Merge branch 'google-deepmind:main' into usd-fixes

python/mujoco/codegen/generate_spec_bindings.py

@@ -39,8 +39,10 @@ def _value_binding_code(
     fullvarname = 'ptr->' + varname
   if field.name.startswith('mjs'):  # all other mjs are raw structs
     fulltype = field.name.replace('mjs', 'raw::Mjs')
-    if field.name != 'mjsPlugin' and field.name != 'mjsOrientation':
-      fulltype = fulltype + '*'  # plugin and orientation are pointers
+    if field.name == 'mjsPlugin' or field.name == 'mjsOrientation':
+      fulltype = fulltype + '&'  # plugin and orientation are not pointers
+    else:
+      fulltype = fulltype + '*'
 
   def_property_args = (
       f'"{varname}"',

python/mujoco/specs.cc

@@ -1017,9 +1017,12 @@ PYBIND11_MODULE(_specs, m) {
   mjsTuple.def("delete", [](raw::MjsTuple& self) { mjs_delete(self.element); });
 
   // ============================= MJSPLUGIN ===================================
-  mjsPlugin.def_property_readonly("id", [](raw::MjsPlugin& self) -> int {
-    return mjs_getId(self.instance);
-  });
+  mjsPlugin.def_property(
+      "id",
+      [](raw::MjsPlugin& self) -> int { return mjs_getId(self.instance); },
+      [](raw::MjsPlugin& self, raw::MjsPlugin* other) {
+        self.instance = other->instance;
+      });
   mjsPlugin.def("delete",
                 [](raw::MjsPlugin& self) { mjs_delete(self.instance); });
 

python/mujoco/specs_test.py

@@ -322,5 +322,35 @@ class SpecsTest(absltest.TestCase):
     self.assertEqual(model.nsite, 10)
     self.assertEqual(model.nsensor, 9)
 
+  def test_plugin(self):
+    xml = """
+    <mujoco>
+      <extension>
+        <plugin plugin="mujoco.elasticity.cable"/>
+      </extension>
+    </mujoco>
+    """
+
+    spec = mujoco.MjSpec()
+    spec.from_string(xml)
+    self.assertIsNotNone(spec.worldbody)
+
+    body = spec.worldbody.add_body()
+    body.plugin.name = 'mujoco.elasticity.cable'
+    body.plugin.id = spec.add_plugin()
+    body.plugin.active = True
+    self.assertEqual(body.plugin.id, 0)
+
+    geom = body.add_geom()
+    geom.type = mujoco.mjtGeom.mjGEOM_BOX
+    geom.size[0] = 1
+    geom.size[1] = 1
+    geom.size[2] = 1
+
+    model = spec.compile()
+    self.assertIsNotNone(model)
+    self.assertEqual(model.nplugin, 1)
+    self.assertEqual(model.body_plugin[1], 0)
+
 if __name__ == '__main__':
   absltest.main()