add Line.find_index_at_position() which finds the index of the line v…

…ertex that is closest to a point

docs/changes.md

@@ -31,6 +31,7 @@ point in the same cloud of points.
 - add `mesh.cut_closed_surface()`
 - fix `image.clone()` in #1011
 - add `transformations.TransformInterpolator` class
+- add `Line.find_index_at_position()` finds the index of the line vertex that is closest to a point
 
 
 ## Breaking changes

vedo/assembly.py

@@ -72,7 +72,7 @@ def procrustes_alignment(sources, rigid=False):
 
 
 #################################################
-class Group(CommonVisual, vtk.vtkPropAssembly):
+class Group(vtk.vtkPropAssembly):
     """Form groups of generic objects (not necessarily meshes)."""
 
     def __init__(self, objects=()):
@@ -100,6 +100,28 @@ def __init__(self, objects=()):
         self.PickableOff()
 
 
+    def __str__(self):
+        """Print info about Group object."""
+        module = self.__class__.__module__
+        name = self.__class__.__name__
+        out = vedo.printc(
+            f"{module}.{name} at ({hex(id(self))})".ljust(75),
+            bold=True, invert=True, return_string=True,
+        )
+        out += "\x1b[0m"
+        if self.name:
+            out += "name".ljust(14) + ": " + self.name
+            if "legend" in self.info.keys() and self.info["legend"]:
+                out+= f", legend='{self.info['legend']}'"
+            out += "\n"
+
+        n = len(self.unpack())
+        out += "n. of objects".ljust(14) + ": " + str(n) + " "
+        names = [a.name for a in self.unpack() if a.name]
+        if names:
+            out += str(names).replace("'","")[:56]
+        return out.rstrip() + "\x1b[0m"
+
     def __iadd__(self, obj):
         """
         Add an object to the group
@@ -148,43 +170,23 @@ def off(self):
         self.VisibilityOff()
         return self
 
-    def pickable(self, value=None):
-        """Set/get the pickability property of an object."""
+    def pickable(self, value=True):
+        """The pickability property of the Group."""
         if value is None:
             return self.GetPickable()
         self.SetPickable(value)
         return self
-
-    def draggable(self, value=None):
-        """Set/get the draggability property of an object."""
-        if value is None:
-            return self.GetDragable()
-        self.SetDragable(value)
+
+    def use_bounds(self, value=True):
+        """Set the use bounds property of the Group."""
+        self.SetUseBounds(value)
         return self
-
-    def pos(self, x=None, y=None):
-        """Set/Get object 2D position on the screen."""
-        if x is None:  # get functionality
-            return np.array(self.GetPosition())
-
-        if y is None:  # assume x is of the form (x,y)
-            x, y = x
-        self.SetPosition(x, y)
-        return self
-
-    def shift(self, ds):
-        """Add a shift to the current object position on the screen."""
-        p = np.array(self.GetPosition())
-        self.SetPosition(p + ds)
+
+    def print(self):
+        """Print info about the object."""
+        print(self)
         return self
 
-    def bounds(self):
-        """
-        Get the object 2D bounds.
-        Returns a list in format [xmin,xmax, ymin,ymax].
-        """
-        return self.GetBounds()
-
 
 #################################################
 class Assembly(CommonVisual, Actor3DHelper, vtk.vtkAssembly):

vedo/shapes.py

@@ -548,6 +548,19 @@ def eval(self, x):
         v = p0 + seg * (x - w0) / (w1 - w0)
         return v
 
+    def find_index_at_position(self, p):
+        """
+        Find the index of the line vertex that is closest to the point `p`.
+        Note that the returned index can be fractional if `p` is not exactly
+        one of the vertices of the line.
+        """
+        q = self.closest_point(p)
+        a, b = sorted(self.closest_point(q, n=2, return_point_id=True))
+        pts = self.vertices
+        d = np.linalg.norm(pts[a] - pts[b])
+        t = a + np.linalg.norm(pts[a] - q) / d
+        return t
+
     def pattern(self, stipple, repeats=10):
         """
         Define a stipple pattern for dashing the line.
@@ -1222,6 +1235,10 @@ def __init__(self, points,
 
         ![](https://user-images.githubusercontent.com/32848391/65975805-73fd6580-e46f-11e9-8957-75eddb28fa72.png)
 
+        Warning:
+            This class is not necessarily generating the exact number of points
+            as requested by `res`. Some points may be concident and removed.
+
         See also: `Spline` and `CSpline`.
         """
         if isinstance(points, Points):
@@ -1284,6 +1301,10 @@ def __init__(self, points, closed=False, res=None):
                 approximate resolution of the output line.
                 Default is 20 times the number of input points.
 
+        Warning:
+            This class is not necessarily generating the exact number of points
+            as requested by `res`. Some points may be concident and removed.
+
         See also: `Spline` and `KSpline`.
         """
 

vedo/visual.py

@@ -498,6 +498,7 @@ def __init__(self):
 
         self.dataset = None
         self.properties = self.GetProperty()
+        self.name = ""
         self.filename = ""
         self.shape = [] # for images