nicer face normal display

meshvis/context.py

@@ -3,7 +3,7 @@ import pythreejs as three
 import numpy as np
 from IPython.display import display
 from .indexed_attribute import *
-from .mesh_helper import calculateFaceNormals
+from .mesh_helper import calculateFaceNormals, calculatePointNormals
 
 class Context(object):
     def __init__(self, width=600, height=400, background_color = '#dddddd'):
@@ -33,8 +33,13 @@ class Context(object):
 
         face_indices = np.array(face_indices)
 
+        mat = None
         # Setup Material
-        mat = three.MeshLambertMaterial(color='#dddddd', colorWrite=shading is not 'hidden')
+        if shading == 'flat' or shading == 'hidden' or shading == 'wireframe':
+            mat = three.MeshLambertMaterial(color='#dddddd', colorWrite=shading is not 'hidden')
+        elif shading == 'phong':
+            mat = three.MeshPhongMaterial(color='#dddddd')
+
         mat.wireframe = shading is 'wireframe'
 
         if z_offset is not 0:
@@ -42,7 +47,9 @@ class Context(object):
             mat.polygonOffsetFactor = z_offset
             mat.polygonOffsetUnits = 0.1
 
-        if normals is None: 
+        if normals is 'vertex': 
+            normals = calculatePointNormals(vertices, face_indices)
+        elif normals is 'face':
             normals = calculateFaceNormals(vertices, face_indices)
 
         # Resolve the given attributes, it's ok if they are None

meshvis/mesh_helper.py

@@ -3,8 +3,21 @@ import numpy as np
 
 
 def calculateNormalEdges(vertices, face_indices, normals, length):
-    resolved_normals = resolve_attributes(face_indices, [normals])[0]
-    vertices, face_indices = stretch_vertices(vertices, face_indices)
+
+    resolved_normals = None
+
+    if isinstance(normals, FaceAttribute):
+        resolved_normals = normals.values
+        face_centers = []
+        for face in face_indices:
+            v1 = np.array(vertices[face[0]])
+            v2 = np.array(vertices[face[1]])
+            v3 = np.array(vertices[face[2]])
+            face_centers.append((v1 + v2 + v3)/3)
+        vertices = face_centers
+    else:
+        resolved_normals = resolve_attributes(face_indices, [normals])[0]
+        vertices, face_indices = stretch_vertices(vertices, face_indices)
 
     edge_vertices = []
     edge_indices = []
@@ -36,7 +49,7 @@ def calculateFaceNormals(vertices, face_indices):
 
     return FaceAttribute(values)
 
-def calculatePointNormals(vertices, face_indices):
+def calculatePointNormals(vertices, face_indices):   
     values = [(np.array([0.0, 0.0, 0.0]), 0)] * len(vertices)
     for face in face_indices:
         v1 = np.array(vertices[face[0]])
@@ -47,7 +60,6 @@ def calculatePointNormals(vertices, face_indices):
         v13 = np.subtract(v3, v1)
        
         norm = np.cross(v12, v13)
-        
 
         values[face[0]] = ( values[face[0]][0] + norm, values[face[0]][1] + 1)
         values[face[1]] = ( values[face[1]][0] + norm, values[face[1]][1] + 1)