Add sdf test to physics_test

PiperOrigin-RevId: 578139231
Change-Id: I73f7aee2747190c191829904cf2a7f0b3b77506a

Author: quagla

dm_control/mjcf/physics_test.py

@@ -579,7 +579,7 @@ def test_error_when_pickling_synchronizing_array_wrapper(self):
         mjcf_physics._PICKLING_NOT_SUPPORTED.format(type=type(xpos_view))):
       pickle.dumps(xpos_view)
 
-  def test_plugins(self):
+  def test_plugins_elasticity(self):
     root = mjcf.RootElement()
     root.extension.add('plugin', plugin='mujoco.elasticity.cable')
 
@@ -603,7 +603,27 @@ def test_plugins(self):
     composite.geom.rgba = [0.8, 0.2, 0.1, 1]
     composite.geom.condim = 1
 
-    mjcf.Physics.from_mjcf_model(root)
+    physics = mjcf.Physics.from_mjcf_model(root)
+    physics.step()
+
+  def test_plugins_sdf(self):
+    root = mjcf.RootElement()
+    extension = root.extension.add('plugin', plugin='mujoco.sdf.torus')
+    instance = extension.add('instance', name='torus')
+    instance.add('config', key='radius1', value='0.35')
+    instance.add('config', key='radius2', value='0.15')
+
+    # Replicate example in mujoco/model/plugin/elasticity/torus.xml
+    mesh = root.asset.add('mesh', name='torus')
+    mesh.add('plugin', instance='torus')
+
+    body = root.worldbody.add('body', pos=[-1, 0, 3.8])
+    body.add('freejoint')
+    geom = body.add('geom', type='sdf', mesh='torus', rgba=[.2, .2, .8, 1])
+    geom.add('plugin', instance='torus')
+
+    physics = mjcf.Physics.from_mjcf_model(root)
+    physics.step()
 
 if __name__ == '__main__':
   absltest.main()

dm_control/mjcf/schema.xml

@@ -917,7 +917,7 @@
           <children>
             <element name="plugin" repeated="true" namespace="mesh">
               <attributes>
-                <attribute name="name" type="identifier"/>
+                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1208,7 +1208,7 @@
           <children>
             <element name="plugin" repeated="true" namespace="body">
               <attributes>
-                <attribute name="name" type="identifier"/>
+                <attribute name="name" type="string"/>
                 <attribute name="plugin" type="string"/>
                 <attribute name="instance" type="reference" reference_namespace="plugin"/>
               </attributes>
@@ -1304,7 +1304,7 @@
               <children>
                 <element name="plugin" repeated="true" namespace="geom">
                   <attributes>
-                    <attribute name="name" type="identifier"/>
+                    <attribute name="name" type="string"/>
                     <attribute name="plugin" type="string"/>
                     <attribute name="instance" type="reference" reference_namespace="plugin"/>
                   </attributes>