This work aims to establish an end-to-end system for tracking of physical 3D objects for virtual reality (VR) applications. We focus on training applications requiring real-time tracking of the position of small physical objects and their reflection in VR space. Out goal is to perform object tracking in a "plug and play" manner, without using complex systems with quite large tracking devices or manually implementing object tracking. We therefore propose a system for object tracking via fiducial markers alongside a software harness, to enable fast and efficient designation of objects to be tracked and data streaming solution for end-use applications. The system utilizes AruCo, AprilTag and an original Colored Control Points based fiducial system. It allows for easy tag detection and use of object position data, which are crucial for immersive training environments based on VR and eXtended Reality (XR). We evaluate various tag sizes, detection distances, and different camera devices against the theoretical limits. In effect, we create a complete solution for implementing marker-based, real-to-virtual object position mapping for various applications.
Figure 2: Example workflow with the object detection software. Source: own elaboration
Figure 3: Tracking Configuration UI. Source: own elaboration
Figure 4
Figure 6: Block diagram of the Colored Points algorithm, illustrating the single-pass clustering and topology-based pose estimation pipeline. Source: own elaboration.
Figure 7: AprilTags detected as Unity objects. Source: own elaboration.
Figure 8: Timeline of detection rate. Note: Colored Points on Generic Webcam not included since they had 0% detection rate. Source: own elaboration.
Figure 9: Average detection rate. Source: own elaboration.
Figure 10: Maximum distance from camera for various marker sizes. Source: own elaboration.
Device
Raspberry Pi Camera Module 3
Generic WebCam
Detection Method
AprilTag (4mm)
Colored Point
AprilTag (4mm)
max. normal angle hor. dev.
≈170°
≈45°
N/A
max. normal angle ver. dev.
≈45°
≈45°
N/A
max. distance
≈46cm
≈40cm
≈15cm
high movement speed det.
YES
YES
NO
% of time detected
73.8%
79.3%
14.0%
Table 1: Video test results at 1080p. Source: own elaboration.
Device
Raspberry Pi Camera Module 3
Generic Webcam
Detection Method
AprilTag
Colored Points
AprilTag
Colored Points
stable det. at d≤25cm
≥2mm
≥1mm
≥7mm
≥4mm
stable det. at d≤50cm
≥4mm
≥2mm
≥12mm
≥5mm
Table 2: Marker Sizes for stable detection at various distance thresholds at 1080p. Source: own elaboration.
Visual object tracking follows objects across video frames, maintaining their locations and identities despite motion, occlusion, and changing appearance.
We propose BlobBoards, a fiducial marker system comprising a dense, multi-scale field of Gaussian blobs and a feature-based pipeline for joint detection, identification, and pose estimation. Each board is registered from hundreds of blob features whose dense spatial coverage constrains pose, while multiple scales preserve detectability across large changes in focal length, distance, and obliquity. Learned local descriptors are matched to the reference pattern and spatially verified, so the correspondences determine pose and certify identity. Against motion-capture ground truth, BlobBoards achieve median translation errors of 3.6-5.0 mm, reducing AprilTag's median translation error by 89% on small boards and 70% on large ones. They also produce far fewer large-rotation failures than state-of-the-art tag systems. BlobBoards achieve the highest detection rate, 80% versus 74% for AprilTag and 58% for ArUco, with the largest margin on the smallest markers. Under 50% occlusion, they still detect 69% of boards with essentially unchanged median translation error, while AprilTag and ArUco detect none. In experiments BlobBoards give state-of-the-art detection rate, pose accuracy and occlusion robustness.
Accurate 3D understanding of human hands and objects during manipulation remains a significant challenge for egocentric computer vision. Existing hand-object interaction datasets are predominantly captured in controlled studio settings, which limits both environmental diversity and the ability of models trained on such data to generalize to real-world scenarios. To address this challenge, we introduce a novel marker-less multi-camera system that allows for nearly unconstrained mobility in genuinely in-the-wild conditions, while still having the ability to generate precise 3D annotations of hands and objects. The capture system consists of a lightweight, back-mounted, multi-camera rig that is synchronized and calibrated with a user-worn VR headset. For 3D ground-truth annotation of hands and objects, we develop an ego-exo tracking pipeline and rigorously evaluate its quality. Finally, we present SHOW3D, the first large-scale dataset with 3D annotations that show hands interacting with objects in diverse real-world environments, including outdoor settings. Our approach significantly reduces the fundamental trade-off between environmental realism and accuracy of 3D annotations, which we validate with experiments on several downstream tasks. show3d-dataset.github.io
Eye tracking (ET) is a foundational technology for advanced AR/VR applications. However, training ET models for every new ET device is challenging: real data collection is costly and time-consuming, while existing synthetic data generation methods lack realism. To remove the need for additional data collection while maintaining data quality, we introduce a data-driven 3D prior that models the distribution of human eyes across diverse identities, gaze directions, and light settings. This model, which we coin GazePrior, then enables sparse-input 3D reconstruction of annotated data collected with previous ET devices, which can in turn be rendered from the cameras of any target ET device. Our approach synthesizes data with the realism, diversity and ground-truth accuracy of real data collection without its prohibitive costs. Our experiments demonstrate that ET models trained with our synthesized data outperform previous zero-shot methods, achieving higher accuracy and robustness.
Corentin Dumery, David Colmenares, Alexander Fix +3
Meta Reality Labs, Redmond, USA · EPFL, Lausanne, Switzerland · Work done during an internship at Meta