Merge pull request #273 from 3b1b/quaternions

Quaternions

camera/camera.py

@@ -547,7 +547,7 @@ class Camera(object):
         points[violator_indices] = rescaled
         return points
 
-    def transform_points_pre_display(self, points, mobject):
+    def transform_points_pre_display(self, mobject, points):
         # Subclasses (like ThreeDCamera) may want to
         # adjust points before they're shown
         return points

camera/three_d_camera.py

@@ -17,6 +17,7 @@ from utils.color import get_shaded_rgb
 from utils.space_ops import rotation_about_z
 from utils.space_ops import rotation_matrix
 from utils.space_ops import center_of_mass
+from utils.simple_functions import fdiv
 
 
 class ThreeDCamera(Camera):
@@ -166,9 +167,15 @@ class ThreeDCamera(Camera):
         points -= frame_center
         points = np.dot(points, rot_matrix.T)
         zs = points[:, 2]
-        zs[zs >= distance] = distance - 0.001
         for i in 0, 1:
-            points[:, i] *= distance / (distance - zs)
+            # Proper projedtion would involve multiplying
+            # x and y by d / (d-z).  But for points with high
+            # z value, this causes weird artifacts, and applying
+            # the exponential helps smooth it out.
+            factor = np.exp(zs / distance)
+            lt0 = zs < 0
+            factor[lt0] = (distance / (distance - zs[lt0]))
+            points[:, i] *= factor
         points += frame_center
         return points
 

mobject/three_d_utils.py

@@ -35,7 +35,7 @@ def get_3d_vmob_end_corner(vmob):
 
 def get_3d_vmob_unit_normal(vmob, point_index):
     n_points = vmob.get_num_points()
-    if vmob.get_num_points() == 0:
+    if len(vmob.get_anchors()) <= 2:
         return np.array(UP)
     i = point_index
     im1 = i - 1 if i > 0 else (n_points - 2)

mobject/three_dimensions.py

@@ -96,7 +96,7 @@ class ParametricSurface(VGroup):
 class Sphere(ParametricSurface):
     CONFIG = {
         "resolution": (12, 24),
-        "radius": 3,
+        "radius": 1,
         "u_min": 0.001,
         "u_max": PI - 0.001,
         "v_min": 0,
@@ -128,8 +128,9 @@ class Cube(VGroup):
 
     def generate_points(self):
         for vect in IN, OUT, LEFT, RIGHT, UP, DOWN:
-            face = ThreeDVMobject(
-                Square(side_length=self.side_length)
+            face = Square(
+                side_length=self.side_length,
+                shade_in_3d=True,
             )
             face.make_jagged()
             face.flip()

utils/config_ops.py

@@ -53,7 +53,6 @@ def digest_config(obj, kwargs, caller_locals={}):
     caller_locals = filtered_locals(caller_locals)
     all_dicts = [kwargs, caller_locals, obj.__dict__]
     all_dicts += static_configs
-    all_new_dicts = [kwargs, caller_locals] + static_configs
     obj.__dict__ = merge_config(all_dicts)
 
 
@@ -62,7 +61,7 @@ def merge_config(all_dicts):
     config = dict()
     for c in all_config:
         key, value = c
-        if not key in config:
+        if key not in config:
             config[key] = value
         else:
             # When two dictionaries have the same key, they are merged.