Improve lighting in soccer pitch.

Plane geoms in mujoco don't actually have a height, they extend infinitely downward. Instead, the third number in the size argument represents the size of the grid which is used for rendering lighting. Lighting values for the plane are calculated at each grid vertex and interpolated in between. The current large grid size is what's causing the lighting artifacts we've been seeing in soccer videos.

This CL reduces the grid size, which makes lighting on the ground look much more realistic. It also renames the grid size variable to reflect its true purpose.]

PiperOrigin-RevId: 300565743
Change-Id: I9c5810cbaec576eeb012f584ad7c1dc659faa4cd

Author: siegeln

dm_control/locomotion/soccer/pitch.py

@@ -32,7 +32,7 @@
 _WALL_HEIGHT = 10.
 _WALL_THICKNESS = .5
 _SIDE_WIDTH = 32. / 6.
-_GROUND_GEOM_HEIGHT = 0.5
+_GROUND_GEOM_GRID_RATIO = 1. / 100  # Grid size for lighting.
 _FIELD_BOX_CONTACT_BIT = 1 << 7  # Use a higher bit to prevent potential clash.
 
 _DEFAULT_PITCH_SIZE = (12, 9)
@@ -131,7 +131,7 @@ def _build(self,
         'geom',
         type='plane',
         material=self._ground_material,
-        size=list(self._size) + [_GROUND_GEOM_HEIGHT])
+        size=list(self._size) + [max(self._size) * _GROUND_GEOM_GRID_RATIO])
 
     # Build walls.
     self._walls = []
@@ -323,7 +323,8 @@ def initialize_episode_mjcf(self, random_state):
                                                self._top_camera_distance)
 
     # Resize ground geom size.
-    self._ground_geom.size = list(self._size) + [_GROUND_GEOM_HEIGHT]
+    self._ground_geom.size = list(
+        self._size) + [max(self._size) * _GROUND_GEOM_GRID_RATIO]
 
     # Resize and reposition walls and roof geoms.
     for i, (wall_pos, _) in enumerate(_wall_pos_xyaxes(self._size)):

setup.py

@@ -166,7 +166,7 @@ def find_data_files(package_dir, patterns):
 
 setup(
     name='dm_control',
-    version='0.0.300079494',
+    version='0.0.300565743',
     description='Continuous control environments and MuJoCo Python bindings.',
     author='DeepMind',
     license='Apache License, Version 2.0',