"Move NURBS curve point" node.

f153ab27 · Ilya Portnov · faad970c · f153ab27 · f153ab27 · f153ab27
--- a/index.md
+++ b/index.md
@@ -70,6 +70,8 @@
    SvDeconstructCurveNode
    SvNurbsCurveNodesNode
    ---
+    SvNurbsCurveMovePointNode
+    ---
    SvCurveInsertKnotNode
    SvCurveRemoveKnotNode
    SvRefineNurbsCurveNode

--- a/nodes/curve/move_nurbs_curve_point.py
+++ b/nodes/curve/move_nurbs_curve_point.py
+# This file is part of project Sverchok. It's copyrighted by the contributors
+# recorded in the version control history of the file, available from
+# its original location https://github.com/nortikin/sverchok/commit/master
+#  
+# SPDX-License-Identifier: GPL3
+# License-Filename: LICENSE
+
+import numpy as np
+
+import bpy
+from bpy.props import FloatProperty, EnumProperty, BoolProperty, IntProperty
+
+from sverchok.node_tree import SverchCustomTreeNode
+from sverchok.data_structure import updateNode, zip_long_repeat, ensure_nesting_level, get_data_nesting_level, repeat_last_for_length
+from sverchok.utils.curve import SvCurve
+from sverchok.utils.curve.nurbs import SvNurbsCurve
+from sverchok.utils.curve.nurbs_algorithms import (
+            move_curve_point_by_moving_control_point,
+            move_curve_point_by_adjusting_one_weight,
+            move_curve_point_by_adjusting_two_weights,
+            move_curve_point_by_moving_control_points,
+            move_curve_point_by_inserting_knot)
+
+class SvNurbsCurveMovePointNode(bpy.types.Node, SverchCustomTreeNode):
+    """
+    Triggers: Move NURBS curve point
+    Tooltip: Adjust NURBS curve to move it's point to another location
+    """
+    bl_idname = 'SvNurbsCurveMovePointNode'
+    bl_label = 'Move NURBS Curve Point'
+    bl_icon = 'OUTLINER_OB_EMPTY'
+    sv_icon = 'SV_CURVE_INSERT_KNOT'
+
+    methods = [
+            ('ONE_CPT', "Move one control point", "Move single control point", 0),
+            ('ONE_WEIGHT', "Adjust one weight", "Change single weight", 1),
+            ('TWO_WEIGHTS', "Adjust two weights", "Change two weights", 2),
+            ('MOVE_CPTS', "Move control points", "Move several control points", 3),
+            ('INSERT_KNOT', "Insert knot", "Insert additional knot and move several control points", 4)
+        ]
+
+    def update_sockets(self, context):
+        self.inputs['Index'].hide_safe = self.method not in ['ONE_CPT', 'ONE_WEIGHT', 'TWO_WEIGHTS']
+        self.inputs['Distance'].hide_safe = self.method not in ['ONE_WEIGHT', 'TWO_WEIGHTS']
+        self.inputs['Vector'].hide_safe = self.method not in ['ONE_CPT', 'MOVE_CPTS', 'INSERT_KNOT']
+        updateNode(self, context)
+
+    method : EnumProperty(
+            name = "Method",
+            description = "How should we modify the curve control points or weights",
+            items = methods,
+            default = 'ONE_CPT',
+            update = update_sockets)
+
+    t_value : FloatProperty(
+            name = "T",
+            description = "Curve parameter value",
+            default = 0.5,
+            update = updateNode)
+
+    idx : IntProperty(
+            name = "Index",
+            description = "Control point or weight index to be adjusted",
+            default = 1,
+            min = 0,
+            update = updateNode)
+
+    distance : FloatProperty(
+            name = "Distance",
+            description = "How far to move the point; negative value mean move in the opposite direction",
+            default = 1.0,
+            update = updateNode)
+
+    def draw_buttons(self, context, layout):
+        layout.prop(self, 'method')
+
+    def sv_init(self, context):
+        self.inputs.new('SvCurveSocket', "Curve")
+        self.inputs.new('SvStringsSocket', "T").prop_name = 't_value'
+        self.inputs.new('SvStringsSocket', "Index").prop_name = 'idx'
+        self.inputs.new('SvStringsSocket', "Distance").prop_name = 'distance'
+        p = self.inputs.new('SvVerticesSocket', "Vector")
+        p.use_prop = True
+        p.default_property = (1.0, 0.0, 0.0)
+        self.outputs.new('SvCurveSocket', "Curve")
+        self.update_sockets(context)
+
+    def process(self):
+        if not any(socket.is_linked for socket in self.outputs):
+            return
+
+        curve_s = self.inputs['Curve'].sv_get()
+        t_value_s = self.inputs['T'].sv_get()
+        index_s = self.inputs['Index'].sv_get()
+        distance_s = self.inputs['Distance'].sv_get()
+        vector_s = self.inputs['Vector'].sv_get()
+
+        input_level = get_data_nesting_level(curve_s, data_types=(SvCurve,))
+        flat_output = input_level < 2
+
+        curve_s = ensure_nesting_level(curve_s, 2, data_types=(SvCurve,))
+        t_value_s = ensure_nesting_level(t_value_s, 2)
+        index_s = ensure_nesting_level(index_s, 2)
+        distance_s = ensure_nesting_level(distance_s, 2)
+        vector_s = ensure_nesting_level(vector_s, 3)
+
+        curves_out = []
+        for params in zip_long_repeat(curve_s, t_value_s, index_s, distance_s, vector_s):
+            new_curves = []
+            for curve, t_value, index, distance, vector in zip_long_repeat(*params):
+                curve = SvNurbsCurve.to_nurbs(curve)
+                if curve is None:
+                    raise Exception("One of curves is not NURBS")
+
+                vector = np.array(vector)
+                if self.method == 'ONE_CPT':
+                    curve = move_curve_point_by_moving_control_point(curve, t_value, index, vector)
+                elif self.method == 'ONE_WEIGHT':
+                    curve = move_curve_point_by_adjusting_one_weight(curve, t_value, index, distance)
+                elif self.method == 'TWO_WEIGHTS':
+                    curve = move_curve_point_by_adjusting_two_weights(curve, t_value, index, distance=distance)
+                elif self.method == 'MOVE_CPTS':
+                    curve = move_curve_point_by_moving_control_points(curve, t_value, vector)
+                elif self.method == 'INSERT_KNOT':
+                    curve = move_curve_point_by_inserting_knot(curve, t_value, vector)
+                else:
+                    raise Exception("Unsupported method")
+
+                new_curves.append(curve)
+
+            if flat_output:
+                curves_out.extend(new_curves)
+            else:
+                curves_out.append(new_curves)
+
+        self.outputs['Curve'].sv_set(curves_out)
+
+def register():
+    bpy.utils.register_class(SvNurbsCurveMovePointNode)
+
+def unregister():
+    bpy.utils.unregister_class(SNurbsCurveMovePointNodevCurveInsertKnotNode)
+
--- a/utils/curve/nurbs_algorithms.py
+++ b/utils/curve/nurbs_algorithms.py
@@ -693,6 +693,8 @@ def move_curve_point_by_moving_control_point(curve, u_bar, k, vector):
    vector = vector / distance
    functions = SvNurbsBasisFunctions(curve.get_knotvector())
    x = functions.fraction(k,p, weights)(np.array([u_bar]))[0]
+    if abs(x) < 1e-6:
+        raise Exception(f"Specified control point #{k} is too far from curve parameter U = {u_bar}")
    alpha = distance / x
    cpts[k] = cpts[k] + alpha * vector
    return curve.copy(control_points = cpts)
@@ -798,6 +800,10 @@ def move_curve_point_by_adjusting_two_weights(curve, u_bar, k, distance=None, sc
    abk = np.linalg.norm(D - pk1) / control_leg_len
    abk1 = np.linalg.norm(C - pk) / control_leg_len

+    eps = 1e-6
+    if abs(ak) < eps or abs(abk) < eps or abs(ak1) < eps or abs(abk1) < eps:
+        raise Exception(f"Specified control point #{k} is too far from curve parameter U = {u_bar}")
+
    numerator = 1.0 - ak - ak1
    numerator_brave = 1.0 - abk - abk1

@@ -813,7 +819,7 @@ def move_curve_point_by_adjusting_two_weights(curve, u_bar, k, distance=None, sc
 WEIGHTS_NONE = 'NONE'
 WEIGHTS_EUCLIDIAN = 'EUCLIDIAN'

-def move_curve_point_by_moving_control_points(curve, u_bar, vector, weight_mode = WEIGHTS_NONE):
+def move_curve_point_by_moving_control_points(curve, u_bar, vector, weights_mode = WEIGHTS_NONE):
    """
    Adjust the given curve so that at parameter u_bar it goues through
    the point C[u_bar] + vector instead of C[u_bar].