TSDF surface appears on unexpected face of the cube (possibly extrinsic matrix issue)

[Eunsunggcu]

Hi, I'm trying to use Open3D's TSDF integration module.
I wrote a script based on the official example to integrate a depth image into a TSDF volume.

Code snippet:

from isaacsim import SimulationApp

simulation_app = SimulationApp({"headless": False})

import isaacsim.core.utils.numpy.rotations as rot_utils
import numpy as np
import torch
from isaacsim.core.api import World
from isaacsim.core.api.objects import DynamicCuboid
from omni.isaac.core.objects import GroundPlane
from actpermoma.utils.visualisation_utils import Visualizer
from isaacsim.sensors.camera import Camera

try:
    from vgn.perception import UniformTSDFVolume
    from robot_helpers.perception import CameraIntrinsic
    from robot_helpers.spatial import Transform
except ImportError:
    simulation_app.close()
    exit()

from isaacsim.core.api.objects.sphere import VisualSphere
from pxr import UsdGeom
import omni.usd
from matplotlib import pyplot as plt


my_world = World(stage_units_in_meters=1.0)
ground_plane = GroundPlane(prim_path="/World/groundPlane", name="ground_plane", z_position=0)
my_world.scene.add(ground_plane)

my_world.scene.add(
    DynamicCuboid(
        prim_path="/World/target_cube_2",
        name="target_cube_2",
        position=np.array([0.0, 0.0, 0.0]),
        scale=np.array([0.5, 0.5, 0.25]),
        size=1.0,
        color=np.array([0, 0, 255])
    )
)

camera = Camera(
    prim_path="/World/camera",
    position=np.array([0.0, 0.0, 1.4]),
    frequency=20,
    resolution=(256, 256),
    orientation=rot_utils.euler_angles_to_quats(np.array([0, 90, 0]), degrees=True),
)
my_world.scene.add_default_ground_plane()
my_world.reset()
camera.initialize()
camera.add_distance_to_image_plane_to_frame()
visualizer = Visualizer()

length = 5.0
resolution = 100
tsdf = UniformTSDFVolume(length=length, resolution=resolution)
print(f"TSDF Volume created: {length}m length, {resolution} resolution, {tsdf.voxel_size * 1000:.1f}mm voxel size.")

MAX_POINTS = 1000

stage = omni.usd.get_context().get_stage()

i = 0
last_used_spheres = 0
reset_needed = False
while simulation_app.is_running():
    my_world.step(render=True)

    if i % 50 == 0 and i > 0:
        print(f"================================= Frame {i} =================================")
        rgba_data = camera.get_rgba()
        depth_data = camera.get_depth()

        if depth_data is not None:

            depth_image = depth_data.copy()
            depth_image[np.isinf(depth_image)] = 0.0
            depth_image = depth_image.astype(np.float32)

            width, height = camera.get_resolution()
            intrinsic_matrix = camera.get_intrinsics_matrix()
            fx, fy = intrinsic_matrix[0, 0], intrinsic_matrix[1, 1]
            cx, cy = intrinsic_matrix[0, 2], intrinsic_matrix[1, 2]
            camera_intrinsics_obj = CameraIntrinsic(width, height, fx, fy, cx, cy)

            cam_pos, cam_rot_quat = camera.get_world_pose()
            extrinsic_matrix = np.eye(4)
            extrinsic_matrix[:3, :3] = rot_utils.quats_to_rot_matrices(cam_rot_quat[np.newaxis, :])[0]
            extrinsic_matrix[:3, 3] = cam_pos
            extrinsic_transform = Transform.from_matrix(extrinsic_matrix)

            tsdf.integrate(depth_image, camera_intrinsics_obj, extrinsic_transform)
            print("TSDF volume integrated.")

            scene_cloud = tsdf.get_scene_cloud()
            points_world = np.asarray(scene_cloud.points)
            print(f"TSDF contains {points_world.shape[0]} points in world coordinates.")

            num_points_to_show = min(points_world.shape[0], MAX_POINTS)

            visualizer.draw_voxels_from_center(pcl = points_world[:num_points_to_show],voxel_size = tsdf.voxel_size)

    if my_world.is_stopped() and not reset_needed:
        reset_needed = True

    i += 1

simulation_app.close()

I expected the TSDF surface to appear on the top face of the cube in the scene, but instead, it shows up on an unexpected face, as shown in the attached image.

What I suspect:

I think I might be misusing the extrinsic matrix when calling integrate.
I assumed that if the camera's extrinsic matrix is correctly defined, the TSDF should be integrated on the correct surface — in this case, the top face of the cube.

[vick-yu]

Are you seeing this issue with version 5.0?
How did you install the actpermoma package?
Could you please provide the detailed steps you followed, so I can try to reproduce the issue on my end?