mjx segmentation

doc/mjx.rst

@@ -233,6 +233,7 @@ pytree that should be passed into ``jit``/``vmap``-compiled functions:
         use_shadows=True,
         render_rgb=[True] * ncam,
         render_depth=[False] * ncam,
+        render_seg=[True] * ncam,
         enabled_geom_groups=[0, 1, 2],
     )
 
@@ -246,21 +247,23 @@ volume hierarchy (BVH) and executing the raycaster:
 .. code-block:: python
 
     from mujoco.mjx import get_rgb
+    from mujoco.mjx import get_segmentation
 
     @jax.jit
     def render_fn(mx, d, rc_pytree):
         # 1. Update the BVH for the current scene state
         d = mjx.refit_bvh(mx, d, rc_pytree)
 
-        # 2. Render all configured cameras
-        pixels, _ = mjx.render(mx, d, rc_pytree)
+        # 2. Render all configured cameras, including segmentation
+        pixels, _, segmentation = mjx.render_with_segmentation(mx, d, rc_pytree)
 
-        # 3. Extract the RGB tensor for the first camera (index 0)
+        # 3. Extract the RGB tensor and geom IDs for the first camera (index 0)
         rgb = get_rgb(rc_pytree, 0, pixels)
+        seg = get_segmentation(rc_pytree, 0, segmentation)
 
-        return rgb, d
+        return rgb, seg, d
 
-    rgb, d = render_fn(mx, d, rc.pytree())
+    rgb, seg, d = render_fn(mx, d, rc.pytree())
 
 .. WARNING::
    The batch dimension ``nworld`` is fixed when the render context is created via

mjx/mujoco/mjx/__init__.py

@@ -20,9 +20,9 @@ from mujoco.mjx._src.types import Model
 from mujoco.mjx._src.types import Data
 # isort: on
 
+from mujoco.mjx._src.bvh import refit_bvh
 # pylint:disable=g-importing-member
 from mujoco.mjx._src.collision_driver import collision
-from mujoco.mjx._src.bvh import refit_bvh
 from mujoco.mjx._src.constraint import make_constraint
 from mujoco.mjx._src.derivative import deriv_smooth_vel
 from mujoco.mjx._src.forward import euler
@@ -46,8 +46,10 @@ from mujoco.mjx._src.io import state_size
 from mujoco.mjx._src.passive import passive
 from mujoco.mjx._src.ray import ray
 from mujoco.mjx._src.render import render
+from mujoco.mjx._src.render import render_with_segmentation
 from mujoco.mjx._src.render_util import get_depth
 from mujoco.mjx._src.render_util import get_rgb
+from mujoco.mjx._src.render_util import get_segmentation
 from mujoco.mjx._src.sensor import sensor_acc
 from mujoco.mjx._src.sensor import sensor_pos
 from mujoco.mjx._src.sensor import sensor_vel

mjx/mujoco/mjx/_src/render.py

@@ -15,6 +15,7 @@
 """Render helpers for MJX."""
 
 from typing import Any
+
 # pylint: disable=g-importing-member
 from mujoco.mjx._src.types import Data
 from mujoco.mjx._src.types import Impl
@@ -26,8 +27,8 @@ import mujoco.mjx.warp as mjxw
 def render(m: Model, d: Data, ctx: Any) -> Data:
   """Render."""
   if m.impl == Impl.WARP and d.impl == Impl.WARP and mjxw.WARP_INSTALLED:
-    import mujoco.mjx.warp.render_context as mjxw_rc  # pylint: disable=g-import-not-at-top  # pytype: disable=import-error
-    from mujoco.mjx.warp import render as mjxw_render  # pylint: disable=g-import-not-at-top  # pytype: disable=import-error
+    from mujoco.mjx.warp import render as mjxw_render
+    from mujoco.mjx.warp import render_context as mjxw_rc
 
     if not isinstance(ctx, mjxw_rc.RenderContextPytree):
       raise TypeError(
@@ -38,3 +39,22 @@ def render(m: Model, d: Data, ctx: Any) -> Data:
     return mjxw_render.render(m, d, ctx)
 
   raise NotImplementedError('render only implemented for MuJoCo Warp.')
+
+
+def render_with_segmentation(m: Model, d: Data, ctx: Any) -> Data:
+  """Render and return RGB, depth, and packed segmentation outputs."""
+  if m.impl == Impl.WARP and d.impl == Impl.WARP and mjxw.WARP_INSTALLED:
+    from mujoco.mjx.warp import render as mjxw_render
+    from mujoco.mjx.warp import render_context as mjxw_rc
+
+    if not isinstance(ctx, mjxw_rc.RenderContextPytree):
+      raise TypeError(
+          f'Expected RenderContextPytree, got {type(ctx).__name__}.'
+          ' Use rc.pytree() to get the JAX-compatible handle.'
+      )
+
+    return mjxw_render.render_with_segmentation(m, d, ctx)
+
+  raise NotImplementedError(
+      'render_with_segmentation only implemented for MuJoCo Warp.'
+  )

mjx/mujoco/mjx/_src/render_util.py

@@ -25,6 +25,30 @@ if TYPE_CHECKING:
   from mujoco.mjx.warp.render_context import RenderContextPytree
 
 
+def _get_warp_render_context(rc: 'RenderContextPytree'):
+  """Validates and returns the backing Warp render context."""
+  if not mjxw.WARP_INSTALLED:
+    raise RuntimeError('Warp not installed.')
+
+  from mujoco.mjx.warp import render_context as mjxw_rc
+
+  if not isinstance(rc, mjxw_rc.RenderContextPytree):
+    raise TypeError(
+        f'Expected RenderContextPytree, got {type(rc).__name__}.'
+        ' Use rc.pytree() to get the JAX-compatible handle.'
+    )
+
+  # pylint: disable=protected-access
+  return mjxw_rc._MJX_RENDER_CONTEXT_BUFFERS[(rc.key, None)]
+
+
+def _get_camera_resolution(warp_rc, cam_id: int) -> tuple[int, int]:
+  """Returns the render resolution for a given camera."""
+  width = int(warp_rc.cam_res.numpy()[cam_id][0])
+  height = int(warp_rc.cam_res.numpy()[cam_id][1])
+  return width, height
+
+
 def get_rgb(
     rc: 'RenderContextPytree',
     cam_id: int,
@@ -44,21 +68,9 @@ def get_rgb(
   Raises:
     RuntimeError: If Warp is not installed.
   """
-  if not mjxw.WARP_INSTALLED:
-    raise RuntimeError('Warp not installed.')
-
-  import mujoco.mjx.warp.render_context as mjxw_rc  # pylint: disable=g-import-not-at-top  # pytype: disable=import-error
-
-  if not isinstance(rc, mjxw_rc.RenderContextPytree):
-    raise TypeError(
-        f'Expected RenderContextPytree, got {type(rc).__name__}.'
-        ' Use rc.pytree() to get the JAX-compatible handle.'
-    )
-
-  warp_rc = mjxw_rc._MJX_RENDER_CONTEXT_BUFFERS[(rc.key, None)]  # pylint: disable=protected-access
+  warp_rc = _get_warp_render_context(rc)
   rgb_adr = int(warp_rc.rgb_adr.numpy()[cam_id])
-  width = int(warp_rc.cam_res.numpy()[cam_id][0])
-  height = int(warp_rc.cam_res.numpy()[cam_id][1])
+  width, height = _get_camera_resolution(warp_rc, cam_id)
 
   packed = jax.lax.dynamic_slice_in_dim(
       rgb_data, rgb_adr, width * height, axis=rgb_data.ndim - 1
@@ -92,21 +104,9 @@ def get_depth(
   Raises:
     RuntimeError: If Warp is not installed.
   """
-  if not mjxw.WARP_INSTALLED:
-    raise RuntimeError('Warp not installed.')
-
-  import mujoco.mjx.warp.render_context as mjxw_rc  # pylint: disable=g-import-not-at-top  # pytype: disable=import-error
-
-  if not isinstance(rc, mjxw_rc.RenderContextPytree):
-    raise TypeError(
-        f'Expected RenderContextPytree, got {type(rc).__name__}.'
-        ' Use rc.pytree() to get the JAX-compatible handle.'
-    )
-
-  warp_rc = mjxw_rc._MJX_RENDER_CONTEXT_BUFFERS[(rc.key, None)]  # pylint: disable=protected-access
+  warp_rc = _get_warp_render_context(rc)
   depth_adr = int(warp_rc.depth_adr.numpy()[cam_id])
-  width = int(warp_rc.cam_res.numpy()[cam_id][0])
-  height = int(warp_rc.cam_res.numpy()[cam_id][1])
+  width, height = _get_camera_resolution(warp_rc, cam_id)
 
   raw = jax.lax.dynamic_slice_in_dim(
       depth_data, depth_adr, width * height, axis=depth_data.ndim - 1
@@ -114,3 +114,37 @@ def get_depth(
 
   depth = jnp.clip(raw / depth_scale, 0.0, 1.0)
   return depth.reshape(raw.shape[:-1] + (height, width, 1))
+
+
+def get_segmentation(
+    rc: 'RenderContextPytree',
+    cam_id: int,
+    seg_data: jax.Array,
+) -> jax.Array:
+  """Extract raw geom IDs for a camera.
+
+  Args:
+    rc: RenderContextPytree.
+    cam_id: Camera index to extract.
+    seg_data: Packed segmentation output, shape (..., total_pixels) as integers.
+
+  Returns:
+    Integer segmentation array with shape (..., H, W).
+    Any leading batch axes in `seg_data` are preserved.
+
+  Raises:
+    RuntimeError: If Warp is not installed.
+    ValueError: If segmentation is not enabled for the selected camera.
+  """
+  warp_rc = _get_warp_render_context(rc)
+  seg_adr = int(warp_rc.seg_adr.numpy()[cam_id])
+  if seg_adr < 0:
+    raise ValueError(
+        f'Camera {cam_id} was not configured with segmentation rendering.'
+    )
+
+  width, height = _get_camera_resolution(warp_rc, cam_id)
+  packed = jax.lax.dynamic_slice_in_dim(
+      seg_data, seg_adr, width * height, axis=seg_data.ndim - 1
+  )
+  return packed.reshape(packed.shape[:-1] + (height, width))

mjx/mujoco/mjx/_src/render_util_test.py

@@ -28,14 +28,23 @@ from mujoco.mjx.warp.render_context import RenderContextPytree
 _FORCE_TEST = os.environ.get('MJX_WARP_FORCE_TEST', '0') == '1'
 
 
-def _fake_render_context(ncam, width, height):
+def _fake_render_context(ncam, width, height, render_seg=True):
   """Fake RenderContext for testing."""
   rc = mock.MagicMock()
   rgb_adr = np.arange(ncam, dtype=np.int32) * width * height
   depth_adr = np.arange(ncam, dtype=np.int32) * width * height
+  if isinstance(render_seg, bool):
+    render_seg = [render_seg] * ncam
+  seg_adr = np.full(ncam, -1, dtype=np.int32)
+  seg_offset = 0
+  for i, enabled in enumerate(render_seg):
+    if enabled:
+      seg_adr[i] = seg_offset
+      seg_offset += width * height
   cam_res = np.tile([width, height], (ncam, 1)).astype(np.int32)
   rc.rgb_adr.numpy.return_value = rgb_adr
   rc.depth_adr.numpy.return_value = depth_adr
+  rc.seg_adr.numpy.return_value = seg_adr
   rc.cam_res.numpy.return_value = cam_res
   return rc
 
@@ -154,6 +163,81 @@ class RenderUtilTest(absltest.TestCase):
 
     self.assertEqual(depth.shape, (nworld, height, width, 1))
 
+  def test_get_segmentation(self):
+    width, height = 4, 4
+    warp_rc = _fake_render_context(1, width, height)
+    rc = mock.MagicMock(spec=RenderContextPytree, key=0)
+    seg_data = jnp.arange(width * height, dtype=jnp.int32)
+
+    with mock.patch.dict(
+        'mujoco.mjx.warp.render_context._MJX_RENDER_CONTEXT_BUFFERS',
+        {(0, None): warp_rc},
+    ):
+      segmentation = jax.jit(
+          render_util.get_segmentation, static_argnums=(0, 1)
+      )(rc, 0, seg_data)
+
+    self.assertEqual(segmentation.shape, (height, width))
+    np.testing.assert_array_equal(
+        np.asarray(segmentation),
+        np.arange(width * height, dtype=np.int32).reshape(height, width),
+    )
+
+  def test_get_segmentation_preserves_leading_dims(self):
+    width, height = 4, 4
+    warp_rc = _fake_render_context(1, width, height)
+    rc = mock.MagicMock(spec=RenderContextPytree, key=0)
+
+    with mock.patch.dict(
+        'mujoco.mjx.warp.render_context._MJX_RENDER_CONTEXT_BUFFERS',
+        {(0, None): warp_rc},
+    ):
+      for leading_shape in ((1,), (3,), (2, 3)):
+        with self.subTest(leading_shape=leading_shape):
+          seg_data = jnp.arange(
+              np.prod(leading_shape) * width * height, dtype=jnp.int32
+          ).reshape(leading_shape + (width * height,))
+          segmentation = jax.jit(
+              render_util.get_segmentation, static_argnums=(0, 1)
+          )(rc, 0, seg_data)
+
+          self.assertEqual(segmentation.shape, leading_shape + (height, width))
+
+  def test_get_segmentation_vmap(self):
+    nworld, width, height = 3, 4, 4
+    warp_rc = _fake_render_context(1, width, height)
+    rc = mock.MagicMock(spec=RenderContextPytree, key=0)
+    seg_data = jnp.arange(nworld * width * height, dtype=jnp.int32).reshape(
+        nworld, width * height
+    )
+
+    with mock.patch.dict(
+        'mujoco.mjx.warp.render_context._MJX_RENDER_CONTEXT_BUFFERS',
+        {(0, None): warp_rc},
+    ):
+      segmentation = jax.jit(
+          jax.vmap(render_util.get_segmentation, in_axes=(None, None, 0)),
+          static_argnums=(0, 1),
+      )(rc, 0, seg_data)
+
+    self.assertEqual(segmentation.shape, (nworld, height, width))
+
+  def test_get_segmentation_raises_for_disabled_camera(self):
+    width, height = 4, 4
+    warp_rc = _fake_render_context(2, width, height, render_seg=[True, False])
+    rc = mock.MagicMock(spec=RenderContextPytree, key=0)
+    seg_data = jnp.arange(width * height, dtype=jnp.int32)
+
+    with mock.patch.dict(
+        'mujoco.mjx.warp.render_context._MJX_RENDER_CONTEXT_BUFFERS',
+        {(0, None): warp_rc},
+    ):
+      with self.assertRaisesWithLiteralMatch(
+          ValueError,
+          'Camera 1 was not configured with segmentation rendering.',
+      ):
+        render_util.get_segmentation(rc, 1, seg_data)
+
 
 if __name__ == '__main__':
   absltest.main()

mjx/mujoco/mjx/warp/io.py

@@ -14,11 +14,12 @@
 # ==============================================================================
 """I/O functions for MJX Warp."""
 
-import mujoco
-from mujoco.mjx.warp import render_context
-import mujoco.mjx.third_party.mujoco_warp as mjw
 import warp as wp
 
+import mujoco
+import mujoco.mjx.third_party.mujoco_warp as mjw
+from mujoco.mjx.warp import render_context
+
 _MJX_RENDER_CONTEXT_COUNTER = 0
 
 
@@ -27,8 +28,11 @@ def _create_context(mjm, nworld, device, **kwargs):
     ctx = mjw.create_render_context(mjm=mjm, nworld=nworld, **kwargs)
     ctx.rgb_data_shape = ctx.rgb_data.shape
     ctx.depth_data_shape = ctx.depth_data.shape
+    ctx.seg_data_shape = ctx.seg_data.shape
+    ctx.seg_data_buffer = ctx.seg_data
     ctx.rgb_data = None
     ctx.depth_data = None
+    ctx.seg_data = None
   return ctx
 
 

mjx/mujoco/mjx/warp/render.py

@@ -14,17 +14,19 @@
 # ==============================================================================
 
 """DO NOT EDIT. This file is auto-generated."""
+
 import dataclasses
 import functools
+
 import jax
+import warp as wp
+
 from mujoco.mjx._src import types
+import mujoco.mjx.third_party.mujoco_warp as mjwarp
+from mujoco.mjx.third_party.mujoco_warp._src import types as mjwp_types
 from mujoco.mjx.warp import ffi
 from mujoco.mjx.warp.render_context import _MJX_RENDER_CONTEXT_BUFFERS
 from mujoco.mjx.warp.render_context import RenderContextPytree
-import mujoco.mjx.third_party.mujoco_warp as mjwarp
-from mujoco.mjx.third_party.mujoco_warp._src import types as mjwp_types
-import warp as wp
-
 
 _m = mjwarp.Model(
     **{f.name: None for f in dataclasses.fields(mjwarp.Model) if f.init}
@@ -122,36 +124,129 @@ def _render_shim(
   render_context = _MJX_RENDER_CONTEXT_BUFFERS[(rc_id, wp.get_device().ordinal)]
   render_context.rgb_data = rgb
   render_context.depth_data = depth
+  render_context.seg_data = render_context.seg_data_buffer
   mjwarp.render(_m, _d, render_context)
 
 
-def _render_jax_impl(m: types.Model, d: types.Data, ctx: RenderContextPytree):
+@ffi.format_args_for_warp
+def _render_with_segmentation_shim(
+    # Model
+    nworld: int,
+    cam_fovy: wp.array2d[float],
+    cam_intrinsic: wp.array2d[wp.vec4],
+    cam_projection: wp.array[int],
+    cam_sensorsize: wp.array[wp.vec2],
+    flex_edge: wp.array[wp.vec2i],
+    flex_radius: wp.array[float],
+    flex_vertadr: wp.array[int],
+    geom_dataid: wp.array2d[int],
+    geom_matid: wp.array2d[int],
+    geom_rgba: wp.array2d[wp.vec4],
+    geom_size: wp.array2d[wp.vec3],
+    geom_type: wp.array[int],
+    light_active: wp.array2d[bool],
+    light_castshadow: wp.array2d[bool],
+    light_type: wp.array2d[int],
+    mat_rgba: wp.array2d[wp.vec4],
+    mat_texid: wp.array3d[int],
+    mat_texrepeat: wp.array2d[wp.vec2],
+    mesh_faceadr: wp.array[int],
+    nlight: int,
+    # Data
+    cam_xmat: wp.array2d[wp.mat33],
+    cam_xpos: wp.array2d[wp.vec3],
+    flexvert_xpos: wp.array2d[wp.vec3],
+    geom_xmat: wp.array2d[wp.mat33],
+    geom_xpos: wp.array2d[wp.vec3],
+    light_xdir: wp.array2d[wp.vec3],
+    light_xpos: wp.array2d[wp.vec3],
+    # Registry
+    rc_id: int,
+    rgb: wp.array2d[wp.uint32],
+    depth: wp.array2d[wp.float32],
+    seg: wp.array2d[int],
+):
+  _m.stat = _s
+  _m.opt = _o
+  _m.callback = _cb
+  _d.efc = _e
+  _d.contact = _c
+  _m.cam_fovy = cam_fovy
+  _m.cam_intrinsic = cam_intrinsic
+  _m.cam_projection = cam_projection
+  _m.cam_sensorsize = cam_sensorsize
+  _m.flex_edge = flex_edge
+  _m.flex_radius = flex_radius
+  _m.flex_vertadr = flex_vertadr
+  _m.geom_dataid = geom_dataid
+  _m.geom_matid = geom_matid
+  _m.geom_rgba = geom_rgba
+  _m.geom_size = geom_size
+  _m.geom_type = geom_type
+  _m.light_active = light_active
+  _m.light_castshadow = light_castshadow
+  _m.light_type = light_type
+  _m.mat_rgba = mat_rgba
+  _m.mat_texid = mat_texid
+  _m.mat_texrepeat = mat_texrepeat
+  _m.mesh_faceadr = mesh_faceadr
+  _m.nlight = nlight
+  _d.cam_xmat = cam_xmat
+  _d.cam_xpos = cam_xpos
+  _d.flexvert_xpos = flexvert_xpos
+  _d.geom_xmat = geom_xmat
+  _d.geom_xpos = geom_xpos
+  _d.light_xdir = light_xdir
+  _d.light_xpos = light_xpos
+  _d.nworld = nworld
+  render_context = _MJX_RENDER_CONTEXT_BUFFERS[(rc_id, wp.get_device().ordinal)]
+  render_context.rgb_data = rgb
+  render_context.depth_data = depth
+  render_context.seg_data = seg
+  mjwarp.render(_m, _d, render_context)
+
+
+_RENDER_STAGE_IN_ARGNAMES = set([
+    'cam_fovy',
+    'cam_intrinsic',
+    'cam_xmat',
+    'cam_xpos',
+    'geom_matid',
+    'geom_rgba',
+    'geom_size',
+    'geom_xmat',
+    'geom_xpos',
+    'light_castshadow',
+    'light_type',
+    'mat_rgba',
+    'mat_texid',
+])
+
+
+def _render_jax_impl(
+    m: types.Model,
+    d: types.Data,
+    ctx: RenderContextPytree,
+    with_segmentation: bool = False,
+):
   render_ctx = _MJX_RENDER_CONTEXT_BUFFERS[(ctx.key, None)]
   output_dims = {
       'rgb': render_ctx.rgb_data_shape,
       'depth': render_ctx.depth_data_shape,
   }
+  render_shim = _render_shim
+  num_outputs = 2
+  if with_segmentation:
+    output_dims['seg'] = render_ctx.seg_data_shape
+    render_shim = _render_with_segmentation_shim
+    num_outputs = 3
   jf = ffi.jax_callable_variadic_tuple(
-      _render_shim,
-      num_outputs=2,
+      render_shim,
+      num_outputs=num_outputs,
       output_dims=output_dims,
       vmap_method=None,
       in_out_argnames=set([]),
-      stage_in_argnames=set([
-          'cam_fovy',
-          'cam_intrinsic',
-          'cam_xmat',
-          'cam_xpos',
-          'geom_matid',
-          'geom_rgba',
-          'geom_size',
-          'geom_xmat',
-          'geom_xpos',
-          'light_castshadow',
-          'light_type',
-          'mat_rgba',
-          'mat_texid',
-      ]),
+      stage_in_argnames=_RENDER_STAGE_IN_ARGNAMES,
       stage_out_argnames=set([]),
       graph_mode=m.opt._impl.graph_mode,
       has_side_effect=False,
@@ -208,3 +303,26 @@ def render_vmap(
 ):
   out = render(m, d, ctx)
   return out, [True, True]
+
+
+@jax.custom_batching.custom_vmap
+@functools.partial(ffi.marshal_jax_warp_callable, tree_map_output=True)
+def render_with_segmentation(
+    m: types.Model,
+    d: types.Data,
+    ctx: RenderContextPytree,
+):
+  return _render_jax_impl(m, d, ctx, with_segmentation=True)
+
+
+@render_with_segmentation.def_vmap
+@functools.partial(ffi.marshal_custom_vmap, tree_map_output=True)
+def render_with_segmentation_vmap(
+    unused_axis_size,
+    is_batched,
+    m: types.Model,
+    d: types.Data,
+    ctx: RenderContextPytree,
+):
+  out = render_with_segmentation(m, d, ctx)
+  return out, [True, True, True]

mjx/mujoco/mjx/warp/render_test.py

@@ -19,22 +19,22 @@ from absl.testing import absltest
 from absl.testing import parameterized
 import jax
 from jax import numpy as jp
+import numpy as np
+
 import mujoco
 from mujoco import mjx
 from mujoco.mjx._src import bvh
 from mujoco.mjx._src import forward
 from mujoco.mjx._src import io
 from mujoco.mjx._src import render
-import mujoco.mjx.warp as mjxw
 from mujoco.mjx.warp import test_util as tu
 from mujoco.mjx.warp import warp as wp  # pylint: disable=g-importing-member
-import numpy as np
-
+import mujoco.mjx.warp as mjxw
 
 _FORCE_TEST = os.environ.get('MJX_WARP_FORCE_TEST', '0') == '1'
 
 
-def _get_model_data_rc(xml, batch_size):
+def _get_model_data_rc(xml, batch_size, render_seg=False):
   m = tu.load_test_file(xml)
   d = mujoco.MjData(m)
   mujoco.mj_forward(m, d)
@@ -63,6 +63,7 @@ def _get_model_data_rc(xml, batch_size):
       use_shadows=True,
       render_rgb=True,
       render_depth=True,
+      render_seg=render_seg,
       enabled_geom_groups=[0, 1, 2],
   )
   return mx, dx_batch, rc
@@ -148,6 +149,88 @@ class RenderTest(parameterized.TestCase):
     self.assertGreater(np.count_nonzero(depth), 0)
     self.assertNotEqual(np.unique(depth).shape[0], 1)
 
+  @parameterized.product(
+      xml=('humanoid/humanoid.xml',),
+      batch_size=(1, 16),
+  )
+  def test_render_with_segmentation(self, xml: str, batch_size: int):
+    """Tests MJX render pipeline with packed segmentation output."""
+    self._maybe_skip()
+    mx, dx_batch, rc = _get_model_data_rc(xml, batch_size, render_seg=True)
+
+    dx_batch = jax.jit(mjx.refit_bvh)(mx, dx_batch, rc.pytree())
+    out_batch = jax.jit(mjx.render_with_segmentation)(mx, dx_batch, rc.pytree())
+
+    rgb = np.asarray(out_batch[0])
+    depth = np.asarray(out_batch[1])
+    seg = np.asarray(out_batch[2])
+
+    self.assertGreater(np.count_nonzero(rgb), 0)
+    self.assertGreater(np.count_nonzero(depth), 0)
+    self.assertTrue(np.any(seg != -1))
+    self.assertGreater(np.unique(seg).shape[0], 1)
+
+    unpacked_seg = jax.vmap(mjx.get_segmentation, in_axes=(None, None, 0))(
+        rc.pytree(), 0, out_batch[2]
+    )
+    unpacked_seg = np.asarray(unpacked_seg)
+    width, height = rc._default.cam_res.numpy()[
+        0
+    ]  # pylint: disable=protected-access
+    seg_adr = int(
+        rc._default.seg_adr.numpy()[0]  # pylint: disable=protected-access
+    )
+    expected_seg = seg[:, seg_adr : seg_adr + width * height].reshape(
+        batch_size, height, width
+    )
+    np.testing.assert_array_equal(unpacked_seg, expected_seg)
+
+  @parameterized.product(
+      xml=('humanoid/humanoid.xml',),
+      batch_size=(4, 16),
+  )
+  def test_render_with_segmentation_nested_vmap(
+      self, xml: str, batch_size: int
+  ):
+    """Tests MJX render_with_segmentation with nested vmap."""
+    self._maybe_skip()
+    mx, dx_batch, rc = _get_model_data_rc(xml, batch_size, render_seg=True)
+
+    def inner(mx, dx, rc):
+      dx = jax.vmap(bvh.refit_bvh, in_axes=(None, 0, None))(mx, dx, rc)
+      out = jax.vmap(render.render_with_segmentation, in_axes=(None, 0, None))(
+          mx, dx, rc
+      )
+      return out
+
+    dx_batch = jax.vmap(bvh.refit_bvh, in_axes=(None, 0, None))(
+        mx, dx_batch, rc.pytree()
+    )
+    ref = jax.vmap(render.render_with_segmentation, in_axes=(None, 0, None))(
+        mx, dx_batch, rc.pytree()
+    )
+    ref_rgb = np.asarray(ref[0])
+    ref_depth = np.asarray(ref[1])
+    ref_seg = np.asarray(ref[2])
+
+    def _reshape_batched(x):
+      if x.shape[0] == batch_size:
+        return x.reshape(2, batch_size // 2, *x.shape[1:])
+      return x
+
+    dx_2d = jax.tree.map(_reshape_batched, dx_batch)
+
+    out_batch = jax.vmap(inner, in_axes=(None, 0, None))(mx, dx_2d, rc.pytree())
+    out_batch = jax.tree.map(lambda x: x.reshape(-1, *x.shape[2:]), out_batch)
+    rgb = np.asarray(out_batch[0])
+    depth = np.asarray(out_batch[1])
+    seg = np.asarray(out_batch[2])
+
+    np.testing.assert_array_equal(rgb, ref_rgb)
+    np.testing.assert_array_equal(depth, ref_depth)
+    np.testing.assert_array_equal(seg, ref_seg)
+    self.assertTrue(np.any(seg != -1))
+
 
 class RenderContextGarbageCollectionTest(absltest.TestCase):
   """Tests that RenderContext cleans up buffers on deletion."""