use contrastcolor as default for mesh edges and vertices

Author: tomvanmele

src/compas/scene/meshobject.py

@@ -60,13 +60,13 @@ def __init__(self, mesh, **kwargs):
         self._mesh = None
         self._vertex_xyz = None
         self.mesh = mesh
-        self.vertexcolor = kwargs.get("vertexcolor", self.color)
-        self.edgecolor = kwargs.get("edgecolor", self.color)
+        self.vertexcolor = kwargs.get("vertexcolor", self.contrastcolor)
+        self.edgecolor = kwargs.get("edgecolor", self.contrastcolor)
         self.facecolor = kwargs.get("facecolor", self.color)
         self.vertexsize = kwargs.get("vertexsize", 1.0)
         self.edgewidth = kwargs.get("edgewidth", 1.0)
         self.show_vertices = kwargs.get("show_vertices", False)
-        self.show_edges = kwargs.get("show_edges", True)
+        self.show_edges = kwargs.get("show_edges", False)
         self.show_faces = kwargs.get("show_faces", True)
 
     @property

src/compas/scene/sceneobject.py

@@ -7,6 +7,7 @@
 from .descriptors.color import ColorAttribute
 from .context import clear
 from .context import get_sceneobject_cls
+from compas.colors import Color
 from compas.geometry import Transformation
 from functools import reduce
 from operator import mul
@@ -68,6 +69,7 @@ def __init__(self, item, **kwargs):
         self._node = None
         self._frame = kwargs.get("frame", None)
         self._transformation = kwargs.get("transformation", None)
+        self._contrastcolor = None
         self.name = kwargs.get("name", item.name or item.__class__.__name__)
         self.color = kwargs.get("color", self.color)
         self.opacity = kwargs.get("opacity", 1.0)
@@ -132,6 +134,19 @@ def worldtransformation(self):
 
         return worldtransformation
 
+    @property
+    def contrastcolor(self):
+        if not self._contrastcolor:
+            if self.color.is_light:
+                self._contrastcolor = self.color.darkened(50)
+            else:
+                self._contrastcolor = self.color.lightened(50)
+        return self._contrastcolor
+
+    @contrastcolor.setter
+    def contrastcolor(self, color):
+        self._contrastcolor = Color.coerce(color)
+
     def add(self, item, **kwargs):
         """Add a child item to the scene object.