Merge pull request #4623 from nortikin/nurbs_move_point

"Move NURBS Curve Point" node

docs/nodes/curve/curve_index.rst

@@ -52,6 +52,7 @@ Curves
    nurbs_curve
    approximate_nurbs_curve
    interpolate_nurbs_curve
+   move_nurbs_curve_point
    insert_knot
    remove_knot
    refine_nurbs_curve

docs/nodes/curve/move_nurbs_curve_point.rst

@@ -0,0 +1,137 @@
+Move NURBS Curve Point
+======================
+
+Functionality
+-------------
+
+This node suggests several ways of adjusting a NURBS curve so that it would go
+through another point at specified position, while keeping most of the curve
+more or less in place.
+
+Different methods of curve adjustment allow different degrees of freedom in
+specifying what do you want to move and where to.
+
+Inputs
+------
+
+This node has the following inputs:
+
+* **Curve**. The NURBS Curve object to be adjusted. This input is mandatory.
+* **T**. The value of curve parameter, point at which is to be moved. The default value is 0.5.
+* **Index**. This input has different meaning for different curve adjustment methods being used:
+
+   * For **Move one control point** method, this is the index of curve control point to be moved.
+   * For **Adjust one weight** method, this is the index of curve weight to be adjusted.
+   * For **Adjust two weights** method, this is the index of first of two curve
+     weights to be adjusted. The second weight adjusted will be the following one.
+   * For other methods, this input is not available.
+
+   The default value is 1.
+
+* **Distance**. The distance for which curve point at **T** parameter is to be moved.
+
+  * For **Adjust one weight** method, positive values mean move the point
+    toward corresponding control point (index of which is defined in **Index**
+    input). Negative values mean movement in the oppposite direction.
+  * For **Adjust two weight** method, positive values mean move the span of
+    curve towards the corresponding curve control polygon leg (the one between
+    control points **Index** and **Index+1**). Negative values mean movement in
+    the opposite direction.
+  * For other methods, this input is not available.
+
+  The default value is 1.0.
+
+* **Vector**. The vector for which the curve point at **T** parameter is to be
+  moved. This input is available only when **Method** is set to **Move one
+  control point**, **Move control points**, or **Insert knot**. The default
+  value is ``(1.0, 0.0, 0.0)``.
+
+Parameters
+----------
+
+This node has the following parameters:
+
+* **Method**. The method to be used to adjust the curve. The following methods are available:
+
+  * **Move one control point**. The node will move exactly one control point of
+    the curve, to move curve point at **T** parameter by **Vector**. The index
+    of control point being moved is specified in the **Index** input. Note that
+    it is not always possible to move arbitrary curve point by arbitrary vector
+    by moving specified control point. In intuitive terms, the point to be
+    moved has to be near control point being moved.
+  * **Adjust one weight**. The node will adjust one weight of the curve, to
+    move curve point at **T** parameter directly towards corresponding control
+    point, or in the opposite direction. The index of the weight being adjusted
+    (and the index of corresponding control point) is specified in the
+    **Index** input. Movement distance is specified in the **Distance** input.
+    Note that it is not always possible to move arbitrary curve point by
+    adjusting the specified curve weight. Also, if you try to move the point
+    too far with this method, you will probably get unexpected curve shapes.
+  * **Adjust two weights**. The node will adjust two weights of the curve, to
+    move curve point at **T** parameter, together with neighbouring curve span,
+    towards the corresponding control polygon leg, or in the opposite
+    direction. The index of the first weight to be adjusted (and corresponding
+    control point index) is specified in the **Index** input. Note that it is
+    not always possible to move an arbitrary curve point by adjusting the
+    specified weights. Also, if you try to move the point too far with this
+    method, you will probably get unexpected curve shapes.
+  * **Move control points**. The node will move several control points of the
+    curve (approximately ``p`` of them, where ``p`` is the degree of the
+    curve), to move curve point at **T** parameter by the specified vector. The
+    node will automatically figure out which control points have to be moved.
+    This algorithms gives most smooth results, but it requires more
+    computations, so it is probably less performant.
+  * **Insert knot**. The node will insert additional knot into curve's
+    knotvector, and then move three control points, in order to move curve
+    point at **T** parameter by specified vector. The node will automatically
+    figure out which control points have to be moved.
+
+  The default option is **Move one control point**.
+
+* **Preserve tangent**. This parameter is available only when **Method** is set
+  to **Move control points**. If checked, the node will try to preserve the
+  direction of curve tangent at the point being moved. In many cases, this
+  gives only a slight difference; but sometimes this will make the result
+  smoother. Unchecked by default.
+
+Outputs
+-------
+
+This node has the following output:
+
+* **Curve**. The adjusted curve.
+
+Examples of Usage
+-----------------
+
+An illustration of **Move one control point** method. Here, black is the
+original curve; dark blue is it's control polygon; light blue point is the
+point at T parameter on the original curve. Green is the resulting curve, and
+big green point is the resulting point. In this case, only control point number
+7 is moved.
+
+.. image:: https://user-images.githubusercontent.com/284644/186957079-ceee637d-be54-4d26-8474-04dd4543a011.png
+
+An example of **Adjust one weight** method. Here, the blue point is moved
+towards the control point number 8. Curve control points are not moved, only
+one curve weight is changed.
+
+.. image:: https://user-images.githubusercontent.com/284644/186957074-4f520bad-ff48-48d1-a3b4-ebe2fec1d270.png
+
+An example of **Adjust two weights** method. Here, the blue point is pushed
+away from control polygon leg between control points 4 and 5 (note the negative
+value of Distance parameter). Again, control points are not moved, only weights
+are changed.
+
+.. image:: https://user-images.githubusercontent.com/284644/186957069-2bb35686-1d3b-4abb-94cb-fb0fc03a338d.png
+
+An example of **Move control points** method. Here, the blue point is moved by
+specified vector by moving of three control points (6, 7 and 8).
+
+.. image:: https://user-images.githubusercontent.com/284644/186957065-2b465e62-82f7-48ce-a38a-402580dcd7e7.png
+
+An example of **Insert knot** method. The point is moved by inserting a knot,
+thus creating additional control points, and moving three control points.
+
+.. image:: https://user-images.githubusercontent.com/284644/186957056-66fb3952-664a-4368-92e3-ab48487d51b6.png
+

index.md

@@ -70,6 +70,8 @@
     SvDeconstructCurveNode
     SvNurbsCurveNodesNode
     ---
+    SvNurbsCurveMovePointNode
+    ---
     SvCurveInsertKnotNode
     SvCurveRemoveKnotNode
     SvRefineNurbsCurveNode

nodes/curve/move_nurbs_curve_point.py

@@ -0,0 +1,154 @@
+# 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, TANGENT_PRESERVE,
+            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_MOVE_CURVE_POINT'
+
+    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)
+
+    preserve_tangent : BoolProperty(
+            name = "Preserve tangent",
+            default = False,
+            update = updateNode)
+
+    def draw_buttons(self, context, layout):
+        layout.prop(self, 'method')
+        if self.method == 'MOVE_CPTS':
+            layout.prop(self, 'preserve_tangent')
+
+    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':
+                    if self.preserve_tangent:
+                        tangent = TANGENT_PRESERVE
+                    else:
+                        tangent = None
+                    curve = move_curve_point_by_moving_control_points(curve, t_value, vector, tangent=tangent)
+                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)
+

nodes/curve/nurbs_curve_nodes.py

@@ -24,7 +24,7 @@ class SvNurbsCurveNodesNode(bpy.types.Node, SverchCustomTreeNode):
     bl_idname = 'SvNurbsCurveNodesNode'
     bl_label = 'NURBS Curve Nodes'
     bl_icon = 'OUTLINER_OB_EMPTY'
-    sv_icon = 'SV_DECONSTRUCT_CURVE'
+    sv_icon = 'SV_CURVE_NODES'
 
     def sv_init(self, context):
         self.inputs.new('SvCurveSocket', "Curve")