / 2)
+            return tool.Ifc.get().createIfcCircle(
+                tool.Ifc.get().createIfcAxis2Placement2D(tool.Ifc.get().createIfcCartesianPoint(center)), radius
+            )
         if tool.Ifc.get().schema == "IFC2X3":
             points = []
             for edge in edge_indices:
-                local_point = (position_i @ Vector(bm.verts[edge[0]].co)).to_2d()
+                local_point = (position_i @ Vector(self.bm.verts[edge[0]].co)).to_2d()
                 points.append(tool.Ifc.get().createIfcCartesianPoint(self.convert_si_to_unit(local_point)))
             points.append(points[0])
             return tool.Ifc.get().createIfcPolyline(points)
@@ -757,7 +719,9 @@ class EditExtrusionProfile(bpy.types.Operator):
                 break
 
     def convert_si_to_unit(self, value):
-        return [v / self.unit_scale for v in value]
+        if isinstance(value, (tuple, list)):
+            return [v / self.unit_scale for v in value]
+        return value / self.unit_scale
 
 
 class SetArcIndex(bpy.types.Operator):
@@ -807,12 +771,13 @@ class DecorationsHandler:
 
     def __call__(self, context):
         obj = context.active_object
+        if obj.mode != "EDIT":
+            return
+
         bgl.glLineWidth(2)
         bgl.glPointSize(6)
         bgl.glEnable(bgl.GL_BLEND)
         bgl.glEnable(bgl.GL_LINE_SMOOTH)
-        if not obj.data.is_editmode:
-            return
 
         all_vertices = []
         error_vertices = []
@@ -825,11 +790,15 @@ class DecorationsHandler:
         special_edges = []
 
         arc_groups = []
+        circle_groups = []
         for i, group in enumerate(obj.vertex_groups):
             if "IFCARCINDEX" in group.name:
                 arc_groups.append(i)
+            elif "IFCCIRCLE" in group.name:
+                circle_groups.append(i)
 
         arcs = {}
+        circles = {}
 
         bm = bmesh.from_edit_mesh(obj.data)
 
@@ -852,6 +821,15 @@ class DecorationsHandler:
                 arcs.setdefault(group_index, []).append(vertex)
                 special_vertex_indices[vertex.index] = group_index
 
+            is_circle = False
+            for group_index in circle_groups:
+                if group_index in vertex[deform_layer]:
+                    is_circle = True
+                    break
+            if is_circle:
+                circles.setdefault(group_index, []).append(vertex)
+                special_vertex_indices[vertex.index] = group_index
+
             if vertex.select:
                 selected_vertices.append(co)
             else:
@@ -913,6 +891,8 @@ class DecorationsHandler:
         self.shader.uniform_float("color", green)
         batch.draw(self.shader)
 
+        # Draw arcs
+
         arc_centroids = []
         arc_segments = []
         for arc in arcs.values():
@@ -933,7 +913,7 @@ class DecorationsHandler:
             centroid = tool.Cad.get_center_of_arc(points)
             if centroid:
                 arc_centroids.append(tuple(centroid))
-            arc_segments.append(self.generate_3PT_mode_1(pts=points, num_verts=17, make_edges=True))
+            arc_segments.append(self.create_arc_segments(pts=points, num_verts=17, make_edges=True))
 
         batch = batch_for_shader(self.shader, "POINTS", {"pos": arc_centroids})
         self.shader.uniform_float("color", (0.2, 0.2, 0.2, 1))
@@ -944,10 +924,74 @@ class DecorationsHandler:
             self.shader.uniform_float("color", (0.157, 0.565, 1, 1))
             batch.draw(self.shader)
 
+        # Draw circles
+
+        circle_centroids = []
+        circle_segments = []
+        for circle in circles.values():
+            if len(circle) != 2:
+                continue
+            p1 = obj.matrix_world @ circle[0].co
+            p2 = obj.matrix_world @ circle[1].co
+            radius = (p2 - p1).length / 2
+            centroid = p1.lerp(p2, 0.5)
+            circle_centroids.append(tuple(centroid))
+            segments = self.create_circle_segments(360, 20, radius)
+            matrix = obj.matrix_world.copy()
+            matrix.col[3] = centroid.to_4d()
+            segments = [[list(matrix @ Vector(v)) for v in segments[0]], segments[1]]
+            circle_segments.append(segments)
+
+        batch = batch_for_shader(self.shader, "POINTS", {"pos": circle_centroids})
+        self.shader.uniform_float("color", (0.2, 0.2, 0.2, 1))
+        batch.draw(self.shader)
+
+        for verts, edges in circle_segments:
+            batch = batch_for_shader(self.shader, "LINES", {"pos": verts}, indices=edges)
+            self.shader.uniform_float("color", (0.157, 0.565, 1, 1))
+            batch.draw(self.shader)
+
+    def create_matrix(self, p, x, y, z):
+        return Matrix([x, y, z, p]).to_4x4().transposed()
+
     # https://github.com/nortikin/sverchok/blob/master/nodes/generator/basic_3pt_arc.py
-    # This generate_3PT_mode_1 function is taken from Sverchok, licensed under GPL v2-or-later.
+    # This function is taken from Sverchok, licensed under GPL v2-or-later.
+    # This is a combination of the make_verts and make_edges function.
+    def create_circle_segments(self, Angle, Vertices, Radius):
+        if Angle < 360:
+            theta = Angle / (Vertices - 1)
+        else:
+            theta = Angle / Vertices
+        listVertX = []
+        listVertY = []
+        for i in range(Vertices):
+            listVertX.append(Radius * cos(radians(theta * i)))
+            listVertY.append(Radius * sin(radians(theta * i)))
+
+        if Angle < 360 and self.mode_ == 0:
+            sigma = radians(Angle)
+            listVertX[-1] = Radius * cos(sigma)
+            listVertY[-1] = Radius * sin(sigma)
+        elif Angle < 360 and self.mode_ == 1:
+            listVertX.append(0.0)
+            listVertY.append(0.0)
+
+        points = list((x, y, 0) for x, y in zip(listVertX, listVertY))
+
+        listEdg = [(i, i + 1) for i in range(Vertices - 1)]
+
+        if Angle < 360 and self.mode_ == 1:
+            listEdg.append((0, Vertices))
+            listEdg.append((Vertices - 1, Vertices))
+        else:
+            listEdg.append((Vertices - 1, 0))
+
+        return points, listEdg
+
+    # https://github.com/nortikin/sverchok/blob/master/nodes/generator/basic_3pt_arc.py
+    # This function is taken from Sverchok's generate_3PT_mode_1 function, licensed under GPL v2-or-later.
     # No functional modifications have been made.
-    def generate_3PT_mode_1(self, pts=None, num_verts=20, make_edges=False):
+    def create_arc_segments(self, pts=None, num_verts=20, make_edges=False):
         """
         Arc from [start - through - end]
         - call this function only if you have 3 pts,