Fixes for geometry faces

Author: vidartf

js/src/_base/Three.js

@@ -587,18 +587,35 @@ var ThreeModel = widgets.WidgetModel.extend({
 
     // Faces
     convertFaceModelToThree: function(f, propName) {
+        var normal = f[3];
+        if (normal !== undefined && normal !== null) {
+            if (Array.isArray(normal) && normal.length > 0 && Array.isArray(normal[0])) {
+                normal = normal.map(function (value) {
+                    return this.convertVectorModelToThree(value);
+                }, this);
+            } else {
+                normal = this.convertVectorModelToThree(normal);
+            }
+        }
+        var color = f[4];
+        if (color !== undefined && color !== null) {
+            if (Array.isArray(color)) {
+                color = color.map(function (value) {
+                    return new THREE.Color(value);
+                }, this);
+            } else {
+                color = new THREE.Color(color);
+            }
+        }
         var result = new THREE.Face3(
-            f[0],                                   // a
-            f[1],                                   // b
-            f[2],                                   // c
-            this.convertVectorModelToThree(f[3]),   // normal
-            new THREE.Color(f[4]),                  // color
-            f[5]                                    // materialIndex
+            f[0],                                           // a
+            f[1],                                           // b
+            f[2],                                           // c
+            normal,                                         // normal
+            color,                                          // color
+            f[5]                                            // materialIndex
         );
 
-        result.vertexNormals = this.convertVectorArrayModelToThree(f[6]); // vertexNormals
-        result.vertexColors = this.convertColorArrayModelToThree(f[7]);   // vertexColors
-
         return result;
     },
 

pythreejs/traits.py

@@ -1,7 +1,7 @@
 
 from traitlets import (
     Unicode, Int, CInt, Instance, Enum, List, Dict, Float, CFloat,
-    Bool, Tuple, Undefined, TraitError,
+    Bool, Tuple, Undefined, TraitError, Union,
 )
 
 from ipydatawidgets import DataUnion, NDArrayWidget
@@ -41,7 +41,18 @@ def Matrix4(trait_type=CFloat, default=None, **kwargs):
     return List(trait_type, default_value=default, minlen=16, maxlen=16, **kwargs)
 
 def Face3(**kwargs):
-    return Tuple(CInt(), CInt(), CInt(), Vector3(), Unicode(), CInt(), Tuple(), Tuple())
+    return Tuple(
+        CInt(),     # a — Vertex A index.
+        CInt(),     # b — Vertex B index.
+        CInt(),     # c — Vertex C index.
+        Union([     # normal — (optional) Face normal (Vector3) or array of 3 vertex normals.
+            Vector3(),
+            List(Vector3(), minlen=3, maxlen=3)]),
+        Union([     # color — (optional) Face color or array of vertex colors.
+            Unicode(),
+            List(Unicode(), minlen=3, maxlen=3)]),
+        CInt(),     # materialIndex — (optional) which index of an array of materials to associate with the face.
+        )
 
 def Euler(default=None, **kwargs):
     if default is None: