Version 2.1.2: Python bindings, OBJ assets support, bugfixes.

PiperOrigin-RevId: 434731612
Change-Id: I0cfda3e7a3d1c72036764986efc252ffa1b8c6b0

python/mujoco/render_test.py

@@ -0,0 +1,81 @@
+# Copyright 2022 DeepMind Technologies Limited
+#
+# 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.
+# ==============================================================================
+"""Tests for MuJoCo Python rendering."""
+
+from absl.testing import absltest
+import mujoco
+import numpy as np
+
+
+@absltest.skipUnless(hasattr(mujoco, 'mjr_render'),
+                     'MuJoCo rendering is disabled')
+class MuJoCoRenderTest(absltest.TestCase):
+
+  def setUp(self):
+    super().setUp()
+    self.gl = mujoco.GLContext(640, 480)
+    self.gl.make_current()
+
+  def tearDown(self):
+    super().tearDown()
+    del self.gl
+
+  def test_can_render(self):
+    """Test that the bindings can successfully render a simple image.
+
+    This test sets up a basic MuJoCo rendering context similar to the example in
+    https://mujoco.readthedocs.io/en/latest/programming.html#visualization
+    It calls `mjr_rectangle` rather than `mjr_render` so that we can assert an
+    exact rendered image without needing golden data. The purpose of this test
+    is to ensure that the bindings can correctly return pixels in Python, rather
+    than to test MuJoCo's rendering pipeline itself.
+    """
+
+    self.model = mujoco.MjModel.from_xml_string('<mujoco><worldbody/></mujoco>')
+    self.data = mujoco.MjData(self.model)
+
+    scene = mujoco.MjvScene(self.model, maxgeom=0)
+    mujoco.mjv_updateScene(
+        self.model, self.data, mujoco.MjvOption(), mujoco.MjvPerturb(),
+        mujoco.MjvCamera(), mujoco.mjtCatBit.mjCAT_ALL.value, scene)
+
+    context = mujoco.MjrContext(
+        self.model,
+        mujoco.mjtFontScale.mjFONTSCALE_150.value)
+    mujoco.mjr_setBuffer(
+        mujoco.mjtFramebuffer.mjFB_OFFSCREEN.value, context)
+
+    # MuJoCo's default render buffer size is 640x480.
+    full_rect = mujoco.MjrRect(0, 0, 640, 480)
+    mujoco.mjr_rectangle(full_rect, 0, 0, 0, 1)
+
+    blue_rect = mujoco.MjrRect(56, 67, 234, 123)
+    mujoco.mjr_rectangle(blue_rect, 0, 0, 1, 1)
+
+    expected_upside_down_image = np.zeros((480, 640, 3), dtype=np.uint8)
+    expected_upside_down_image[67:67+123, 56:56+234, 2] = 255
+
+    upside_down_image = np.empty((480, 640, 3), dtype=np.uint8)
+    mujoco.mjr_readPixels(upside_down_image, None, full_rect, context)
+    np.testing.assert_array_equal(upside_down_image, expected_upside_down_image)
+
+    # Check that mjr_readPixels can accept a flattened array.
+    upside_down_image[:] = 0
+    mujoco.mjr_readPixels(
+        np.reshape(upside_down_image, -1), None, full_rect, context)
+    np.testing.assert_array_equal(upside_down_image, expected_upside_down_image)
+
+if __name__ == '__main__':
+  absltest.main()