added Length Node

eeb194f9 · Victor Doval · 5caad0ae · eeb194f9 · eeb194f9 · eeb194f9
--- a/docs/nodes/analyzers/analyzers_index.rst
+++ b/docs/nodes/analyzers/analyzers_index.rst
@@ -14,6 +14,7 @@ Analyzers
   image_components
   kd_tree
   kd_tree_edges_mk2
+   length
   mesh_filter
   mesh_select
   select_similar

--- a/docs/nodes/analyzers/length.rst
+++ b/docs/nodes/analyzers/length.rst
+Length
+=====
+Functionality
+-------------
+Length node is one of the analyzer type. It is used to get the length of any path, no matter the number of its vertices or its world position.
+Inputs / Parameters
+-------------------
+------------------+---------------+-------------+--------------------------------------------------+
+| Param            | Type          | Default     | Description                                      |  
+==================+===============+=============+==================================================+
+| **Vertices**     | Vertices      | None        | Vertices of the edges / path                     | 
+------------------+---------------+-------------+--------------------------------------------------+
+| **Edges**        | Strings       | None        | Edges referenced to vertices                     |
+------------------+---------------+-------------+--------------------------------------------------+
+| **by Edges**     | Boolean       | True        | output individual edges length or the sum of all |
+------------------+---------------+-------------+--------------------------------------------------+
+In the N-Panel you can use the toggle **Output NumPy** to get NumPy arrays in stead of regular lists (makes the node faster). 
+Outputs
+-------
+**Length** will be calculated if **Vertices** inputs are linked, if no **Edges** are supplied the node will use the sequence order to calculate de distances.
+Example of usage
+----------------
+.. image:: https://cloud.githubusercontent.com/assets/5990821/4188452/8f9cbf66-3772-11e4-8735-34462b7da54b.png
+  :alt: LengthDemo1.PNG
+Measuring a Bender curve with the default vertices, with a higher interpolation and by edges
\ No newline at end of file
--- a/index.md
+++ b/index.md
@@ -49,6 +49,7 @@
    SvVolumeNode
    AreaNode
    DistancePPNode
+    SvLengthNode
    CentersPolsNodeMK2
    CentersPolsNodeMK3
    GetNormalsNode

--- a/nodes/analyzer/length.py
+++ b/nodes/analyzer/length.py
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+import bpy
+from bpy.props import BoolProperty
+from sverchok.node_tree import SverchCustomTreeNode
+from sverchok.data_structure import updateNode, match_long_repeat
+import numpy as np
+def edges_aux(vertices):
+    '''create auxiliary edges array '''
+    v_len = [len(v) for v in vertices]
+    v_len_max = max(v_len)
+    np_in = np.arange(v_len_max - 1)
+    np_edges = np.array([np_in, np_in + 1]).T
+    return [np_edges]
+def edges_length(meshes, gates, result):
+    '''calculate edges length '''
+    for vertices, edges in zip(*meshes):
+        np_verts = np.array(vertices)
+        print(np_verts.shape)
+        if type(edges[0]) in (list, tuple):
+            np_edges = np.array(edges)
+        else:
+            np_edges = edges[:len(vertices)-1, :]
+        vect = np_verts[np_edges[:, 0], :] - np_verts[np_edges[:, 1], :]
+        length = np.linalg.norm(vect, axis=1)
+        if not gates[1]:
+            length = np.sum(length)[np.newaxis]
+        result.append(length if gates[0] else length.tolist())
+    return result
+class SvLengthNode(bpy.types.Node, SverchCustomTreeNode):
+    '''
+    Triggers: Path / Edges length
+    Tooltip: Deformation between to states, edge elong a area variation
+    '''
+    bl_idname = 'SvLengthNode'
+    bl_label = 'Length'
+    bl_icon = 'MOD_SIMPLEDEFORM'
+    output_numpy = BoolProperty(
+        name='Output NumPy', description='output NumPy arrays',
+        default=False, update=updateNode)
+    sum_lengths = BoolProperty(
+        name='by Edge', description='individual lengths or the sum of them',
+        default=True, update=updateNode)
+    def draw_buttons(self, context, layout):
+        '''draw buttons on the Node'''
+        layout.prop(self, "sum_lengths", toggle=False)
+    def draw_buttons_ext(self, context, layout):
+        '''draw buttons on the N-panel'''
+        self.draw_buttons(context, layout)
+        layout.prop(self, "output_numpy", toggle=False)
+    def sv_init(self, context):
+        '''create sockets'''
+        sinw = self.inputs.new
+        sonw = self.outputs.new
+        sinw('VerticesSocket', "Verts")
+        sinw('StringsSocket', "Edges")
+        sonw('StringsSocket', "Length")
+    def get_data(self):
+        '''get all data from sockets'''
+        si = self.inputs
+        vertices = si['Verts'].sv_get(default=[[]])
+        edges_in = si['Edges'].sv_get(default=[[]])
+        if len(edges_in[0]) < 1:
+            edges_in = edges_aux(vertices)
+        return match_long_repeat([vertices, edges_in])
+    def ready(self):
+        '''check if there are the needed links'''
+        si = self.inputs
+        so = self.outputs
+        ready = so[0].is_linked and si[0].is_linked
+        return ready
+    def process(self):
+        '''main node function called every update'''
+        so = self.outputs
+        if not self.ready():
+            return
+        result = []
+        gates = []
+        gates.append(self.output_numpy)
+        gates.append(self.sum_lengths)
+        meshes = self.get_data()
+        result = edges_length(meshes, gates, result)
+        so['Length'].sv_set(result)
+def register():
+    '''register class in Blender'''
+    bpy.utils.register_class(SvLengthNode)
+def unregister():
+    '''unregister class in Blender'''
+    bpy.utils.unregister_class(SvLengthNode)