updateeeee

.gitignore

@@ -15,3 +15,4 @@ dist/
 shapenet2kubric/shapenet2kubric.log
 examples/KuBasic/Cone/*
 Dockerfile
+output_tmp/*

kubric/core/objects.py

@@ -89,8 +89,8 @@ def look_at_quat(
 
   # construct the desired coordinate basis front, right, up
   look_at_front = normalize(target - position)
-  look_at_right = normalize(np.cross(world_up, look_at_front), fallback=world_right)
-  look_at_up = normalize(np.cross(look_at_front, look_at_right))
+  look_at_right = normalize(np.cross(up, look_at_front), fallback=world_right)
+  look_at_up = normalize(np.cross(look_at_front, look_at_right), fallback=world_up)
 
   rotation_matrix1 = np.stack([look_at_right, look_at_up, look_at_front])
   rotation_matrix2 = np.stack([right, up, front])

kubric/randomness.py

@@ -177,8 +177,10 @@ def sample_point_in_half_sphere_shell(
   """Uniformly sample points that are in a given distance range from the origin
      and with z >= offset."""
   while True:
-    v = rng.uniform((-outer_radius, -outer_radius, offset),
-                    (outer_radius, outer_radius, outer_radius))
-    len_v = np.linalg.norm(v)
-    if inner_radius <= len_v <= outer_radius:
-      return tuple(v)
+    xyz = rng.normal(0, 1, (3, ))  # normalize(3-dim standard normal) is distributed on the unit sphere surface
+    if xyz[2] < offset:  # if z is less than offset, rejection.
+      continue
+    xyz = xyz / np.linalg.norm(xyz)  # unit vector on the unit sphere surface
+    radius = rng.uniform(inner_radius**3, outer_radius**3) ** (1/3.)  # radius follows surface area of the sphere of radius r
+    xyz = xyz * radius  # projected to the sphere surface of radius r
+    return tuple(xyz.tolist())

kubric/utils.py

@@ -11,20 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from absl.flags import argparse_flags
 
-# Copyright 2022 The Kubric Authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
 import argparse
 import collections
 import copy
@@ -50,11 +38,11 @@
 # Kubric argparser
 # --------------------------------------------------------------------------------------------------
 
-class ArgumentParser(argparse.ArgumentParser):
+class ArgumentParser(argparse_flags.ArgumentParser):
   """An argumentparser with default options, and compatibility with the Blender REPL."""
 
   def __init__(self, *args, **kwargs):
-    argparse.ArgumentParser.__init__(self, *args, **kwargs)
+    super().__init__(*args, **kwargs)
 
     # --- default arguments for kubric
     self.add_argument("--frame_rate", type=int, default=24,