"Move NURBS curve point" node: add Absolute mode.

docs/nodes/curve/move_nurbs_curve_point.rst

@@ -41,10 +41,12 @@ This node has the following inputs:
 
   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)``.
+* **Vector** / **Point**. This input is available only when **Method** is set
+  to **Move one control point**, **Move control points**, or **Insert knot**.
+  If **Mode** parameter is set to **Relative**, this input specifies the vector
+  for which the curve point at **T** parameter is to be moved. In **Absolute**
+  mode, this input specifies the point where curve point is to be moved to. The
+  default value is ``(1.0, 0.0, 0.0)``.
 
 Parameters
 ----------
@@ -93,6 +95,9 @@ This node has the following parameters:
   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.
+* **Mode**. The available options are **Relative** and **Absolute**. In the
+  **Relative** mode, you specify the movement vector; in the **Absolute** mode,
+  you specify the target point. The default mode is **Relative**.
 
 Outputs
 -------

nodes/curve/move_nurbs_curve_point.py

@@ -39,10 +39,16 @@ class SvNurbsCurveMovePointNode(SverchCustomTreeNode, bpy.types.Node):
             ('INSERT_KNOT', "Insert knot", "Insert additional knot and move several control points", 4)
         ]
 
+    modes = [
+            ('REL', "Relative", "Specify vector by which the point is to be moved", 0),
+            ('ABS', "Absolute", "Specify target place where to place the point", 2)
+        ]
+
     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']
+        self.inputs['Vector'].label = 'Vector' if self.vector_mode == 'REL' else 'Point'
         updateNode(self, context)
 
     method : EnumProperty(
@@ -52,6 +58,12 @@ def update_sockets(self, context):
             default = 'ONE_CPT',
             update = update_sockets)
 
+    vector_mode : EnumProperty(
+            name = "Mode",
+            items = modes,
+            default = 'REL',
+            update = update_sockets)
+
     t_value : FloatProperty(
             name = "T",
             description = "Curve parameter value",
@@ -78,6 +90,8 @@ def update_sockets(self, context):
 
     def draw_buttons(self, context, layout):
         layout.prop(self, 'method')
+        if self.method in ['ONE_CPT', 'MOVE_CPTS', 'INSERT_KNOT']:
+            layout.prop(self, 'vector_mode')
         if self.method == 'MOVE_CPTS':
             layout.prop(self, 'preserve_tangent')
 
@@ -111,6 +125,8 @@ def process(self):
         distance_s = ensure_nesting_level(distance_s, 2)
         vector_s = ensure_nesting_level(vector_s, 3)
 
+        relative = self.vector_mode == 'REL'
+
         curves_out = []
         for params in zip_long_repeat(curve_s, t_value_s, index_s, distance_s, vector_s):
             new_curves = []
@@ -121,7 +137,7 @@ def process(self):
 
                 vector = np.array(vector)
                 if self.method == 'ONE_CPT':
-                    new_curve = move_curve_point_by_moving_control_point(curve, t_value, index, vector)
+                    new_curve = move_curve_point_by_moving_control_point(curve, t_value, index, vector, relative=relative)
                 elif self.method == 'ONE_WEIGHT':
                     new_curve = move_curve_point_by_adjusting_one_weight(curve, t_value, index, distance)
                 elif self.method == 'TWO_WEIGHTS':
@@ -131,9 +147,9 @@ def process(self):
                         tangent = TANGENT_PRESERVE
                     else:
                         tangent = None
-                    new_curve = move_curve_point_by_moving_control_points(curve, t_value, vector, tangent=tangent)
+                    new_curve = move_curve_point_by_moving_control_points(curve, t_value, vector, tangent=tangent, relative=relative)
                 elif self.method == 'INSERT_KNOT':
-                    new_curve = move_curve_point_by_inserting_knot(curve, t_value, vector)
+                    new_curve = move_curve_point_by_inserting_knot(curve, t_value, vector, relative=relative)
                 else:
                     raise Exception("Unsupported method")
 

utils/curve/nurbs_algorithms.py

@@ -606,7 +606,7 @@ def offset_nurbs_curve(curve, offset_vector,
     offset_curve = remove_excessive_knots(offset_curve, tolerance = target_tolerance)
     return offset_curve
 
-def move_curve_point_by_moving_control_point(curve, u_bar, k, vector):
+def move_curve_point_by_moving_control_point(curve, u_bar, k, vector, relative=True):
     """
     Adjust the given curve so that at parameter u_bar it goes through
     the point C[u_bar] + vector instead of C[u_bar].
@@ -626,6 +626,9 @@ def move_curve_point_by_moving_control_point(curve, u_bar, k, vector):
     cpts = curve.get_control_points().copy()
     weights = curve.get_weights()
     vector = np.array(vector)
+    if not relative:
+        src_pt = curve.evaluate(u_bar)
+        vector = vector - src_pt
     distance = np.linalg.norm(vector)
     vector = vector / distance
     functions = SvNurbsBasisFunctions(curve.get_knotvector())
@@ -757,7 +760,7 @@ def move_curve_point_by_adjusting_two_weights(curve, u_bar, k, distance=None, sc
 WEIGHTS_EUCLIDIAN = 'EUCLIDIAN'
 TANGENT_PRESERVE = 'PRESERVE'
 
-def move_curve_point_by_moving_control_points(curve, u_bar, vector, weights_mode = WEIGHTS_NONE, tangent = None):
+def move_curve_point_by_moving_control_points(curve, u_bar, vector, weights_mode = WEIGHTS_NONE, tangent = None, relative=True):
     """
     Adjust the given curve so that at parameter u_bar it goues through
     the point C[u_bar] + vector instead of C[u_bar].
@@ -813,6 +816,9 @@ def move_curve_point_by_moving_control_points(curve, u_bar, vector, weights_mode
     ndim = 3
     cpts = curve.get_control_points().copy()
     curve_weights = curve.get_weights()
+    if not relative:
+        src_pt = curve.evaluate(u_bar)
+        vector = vector - src_pt
     if weights_mode == WEIGHTS_EUCLIDIAN:
         pt0 = curve.evaluate(u_bar)
         pt1 = pt0 + vector
@@ -853,7 +859,7 @@ def move_curve_point_by_moving_control_points(curve, u_bar, vector, weights_mode
     cpts = cpts + d_cpts
     return curve.copy(control_points = cpts)
 
-def move_curve_point_by_inserting_knot(curve, u_bar, vector):
+def move_curve_point_by_inserting_knot(curve, u_bar, vector, relative=True):
     """
     Adjust the given curve so that at parameter u_bar it goues through
     the point C[u_bar] + vector instead of C[u_bar].
@@ -867,6 +873,8 @@ def move_curve_point_by_inserting_knot(curve, u_bar, vector):
         you want the point to be moved
     """
     pt0 = curve.evaluate(u_bar)
+    if not relative:
+        vector = vector - pt0
     p = curve.get_degree()
     curve2 = curve.insert_knot(u_bar, p-1, if_possible=True)
     cpts = curve2.get_control_points().copy()