Raycaster checks (#4186)

* raycaster checks

* node docstring

docs/nodes/analyzer/raycaster_lite.rst

@@ -4,12 +4,12 @@ Raycast
 Functionality
 -------------
 
-Functionality is almost completely analogous to the two built-in blender operators 
-``bpy.context.scene.ray_cast`` and ``object.ray_cast``. 
+Functionality is almost completely analogous to the two built-in blender operators
+``bpy.context.scene.ray_cast`` and ``object.ray_cast``.
 Ray is casted from "start" vector to "end" vector and can hit polygons of input objects.
 
-see docs: 
-`bpy.types.Object.ray_cast <http://www.blender.org/documentation/blender_python_api_2_71_0/bpy.types.Object.html#bpy.types.Object.ray_cast>`_ and 
+see docs:
+`bpy.types.Object.ray_cast <http://www.blender.org/documentation/blender_python_api_2_71_0/bpy.types.Object.html#bpy.types.Object.ray_cast>`_ and
 `bpy.types.Scene.ray_cast <http://www.blender.org/documentation/blender_python_api_2_71_0/bpy.types.Scene.html#bpy.types.Scene.ray_cast>`_
 
 
@@ -41,6 +41,12 @@ Output sockets
 | Success                | ``True`` or ``False`` if ray doesn't hit any polygon.                                  |
 +------------------------+----------------------------------------------------------------------------------------+
 
+Advanced parameters (N-Panel)
+----------------------------
+
+**Safe Check**: Checks the mesh for unreferenced polygons (slows the node but prevents some Blender crashes)
+
+**All Triangles**: Enable if all the incoming faces are triangles to improve the performance of the algorithm
 
 Usage
 -----

nodes/analyzer/raycaster_lite.py

@@ -19,21 +19,36 @@
 import bpy
 from sverchok.node_tree import SverchCustomTreeNode
 from sverchok.data_structure import (updateNode, match_long_cycle as C)
-from mathutils.bvhtree import BVHTree
+from sverchok.utils.bvh_tree import bvh_tree_from_polygons
 
 # zeffii 2017 8 okt
 # airlifted from Kosvor's Raycast nodes..
 
 class SvRaycasterLiteNode(bpy.types.Node, SverchCustomTreeNode):
-    ''' svmesh to Raycast '''
+    """
+    Triggers: Raycast on Mesh
+    Tooltip: Cast rays from arbitrary points on to a mesh a determine hiting location, normal at hitpoint, ray legngth and index of the hitted face.
+    """
     bl_idname = 'SvRaycasterLiteNode'
     bl_label = 'Raycaster'
     bl_icon = 'OUTLINER_OB_EMPTY'
     sv_icon = 'SV_RAYCASTER'
 
     start: bpy.props.FloatVectorProperty(default=(0,0,0), size=3, update=updateNode)
     direction: bpy.props.FloatVectorProperty(default=(0,0,-1), size=3, update=updateNode)
-
+    all_triangles: bpy.props.BoolProperty(
+        name='All Triangles',
+        description='Enable to improve node performance if all inputted polygons are triangles',
+        default=False,
+        update=updateNode)
+    safe_check: bpy.props.BoolProperty(
+        name='Safe Check',
+        description='When disabled polygon indices refering to unexisting points will crash Blender but makes node faster',
+        default=True)
+
+    def draw_buttons_ext(self, context, layout):
+        layout.prop(self, 'all_triangles')
+        layout.prop(self, 'safe_check')
     def sv_init(self, context):
         si = self.inputs.new
         so = self.outputs.new
@@ -50,17 +65,18 @@ def sv_init(self, context):
         so('SvStringsSocket', 'Success')
 
     @staticmethod
-    def svmesh_to_bvh_lists(v, f):
+    def svmesh_to_bvh_lists(v, f, all_tris, safe_check):
         for vertices, polygons in zip(*C([v, f])):
-            yield BVHTree.FromPolygons(vertices, polygons, all_triangles=False, epsilon=0.0)
+            yield bvh_tree_from_polygons(vertices, polygons, all_triangles=all_tris, epsilon=0.0, safe_check=safe_check)
 
     def process(self):
         L, N, I, D, S = self.outputs
         RL = []
+        if not any([s.is_linked for s in self.outputs]):
+            return
+        vert_in, face_in, start_in, direction_in = C([sock.sv_get(deepcopy=False) for sock in self.inputs])
 
-        vert_in, face_in, start_in, direction_in = C([sock.sv_get() for sock in self.inputs])
-
-        for bvh, st, di in zip(*[self.svmesh_to_bvh_lists(vert_in, face_in), start_in, direction_in]):
+        for bvh, st, di in zip(*[self.svmesh_to_bvh_lists(vert_in, face_in, self.all_triangles, self.safe_check), start_in, direction_in]):
             st, di = C([st, di])
             RL.append([bvh.ray_cast(i, i2) for i, i2 in zip(st, di)])