model_primitives_topology.py

        # in case cursor has moved
        curloc = bpy.context.scene.cursor.location

        bpy.ops.object.mode_set(mode="EDIT")
        bpy.ops.mesh.reveal()
        bpy.ops.mesh.select_all(action="SELECT")
        bpy.ops.mesh.delete(type="VERT")
        bpy.ops.mesh.primitive_xyz_function_surface(
            x_eq=x_eq,
            y_eq=y_eq,
            z_eq=z_eq,
            range_u_min=u_min,
            range_u_max=u_max,
            range_v_min=v_min,
            range_v_max=v_max,
        )
        bpy.ops.mesh.select_all(action="SELECT")
        # extra work:
        bpy.ops.transform.translate(value=(obloc - curloc), proportional_size=1)
        # XXX TODO : https://devtalk.blender.org/t/bpy-ops-transform-rotate-option-axis/6235/7
        # to complete necessary extra work rotation, after updating from blender version > 2.92
        # update and uncomment below, but simple axis deprecated since 2.8
        # bpy.ops.transform.rotate(axis=obrot, proportional_size=1)

        bpy.ops.mesh.hide(unselected=False)
        bpy.ops.object.mode_set(mode="OBJECT")

    if not ob:
        bpy.ops.mesh.primitive_xyz_function_surface(
            x_eq=x_eq,
            y_eq=y_eq,
            z_eq=z_eq,
            range_u_min=u_min,
            range_u_max=u_max,
            range_v_min=v_min,
            range_v_max=v_max,
        )
        ob = context.object
        ob.name = ob.data.name = "PovParametric"

        ob.pov.u_min = u_min
        ob.pov.u_max = u_max
        ob.pov.v_min = v_min
        ob.pov.v_max = v_max
        ob.pov.x_eq = x_eq
        ob.pov.y_eq = y_eq
        ob.pov.z_eq = z_eq

        bpy.ops.object.mode_set(mode="EDIT")
        bpy.ops.mesh.hide(unselected=False)
        bpy.ops.object.mode_set(mode="OBJECT")
        ob.data.auto_smooth_angle = 0.6
        bpy.ops.object.shade_smooth()
        ob.pov.object_as = "PARAMETRIC"
        ob.update_tag() # as prop set via python not updated in depsgraph
        return{'FINISHED'}

class POV_OT_parametric_add(Operator):
    """Add the representation of POV parametric surfaces using pov_parametric_define() function."""

    bl_idname = "pov.addparametric"
    bl_label = "Parametric"
    bl_description = "Add Paramertic"
    bl_options = {'REGISTER', 'UNDO'}
    COMPAT_ENGINES = {"POVRAY_RENDER"}

    # Keep in sync within model_properties.py section Parametric primitive
    # as this allows interactive update
    u_min: FloatProperty(name="U Min", description="", default=0.0)
    v_min: FloatProperty(name="V Min", description="", default=0.0)
    u_max: FloatProperty(name="U Max", description="", default=6.28)
    v_max: FloatProperty(name="V Max", description="", default=12.57)
    x_eq: StringProperty(maxlen=1024, default="cos(v)*(1+cos(u))*sin(v/8)")
    y_eq: StringProperty(maxlen=1024, default="sin(u)*sin(v/8)+cos(v/8)*1.5")
    z_eq: StringProperty(maxlen=1024, default="sin(v)*(1+cos(u))*sin(v/8)")

    def execute(self, context):
        props = self.properties
        u_min = props.u_min
        v_min = props.v_min
        u_max = props.u_max
        v_max = props.v_max
        x_eq = props.x_eq
        y_eq = props.y_eq
        z_eq = props.z_eq
        try:
            pov_parametric_define(context, self, None)
            self.report(
                {"INFO"},
                "This native POV-Ray primitive " "won't have any vertex to show in edit mode",
            )
        except AttributeError:
            self.report({"INFO"}, "Please enable Add Mesh: Extra Objects addon")
        return {"FINISHED"}


class POV_OT_parametric_update(Operator):
    """Update the representation of POV parametric surfaces.

    Delete its previous proxy geometry and rerun pov_parametric_define() function
    with the new parameters"""

    bl_idname = "pov.parametric_update"
    bl_label = "Update"
    bl_description = "Update parametric object"
    bl_options = {'REGISTER', 'UNDO'}
    COMPAT_ENGINES = {"POVRAY_RENDER"}

    @classmethod
    def poll(cls, context):
        engine = context.scene.render.engine
        ob = context.object
        return ob and ob.data and ob.type == "MESH" and engine in cls.COMPAT_ENGINES

    def execute(self, context):

        pov_parametric_define(context, None, context.object)

        return {"FINISHED"}


# -----------------------------------------------------------------------------


class POV_OT_polygon_to_circle_add(Operator):
    """Add the proxy mesh for POV Polygon to circle lofting macro"""

    bl_idname = "pov.addpolygontocircle"
    bl_label = "Polygon To Circle Blending"
    bl_description = "Add Polygon To Circle Blending Surface"
    bl_options = {'REGISTER', 'UNDO'}
    COMPAT_ENGINES = {"POVRAY_RENDER"}

    # Keep in sync within model_properties.py section PolygonToCircle properties
    # as this allows interactive update
    polytocircle_resolution: IntProperty(
        name="Resolution", description="", default=3, min=0, max=256
    )
    polytocircle_ngon: IntProperty(name="NGon", description="", min=3, max=64, default=5)
    polytocircle_ngonR: FloatProperty(name="NGon Radius", description="", default=0.3)
    polytocircle_circleR: FloatProperty(name="Circle Radius", description="", default=1.0)

    def execute(self, context):
        props = self.properties
        ngon = props.polytocircle_ngon
        ngonR = props.polytocircle_ngonR
        circleR = props.polytocircle_circleR
        resolution = props.polytocircle_resolution
        # layers = 20*[False]
        # layers[0] = True
        bpy.ops.mesh.primitive_circle_add(
            vertices=ngon, radius=ngonR, fill_type="NGON", enter_editmode=True
        )
        bpy.ops.transform.translate(value=(0, 0, 1))
        bpy.ops.mesh.subdivide(number_cuts=resolution)
        numCircleVerts = ngon + (ngon * resolution)
        bpy.ops.mesh.select_all(action="DESELECT")
        bpy.ops.mesh.primitive_circle_add(
            vertices=numCircleVerts, radius=circleR, fill_type="NGON", enter_editmode=True
        )
        bpy.ops.transform.translate(value=(0, 0, -1))
        bpy.ops.mesh.select_all(action="SELECT")
        bpy.ops.mesh.bridge_edge_loops()
        if ngon < 5:
            bpy.ops.mesh.select_all(action="DESELECT")
            bpy.ops.mesh.primitive_circle_add(
                vertices=ngon, radius=ngonR, fill_type="TRIFAN", enter_editmode=True
            )
            bpy.ops.transform.translate(value=(0, 0, 1))
            bpy.ops.mesh.select_all(action="SELECT")
            bpy.ops.mesh.remove_doubles()
        bpy.ops.object.mode_set(mode="OBJECT")
        ob = context.object
        ob.name = "Polygon_To_Circle"
        ob.pov.ngon = ngon
        ob.pov.ngonR = ngonR
        ob.pov.circleR = circleR
        bpy.ops.object.mode_set(mode="EDIT")
        bpy.ops.mesh.hide(unselected=False)
        bpy.ops.object.mode_set(mode="OBJECT")
        #ob.data.auto_smooth_angle = 0.1
        #bpy.ops.object.shade_smooth()
        ob.pov.object_as = "POLYCIRCLE"
        ob.update_tag() # as prop set via python not updated in depsgraph
        return {"FINISHED"}


classes = (
    POV_OT_lathe_add,
    POV_OT_superellipsoid_add,
    POV_OT_superellipsoid_update,
    POV_OT_supertorus_add,
    POV_OT_supertorus_update,
    POV_OT_loft_add,
    POV_OT_isosurface_add,
    POV_OT_isosurface_update,
    POV_OT_isosurface_box_add,
    POV_OT_isosurface_sphere_add,
    POV_OT_sphere_sweep_add,
    POV_OT_blobsphere_add,
    POV_OT_blobcapsule_add,
    POV_OT_blobplane_add,
    POV_OT_blobellipsoid_add,
    POV_OT_blobcube_add,
    POV_OT_height_field_add,
    POV_OT_parametric_add,
    POV_OT_parametric_update,
    POV_OT_polygon_to_circle_add,
)


def register():
    for cls in classes:
        register_class(cls)


def unregister():
    for cls in reversed(classes):
        unregister_class(cls)