Collision Mesh Schema Additions

CONTRIBUTORS.md

@@ -53,6 +53,7 @@ Guidelines for modifications:
 * Gary Lvov
 * Giulio Romualdi
 * Haoran Zhou
+* Harsh Patel
 * HoJin Jeon
 * Hongwei Xiong
 * Hongyu Li

source/isaaclab/isaaclab/sim/converters/mesh_converter.py

@@ -122,14 +122,15 @@ def _convert_asset(self, cfg: MeshConverterCfg):
             if child_mesh_prim.GetTypeName() == "Mesh":
                 # Apply collider properties to mesh
                 if cfg.collision_props is not None:
-                    # -- Collision approximation to mesh
-                    # TODO: Move this to a new Schema: https://github.com/isaac-orbit/IsaacLab/issues/163
-                    mesh_collision_api = UsdPhysics.MeshCollisionAPI.Apply(child_mesh_prim)
-                    mesh_collision_api.GetApproximationAttr().Set(cfg.collision_approximation)
                     # -- Collider properties such as offset, scale, etc.
                     schemas.define_collision_properties(
                         prim_path=child_mesh_prim.GetPath(), cfg=cfg.collision_props, stage=stage
                     )
+                # Add collision mesh
+                if cfg.mesh_collision_props is not None:
+                    schemas.define_mesh_collision_properties(
+                        prim_path=child_mesh_prim.GetPath(), cfg=cfg.mesh_collision_props, stage=stage
+                    )
         # Delete the old Xform and make the new Xform the default prim
         stage.SetDefaultPrim(xform_prim)
         # Apply default Xform rotation to mesh -> enable to set rotation and scale

source/isaaclab/isaaclab/sim/converters/mesh_converter_cfg.py

@@ -12,35 +12,30 @@
 class MeshConverterCfg(AssetConverterBaseCfg):
     """The configuration class for MeshConverter."""
 
-    mass_props: schemas_cfg.MassPropertiesCfg | None = None
+    mass_props: schemas_cfg.MassPropertiesCfg = None
     """Mass properties to apply to the USD. Defaults to None.
 
     Note:
         If None, then no mass properties will be added.
     """
 
-    rigid_props: schemas_cfg.RigidBodyPropertiesCfg | None = None
+    rigid_props: schemas_cfg.RigidBodyPropertiesCfg = None
     """Rigid body properties to apply to the USD. Defaults to None.
 
     Note:
         If None, then no rigid body properties will be added.
     """
 
-    collision_props: schemas_cfg.CollisionPropertiesCfg | None = None
+    collision_props: schemas_cfg.CollisionPropertiesCfg = None
     """Collision properties to apply to the USD. Defaults to None.
 
     Note:
         If None, then no collision properties will be added.
     """
-
-    collision_approximation: str = "convexDecomposition"
-    """Collision approximation method to use. Defaults to "convexDecomposition".
-
-    Valid options are:
-    "convexDecomposition", "convexHull", "boundingCube",
-    "boundingSphere", "meshSimplification", or "none"
-
-    "none" causes no collision mesh to be added.
+    mesh_collision_props: schemas_cfg.MeshCollisionPropertiesCfg = None
+    """Mesh approximation properties to apply to all collision meshes in the USD.
+    Note:
+        If None, then no mesh approximation properties will be added.
     """
 
     translation: tuple[float, float, float] = (0.0, 0.0, 0.0)

source/isaaclab/isaaclab/sim/schemas/__init__.py

@@ -33,26 +33,79 @@
 """
 
 from .schemas import (
+    PHYSX_MESH_COLLISION_CFGS,
+    USD_MESH_COLLISION_CFGS,
     activate_contact_sensors,
     define_articulation_root_properties,
     define_collision_properties,
     define_deformable_body_properties,
     define_mass_properties,
+    define_mesh_collision_properties,
     define_rigid_body_properties,
     modify_articulation_root_properties,
     modify_collision_properties,
     modify_deformable_body_properties,
     modify_fixed_tendon_properties,
     modify_joint_drive_properties,
     modify_mass_properties,
+    modify_mesh_collision_properties,
     modify_rigid_body_properties,
 )
 from .schemas_cfg import (
     ArticulationRootPropertiesCfg,
+    BoundingCubePropertiesCfg,
+    BoundingSpherePropertiesCfg,
     CollisionPropertiesCfg,
+    ConvexDecompositionPropertiesCfg,
+    ConvexHullPropertiesCfg,
     DeformableBodyPropertiesCfg,
     FixedTendonPropertiesCfg,
     JointDrivePropertiesCfg,
     MassPropertiesCfg,
+    MeshCollisionPropertiesCfg,
     RigidBodyPropertiesCfg,
+    SDFMeshPropertiesCfg,
+    TriangleMeshPropertiesCfg,
+    TriangleMeshSimplificationPropertiesCfg,
 )
+
+__all__ = [
+    # articulation root
+    "ArticulationRootPropertiesCfg",
+    "define_articulation_root_properties",
+    "modify_articulation_root_properties",
+    # rigid bodies
+    "RigidBodyPropertiesCfg",
+    "define_rigid_body_properties",
+    "modify_rigid_body_properties",
+    "activate_contact_sensors",
+    # colliders
+    "CollisionPropertiesCfg",
+    "define_collision_properties",
+    "modify_collision_properties",
+    # mass
+    "MassPropertiesCfg",
+    "define_mass_properties",
+    "modify_mass_properties",
+    # mesh colliders
+    "MeshCollisionPropertiesCfg",
+    "define_mesh_collision_properties",
+    "modify_mesh_collision_properties",
+    # bounding cube
+    "BoundingCubePropertiesCfg",
+    # bounding sphere
+    "BoundingSpherePropertiesCfg",
+    # convex decomposition
+    "ConvexDecompositionPropertiesCfg",
+    # convex hull
+    "ConvexHullPropertiesCfg",
+    # sdf mesh
+    "SDFMeshPropertiesCfg",
+    # triangle mesh
+    "TriangleMeshPropertiesCfg",
+    # triangle mesh simplification
+    "TriangleMeshSimplificationPropertiesCfg",
+    # Constants for configs that use PhysX vs USD API
+    "PHYSX_MESH_COLLISION_CFGS",
+    "USD_MESH_COLLISION_CFGS",
+]

source/isaaclab/isaaclab/sim/schemas/schemas.py

@@ -26,6 +26,22 @@
 Articulation root properties.
 """
 
+PHYSX_MESH_COLLISION_CFGS = [
+    schemas_cfg.ConvexDecompositionPropertiesCfg,
+    schemas_cfg.ConvexHullPropertiesCfg,
+    schemas_cfg.TriangleMeshPropertiesCfg,
+    schemas_cfg.TriangleMeshSimplificationPropertiesCfg,
+    schemas_cfg.SDFMeshPropertiesCfg,
+]
+
+USD_MESH_COLLISION_CFGS = [
+    schemas_cfg.BoundingCubePropertiesCfg,
+    schemas_cfg.BoundingSpherePropertiesCfg,
+    schemas_cfg.ConvexDecompositionPropertiesCfg,
+    schemas_cfg.ConvexHullPropertiesCfg,
+    schemas_cfg.TriangleMeshSimplificationPropertiesCfg,
+]
+
 
 def define_articulation_root_properties(
     prim_path: str, cfg: schemas_cfg.ArticulationRootPropertiesCfg, stage: Usd.Stage | None = None
@@ -851,3 +867,121 @@ def modify_deformable_body_properties(
 
     # success
     return True
+
+
+"""
+Collision mesh properties.
+"""
+
+
+def extract_mesh_collision_api_and_attrs(cfg):
+    # We use the number of user set attributes outside of the API function
+    # to determine which API to use in ambiguous cases, so collect them here
+    custom_attrs = {
+        key: value
+        for key, value in cfg.to_dict().items()
+        if value is not None and key not in ["usd_func", "physx_func"]
+    }
+
+    use_usd_api = False
+    use_phsyx_api = False
+
+    # We have some custom attributes and allow them
+    if len(custom_attrs) > 0 and type(cfg) in PHYSX_MESH_COLLISION_CFGS:
+        use_phsyx_api = True
+    # We have no custom attributes
+    elif len(custom_attrs) == 0:
+        if type(cfg) in USD_MESH_COLLISION_CFGS:
+            # Use the USD API
+            use_usd_api = True
+        else:
+            # Use the PhysX API
+            use_phsyx_api = True
+
+    elif len(custom_attrs > 0) and type(cfg) in USD_MESH_COLLISION_CFGS:
+        raise ValueError("Args are specified but the USD Mesh API doesn't support them!")
+
+    mesh_collision_appx_type = type(cfg).__name__.partition("PropertiesCfg")[0]
+
+    if use_usd_api:
+        # Add approximation to the attributes as this is how USD collision mesh API is configured
+        api_func = cfg.usd_func
+        # Approximation needs to be formatted with camelCase
+        custom_attrs["Approximation"] = mesh_collision_appx_type[0].lower() + mesh_collision_appx_type[1:]
+    elif use_phsyx_api:
+        api_func = cfg.physx_func
+    else:
+        raise ValueError("Either USD or PhysX API should be used for mesh collision approximation!")
+
+    return api_func, custom_attrs
+
+
+def define_mesh_collision_properties(
+    prim_path: str, cfg: schemas_cfg.MeshCollisionPropertiesCfg, stage: Usd.Stage | None = None
+):
+    """Apply the mesh collision schema on the input prim and set its properties.
+    See :func:`modify_collision_mesh_properties` for more details on how the properties are set.
+    Args:
+        prim_path : The prim path where to apply the mesh collision schema.
+        cfg : The configuration for the mesh collision properties.
+        stage : The stage where to find the prim. Defaults to None, in which case the
+            current stage is used.
+    Raises:
+        ValueError: When the prim path is not valid.
+    """
+    # obtain stage
+    if stage is None:
+        stage = stage_utils.get_current_stage()
+    # get USD prim
+    prim = stage.GetPrimAtPath(prim_path)
+    # check if prim path is valid
+    if not prim.IsValid():
+        raise ValueError(f"Prim path '{prim_path}' is not valid.")
+
+    api_func, _ = extract_mesh_collision_api_and_attrs(cfg=cfg)
+
+    # Only enable if not already enabled
+    if not api_func(prim):
+        api_func.Apply(prim)
+
+    modify_mesh_collision_properties(prim_path=prim_path, cfg=cfg, stage=stage)
+
+
+@apply_nested
+def modify_mesh_collision_properties(
+    prim_path: str, cfg: schemas_cfg.MeshCollisionPropertiesCfg, stage: Usd.Stage | None = None
+):
+    """Set properties for the mesh collision of a prim.
+    These properties are based on either the `Phsyx the `UsdPhysics.MeshCollisionAPI` schema.
+    .. note::
+        This function is decorated with :func:`apply_nested` that sets the properties to all the prims
+        (that have the schema applied on them) under the input prim path.
+    .. UsdPhysics.MeshCollisionAPI: https://openusd.org/release/api/class_usd_physics_mesh_collision_a_p_i.html
+    Args:
+        prim_path : The prim path of the rigid body. This prim should be a Mesh prim.
+        cfg : The configuration for the mesh collision properties.
+        stage : The stage where to find the prim. Defaults to None, in which case the
+            current stage is used.
+    """
+    # obtain stage
+    if stage is None:
+        stage = stage_utils.get_current_stage()
+    # get USD prim
+    prim = stage.GetPrimAtPath(prim_path)
+
+    api_func, custom_attrs = extract_mesh_collision_api_and_attrs(cfg=cfg)
+
+    # retrieve the mesh collision API
+    mesh_collision_api = api_func(prim)
+
+    # set custom attributes into mesh collision API
+    for attr_name, value in custom_attrs.items():
+        # Only "Attribute" attr should be in format "boundingSphere", so set camel_case to be False
+        if attr_name == "Attribute":
+            camel_case = False
+        else:
+            camel_case = True
+        safe_set_attribute_on_usd_schema(mesh_collision_api, attr_name, value, camel_case=camel_case)
+
+    # success
+    return True