From 4533b0496697574550be9c99da9df3eda8c08937 Mon Sep 17 00:00:00 2001 From: Philipp Reist Date: Tue, 9 Sep 2025 15:11:08 +0200 Subject: [PATCH 1/2] Clarifies asset classes' default_inertia frames --- .../isaaclab/assets/articulation/articulation_data.py | 5 +++-- .../isaaclab/assets/rigid_object/rigid_object_data.py | 7 +++++-- .../rigid_object_collection_data.py | 7 +++++-- 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/source/isaaclab/isaaclab/assets/articulation/articulation_data.py b/source/isaaclab/isaaclab/assets/articulation/articulation_data.py index 145a69dfc85f..99b2f76abfa2 100644 --- a/source/isaaclab/isaaclab/assets/articulation/articulation_data.py +++ b/source/isaaclab/isaaclab/assets/articulation/articulation_data.py @@ -151,8 +151,9 @@ def update(self, dt: float): default_inertia: torch.Tensor = None """Default inertia for all the bodies in the articulation. Shape is (num_instances, num_bodies, 9). - The inertia is the inertia tensor relative to the center of mass frame. The values are stored in - the order :math:`[I_{xx}, I_{xy}, I_{xz}, I_{yx}, I_{yy}, I_{yz}, I_{zx}, I_{zy}, I_{zz}]`. + The inertia tensor should be given with respect to the center of mass, expressed in the articulation links' actor frame. + The values are stored in the order :math:`[I_{xx}, I_{yx}, I_{zx}, I_{xy}, I_{yy}, I_{zy}, I_{xz}, I_{yz}, I_{zz}]`. + However, due to the symmetry of inertia tensors, row- and column-major orders are equivalent. This quantity is parsed from the USD schema at the time of initialization. """ diff --git a/source/isaaclab/isaaclab/assets/rigid_object/rigid_object_data.py b/source/isaaclab/isaaclab/assets/rigid_object/rigid_object_data.py index 3aac87d324f0..ee83900376f6 100644 --- a/source/isaaclab/isaaclab/assets/rigid_object/rigid_object_data.py +++ b/source/isaaclab/isaaclab/assets/rigid_object/rigid_object_data.py @@ -112,8 +112,11 @@ def update(self, dt: float): default_inertia: torch.Tensor = None """Default inertia tensor read from the simulation. Shape is (num_instances, 9). - The inertia is the inertia tensor relative to the center of mass frame. The values are stored in - the order :math:`[I_{xx}, I_{xy}, I_{xz}, I_{yx}, I_{yy}, I_{yz}, I_{zx}, I_{zy}, I_{zz}]`. + The inertia tensor should be given with respect to the center of mass, expressed in the rigid body's actor frame. + The values are stored in the order :math:`[I_{xx}, I_{yx}, I_{zx}, I_{xy}, I_{yy}, I_{zy}, I_{xz}, I_{yz}, I_{zz}]`. + However, due to the symmetry of inertia tensors, row- and column-major orders are equivalent. + + This quantity is parsed from the USD schema at the time of initialization. """ ## diff --git a/source/isaaclab/isaaclab/assets/rigid_object_collection/rigid_object_collection_data.py b/source/isaaclab/isaaclab/assets/rigid_object_collection/rigid_object_collection_data.py index 897679f75aa5..328010bb14f6 100644 --- a/source/isaaclab/isaaclab/assets/rigid_object_collection/rigid_object_collection_data.py +++ b/source/isaaclab/isaaclab/assets/rigid_object_collection/rigid_object_collection_data.py @@ -118,8 +118,11 @@ def update(self, dt: float): default_inertia: torch.Tensor = None """Default object inertia tensor read from the simulation. Shape is (num_instances, num_objects, 9). - The inertia is the inertia tensor relative to the center of mass frame. The values are stored in - the order :math:`[I_{xx}, I_{xy}, I_{xz}, I_{yx}, I_{yy}, I_{yz}, I_{zx}, I_{zy}, I_{zz}]`. + The inertia tensor should be given with respect to the center of mass, expressed in the rigid body's actor frame. + The values are stored in the order :math:`[I_{xx}, I_{yx}, I_{zx}, I_{xy}, I_{yy}, I_{zy}, I_{xz}, I_{yz}, I_{zz}]`. + However, due to the symmetry of inertia tensors, row- and column-major orders are equivalent. + + This quantity is parsed from the USD schema at the time of initialization. """ ## From 109d314d1fb87cdc338f7ccfd555210930d6fa5d Mon Sep 17 00:00:00 2001 From: Philipp Reist Date: Tue, 9 Sep 2025 15:26:04 +0200 Subject: [PATCH 2/2] Add myself to contributors --- CONTRIBUTORS.md | 1 + 1 file changed, 1 insertion(+) diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md index ee6200de8694..47335ecb0fbc 100644 --- a/CONTRIBUTORS.md +++ b/CONTRIBUTORS.md @@ -111,6 +111,7 @@ Guidelines for modifications: * Özhan Özen * Patrick Yin * Peter Du +* Philipp Reist * Pulkit Goyal * Qian Wan * Qinxi Yu