[MISC] Improve readability of entity and morph repr.

genesis/engine/entities/base_entity.py

@@ -91,6 +91,12 @@ def material(self):
     def is_built(self):
         return self._solver._scene._is_built
 
+    def _repr_brief(self):
+        return f"{self.__repr_name__()}, idx: {self.idx}, morph: {self._repr_morph()}, material: {self.material}"
+
+    def _repr_morph(self):
+        return f"{self.morph}"
+
     @property
     def name(self) -> str:
         """

genesis/engine/entities/rigid_entity/rigid_entity.py

@@ -1,8 +1,6 @@
 import inspect
 import os
-import xml.etree.ElementTree as ET
 from itertools import chain
-from pathlib import Path
 from typing import TYPE_CHECKING, Literal, Any, NamedTuple, Sequence
 from functools import wraps
 
@@ -1914,47 +1912,7 @@ def zero_all_dofs_velocity(self, envs_idx=None, *, skip_forward=False):
     def _get_morph_identifier(self) -> str:
         if self._enable_heterogeneous:
             return "heterogeneous"
-
-        morph = self._morph
-
-        if isinstance(morph, gs.morphs.Box):
-            return "box"
-        if isinstance(morph, gs.morphs.Sphere):
-            return "sphere"
-        if isinstance(morph, gs.morphs.Cylinder):
-            return "cylinder"
-        if isinstance(morph, gs.morphs.Plane):
-            return "plane"
-        if isinstance(morph, gs.morphs.Mesh):
-            return Path(morph.file).stem
-        if isinstance(morph, gs.morphs.URDF):
-            if isinstance(morph.file, str):
-                # Try to get robot name from URDF file, fall back to filename stem
-                try:
-                    return uu.get_robot_name(morph.file)
-                except (ValueError, ET.ParseError, FileNotFoundError, OSError) as e:
-                    gs.logger.warning(f"Could not extract robot name from URDF: {e}. Using filename stem instead.")
-                    return Path(morph.file).stem
-            return morph.file.name
-        if isinstance(morph, gs.morphs.MJCF):
-            if isinstance(morph.file, str):
-                # Try to get model name from MJCF file, fall back to filename stem
-                model_name = mju.get_model_name(morph.file)
-                if model_name:
-                    return model_name
-                return Path(morph.file).stem
-            return morph.file.name
-        if isinstance(morph, gs.morphs.Drone):
-            if isinstance(morph.file, str):
-                return Path(morph.file).stem
-            return morph.file.name
-        if isinstance(morph, gs.morphs.USD):
-            if morph.prim_path:
-                return morph.prim_path.rstrip("/").split("/")[-1]
-            return Path(morph.file).stem
-        if isinstance(morph, gs.morphs.Terrain):
-            return morph.name if morph.name else "terrain"
-        return "rigid"
+        return self._morph._identifier()
 
     # ------------------------------------------------------------------------------------
     # ----------------------------------- properties -------------------------------------
@@ -2003,6 +1961,11 @@ def morphs(self):
         """All morphs of the entity (main morph + heterogeneous variants if any)."""
         return gs.List((self._morph, *self._morph_heterogeneous))
 
+    def _repr_morph(self):
+        if self._enable_heterogeneous:
+            return f"{len(self.morphs)} morph variants"
+        return f"{self.main_morph}"
+
     @property
     def n_joints(self):
         """The number of `RigidJoint` in the entity."""

genesis/engine/entities/rigid_entity/rigid_equality.py

@@ -92,6 +92,9 @@ def idx(self):
         """
         return self._idx
 
+    def _repr_brief(self):
+        return f"{self.__repr_name__()}, idx: {self.idx}"
+
     @property
     def idx_local(self):
         """

genesis/options/morphs.py

@@ -7,6 +7,7 @@
 
 import os
 import xml.etree.ElementTree as ET
+from pathlib import Path
 from typing import Annotated, Any, ClassVar, Literal
 from typing_extensions import Self
 
@@ -15,6 +16,7 @@
 
 import genesis as gs
 import genesis.utils.geom as gu
+import genesis.utils.mjcf as mju
 import genesis.utils.misc as mu
 import genesis.utils.urdf as uu
 import genesis.ext.urdfpy as urdfpy
@@ -148,6 +150,10 @@ def model_post_init(self, context: Any) -> None:
         if not self.visualization and not self.collision:
             gs.raise_exception("`visualization` and `collision` cannot both be False.")
 
+    def _identifier(self) -> str:
+        # Short identifier used for entity naming and brief repr; defaults to the morph type name.
+        return type(self).__name__.lower()
+
 
 ############################ Nowhere ############################
 class Nowhere(Morph):
@@ -578,7 +584,9 @@ class FileMorph(Morph):
         **This is only used for RigidEntity.**
     """
 
-    file: Any = ""
+    # Shown in the repr header via __repr_name__ (a bounded identifier for in-memory descriptions), so it is kept out
+    # of the field listing to avoid both duplicating it and dumping a whole inline document.
+    file: Any = Field(default="", repr=False)
     scale: Annotated[tuple[PositiveFloat, PositiveFloat, PositiveFloat], Field(strict=False)] | PositiveFloat = 1.0
     decimate: StrictBool | None = None
     decimate_face_num: PositiveInt = 500
@@ -651,8 +659,23 @@ def __init__(
         if scale.ndim > 1 or scale.size not in (1, 3):
             gs.raise_exception("`scale` should be a scalar sequence of length 1 or 3.")
 
+    def _identifier(self) -> str:
+        file = self.file
+        if not isinstance(file, str):
+            return file.name
+        if os.path.exists(file):
+            return Path(file).stem
+        # An in-memory description has no filename to fall back on; subclasses that embed a name (MJCF model,
+        # URDF robot) override this, otherwise the morph type name stands in for the document.
+        return super()._identifier()
+
     def __repr_name__(self):
-        return f"{super().__repr_name__()[:-1]}(file='{self.file}')>"
+        # A real file path is shown verbatim; an MJCF/URDF built in memory has no path on disk, so a bounded
+        # identifier stands in for the document rather than dumping it.
+        file = self.file
+        if isinstance(file, str) and not os.path.exists(file):
+            file = f"<inline {self._identifier()}>"
+        return f"{super().__repr_name__()[:-1]}(file='{file}')>"
 
     def is_format(self, format):
         if not isinstance(self.file, (str, os.PathLike)):
@@ -957,6 +980,11 @@ def model_post_init(self, context: Any) -> None:
         if not is_inline_xml and not self.is_format(MJCF_FORMAT):
             gs.raise_exception(f"Expected `{MJCF_FORMAT}` extension for MJCF file: {self.file}")
 
+    def _identifier(self) -> str:
+        if isinstance(self.file, str) and (name := mju.get_model_name(self.file)):
+            return name
+        return super()._identifier()
+
 
 class URDF(FileMorph):
     """
@@ -1094,6 +1122,14 @@ def is_format(self, format):
             return format == URDF_FORMAT
         return super().is_format(format)
 
+    def _identifier(self) -> str:
+        if isinstance(self.file, str):
+            try:
+                return uu.get_robot_name(self.file)
+            except (ValueError, ET.ParseError, FileNotFoundError, OSError):
+                pass
+        return super()._identifier()
+
 
 class Drone(FileMorph):
     """
@@ -1384,6 +1420,9 @@ def model_post_init(self, context: Any) -> None:
         ):
             gs.raise_exception("`subterrain_size` should be divisible by `horizontal_scale`.")
 
+    def _identifier(self) -> str:
+        return self.name if self.name else super()._identifier()
+
     @property
     def default_params(self):
         return {
@@ -1644,5 +1683,10 @@ def __init__(self, **data):
 
             self.usd_ctx = UsdContext(self.file)
 
+    def _identifier(self) -> str:
+        if self.prim_path:
+            return self.prim_path.rstrip("/").split("/")[-1]
+        return super()._identifier()
+
     def __repr_name__(self):
-        return f"{super().__repr_name__()[:-1]}(file='{self.file}', prim_path='{self.prim_path}')>"
+        return f"{super().__repr_name__()[:-1]}, prim_path='{self.prim_path}')>"

genesis/repr_base.py

@@ -34,22 +34,12 @@ def __repr_name__(self):
         return f"<gs.{'.'.join((*submodule, class_name))}>"
 
     def _repr_briefer(self):
-        repr_str = self.__repr_name__()
-        if hasattr(self, "id"):
-            repr_str += f"(id={self.id})"
-        return repr_str
+        return self.__repr_name__()
 
     def _repr_brief(self):
-        repr_str = self.__repr_name__()
-        if hasattr(self, "id"):
-            repr_str += f": {self.id}"
-        if hasattr(self, "idx"):
-            repr_str += f", idx: {self.idx}"
-        if hasattr(self, "morph"):
-            repr_str += f", morph: {self.morph}"
-        if hasattr(self, "material"):
-            repr_str += f", material: {self.material}"
-        return repr_str
+        # Subclasses carrying brief-worthy state (entities, indexed sub-objects) override this to append their own
+        # fields. The base rendering is just the class name.
+        return self.__repr_name__()
 
     def __repr__(self) -> str:
         # Detect if running under a debugger (VSCode or PyCharm)

genesis/utils/urdf.py

@@ -28,7 +28,7 @@ def get_robot_name(file_path):
     Parameters
     ----------
     file_path : str or Path
-        Path to the URDF file.
+        Path to the URDF file, or inline URDF XML content.
 
     Returns
     -------
@@ -40,9 +40,11 @@ def get_robot_name(file_path):
     ValueError
         If the robot name attribute is missing or empty.
     """
-    path = os.path.join(get_assets_dir(), file_path)
-    tree = ET.parse(path)
-    root = tree.getroot()
+    try:
+        # Inline XML content parses directly; a file path does not and falls back to reading from disk.
+        root = ET.fromstring(file_path)
+    except ET.ParseError:
+        root = ET.parse(os.path.join(get_assets_dir(), file_path)).getroot()
     if root.tag == "robot":
         name = root.attrib.get("name")
         if name:

tests/test_misc.py

@@ -23,6 +23,59 @@ def test_coacd_options_pca_validation():
         gs.options.CoacdOptions(pca=True)
 
 
+@pytest.mark.required
+def test_repr_does_not_crash():
+    inline_mjcf = '<mujoco model="probe"><worldbody><body><geom type="box" size="1 1 1"/></body></worldbody></mujoco>'
+
+    scene = gs.Scene(show_viewer=False)
+    scene.add_entity(morph=gs.morphs.Plane())
+    scene.add_entity(morph=gs.morphs.Box(size=(0.1, 0.1, 0.1)))
+    panda = scene.add_entity(morph=gs.morphs.MJCF(file="xml/franka_emika_panda/panda.xml"))
+    inline = scene.add_entity(morph=gs.morphs.MJCF(file=inline_mjcf))
+    het = scene.add_entity(
+        morph=(
+            gs.morphs.Box(size=(0.2, 0.2, 0.2)),
+            gs.morphs.Cylinder(radius=0.05, height=0.2),
+        ),
+    )
+    scene.add_entity(
+        morph=(
+            gs.morphs.Box(size=(0.2, 0.2, 0.2)),
+            gs.morphs.Sphere(radius=0.1),
+        ),
+        material=gs.materials.Kinematic(),
+    )
+    cam = scene.add_camera(
+        res=(64, 64),
+        pos=(1.0, 1.0, 1.0),
+        lookat=(0.0, 0.0, 0.0),
+    )
+    scene.build(n_envs=2)
+
+    # Every printable object renders without raising, across both the brief and the full colorized form.
+    for obj in (scene, scene.entities, cam, scene.sim.rigid_solver):
+        assert repr(obj)
+    for entity in scene.entities:
+        assert entity._repr_brief()
+        assert repr(entity)
+        for morph in entity.morphs:
+            assert repr(morph)
+        sub_objects = [*entity.links, *entity.joints, *entity.vgeoms]
+        if isinstance(entity, gs.engine.entities.RigidEntity):
+            sub_objects += list(entity.geoms)
+        for sub in sub_objects:
+            assert sub._repr_brief()
+            assert repr(sub)
+
+    # Sanity on the parts worth enforcing.
+    # A file-based morph shows its path; an in-memory description is identified by its model name, not dumped.
+    assert "panda.xml" in repr(panda.main_morph)
+    assert "<inline probe>" in inline.main_morph.__repr_name__()
+    assert inline_mjcf not in repr(inline.main_morph)
+    # A heterogeneous entity reports its variants instead of collapsing to a single ambiguous morph.
+    assert "morph variants" in het._repr_brief()
+
+
 @pytest.mark.required
 def test_scene_destroy_cleans_up_simulator():
     scene = gs.Scene(show_viewer=False)