closest point
Learning rigid-body simulators over implicit shapes for large-scale scenes and vision
Simulating large scenes with many rigid objects is crucial for a variety of applications, such as robotics, engineering, film and video games. Rigid interactions are notoriously hard to model: small changes to the initial state or the simulation parameters can lead to large changes in the final state.
- North America > United States > New Hampshire > Grafton County > Hanover (0.04)
- North America > United States > Nevada (0.04)
- Asia > Afghanistan > Parwan Province > Charikar (0.04)
NASA Finally Weighs In on the Origin of 3I/ATLAS
After weeks of silence, NASA has officially dismissed speculation that 3I/ATLAS has anything to do with aliens. After the temporary shutdown of the US government, NASA has finally started its nonessential work back up. It's starting off with a bang: The agency called a press conference to show its hitherto reserved images of the interstellar object 3I/ATLAS. NASA scientists also confirmed that 3I/ATLAS is in fact a comet, contrary to the speculations about alien technology flooding the internet. During the broadcast, a panel of scientists showed the results of observations obtained by different NASA missions across various points in the journey 3I/ATLAS has taken .
- Asia > Nepal (0.15)
- South America > French Guiana > Guyane > Cayenne (0.05)
- North America > United States > California (0.05)
- (2 more...)
- Government > Space Agency (1.00)
- Government > Regional Government > North America Government > United States Government (1.00)
The First Radio Signal From Comet 3I/Atlas Ends the Debate About Its Nature
An observatory detected the first radio signal from the interstellar object 3I/Atlas. An image of the interstellar comet 3I/Atlas, captured by the Hubble telescope on July 21, 2025. More evidence has emerged to support the natural origin of comet 3I/Atlas . After several weeks of conspiracy theories, social media debates, and speculation on popular podcasts such as Joe Rogan's, this interstellar object is still a comet . The most recent confirmation came from an observatory in South Africa that detected the first radio signal from 3I/Atlas.
- Africa > South Africa (0.25)
- Asia > Nepal (0.15)
- Asia > Middle East > Israel (0.05)
- (4 more...)
- Media (0.73)
- Leisure & Entertainment (0.72)
- Health & Medicine > Therapeutic Area > Cardiology/Vascular Diseases (0.49)
Learning rigid-body simulators over implicit shapes for large-scale scenes and vision
Simulating large scenes with many rigid objects is crucial for a variety of applications, such as robotics, engineering, film and video games. Rigid interactions are notoriously hard to model: small changes to the initial state or the simulation parameters can lead to large changes in the final state.
Segmented Trajectory Optimization for Autonomous Parking in Unstructured Environments
This paper presents a Segmented Trajectory Optimization (STO) method for autonomous parking, which refines an initial trajectory into a dynamically feasible and collision-free one using an iterative SQP-based approach. STO maintains the maneuver strategy of the high-level global planner while allowing curvature discontinuities at switching points to improve maneuver efficiency. To ensure safety, a convex corridor is constructed via GJK-accelerated ellipse shrinking and expansion, serving as safety constraints in each iteration. Numerical simulations in perpendicular and reverse-angled parking scenarios demonstrate that STO enhances maneuver efficiency while ensuring safety. Moreover, computational performance confirms its practicality for real-world applications.
- Europe > Germany > Berlin (0.04)
- Asia > Middle East > Republic of Türkiye > Karaman Province > Karaman (0.04)
- Asia > China (0.04)
- North America > United States > New Hampshire > Grafton County > Hanover (0.04)
- North America > United States > Nevada > Clark County > Las Vegas (0.04)
- Asia > Afghanistan > Parwan Province > Charikar (0.04)
Implementation and Assessment of an Augmented Training Curriculum for Surgical Robotics
Rota, Alberto, Fan, Ke, De Momi, Elena
--The integration of high-level assistance algorithms in surgical robotics training curricula may be beneficial in establishing a more comprehensive and robust skillset for aspiring surgeons, improving their clinical performance as a consequence. This work presents the development and validation of a haptic-enhanced Virtual Reality simulator for surgical robotics training, featuring 8 surgical tasks that the trainee can interact with thanks to the embedded physics engine. This virtual simulated environment is augmented by the introduction of high-level haptic interfaces for robotic assistance that aim at re-directing the motion of the trainee's hands and wrists toward targets or away from obstacles, and providing a quantitative performance score after the execution of each training exercise. An experimental study shows that the introduction of enhanced robotic assistance into a surgical robotics training curriculum improves performance during the training process and, crucially, promotes the transfer of the acquired skills to an unassisted surgical scenario, like the clinical one. The increase of surgical robotics procedures in the last decade demands a high number of trained surgeons [1] [2], capable of teleoperating such advanced and complex systems and at the same time able to take advantage of the benefits of Robot-Assisted Minimally Invasive Surgery (RAMIS) safely and effectively.
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- Instructional Material > Course Syllabus & Notes (1.00)
- Health & Medicine > Therapeutic Area (1.00)
- Health & Medicine > Surgery (1.00)
- Health & Medicine > Health Care Technology (1.00)
- Education (1.00)
From Movement Primitives to Distance Fields to Dynamical Systems
Developing autonomous robots capable of learning and reproducing complex motions from demonstrations remains a fundamental challenge in robotics. On the one hand, movement primitives (MPs) provide a compact and modular representation of continuous trajectories. On the other hand, autonomous systems provide control policies that are time independent. We propose in this paper a simple and flexible approach that gathers the advantages of both representations by transforming MPs into autonomous systems. The key idea is to transform the explicit representation of a trajectory as an implicit shape encoded as a distance field. This conversion from a time-dependent motion to a spatial representation enables the definition of an autonomous dynamical system with modular reactions to perturbation. Asymptotic stability guarantees are provided by using Bernstein basis functions in the MPs, representing trajectories as concatenated quadratic Bézier curves, which provide an analytical method for computing distance fields. This approach bridges conventional MPs with distance fields, ensuring smooth and precise motion encoding, while maintaining a continuous spatial representation. By simply leveraging the analytic gradients of the curve and its distance field, a stable dynamical system can be computed to reproduce the demonstrated trajectories while handling perturbations, without requiring a model of the dynamical system to be estimated. Numerical simulations and real-world robotic experiments validate our method's ability to encode complex motion patterns while ensuring trajectory stability, together with the flexibility of designing the desired reaction to perturbations. An interactive project page demonstrating our approach is available at https://mp-df-ds.github.io/.
Shallow Signed Distance Functions for Kinematic Collision Bodies
Akar, Osman, Han, Yushan, Chen, Yizhou, Lan, Weixian, Gallagher, Benn, Fedkiw, Ronald, Teran, Joseph
We present learning-based implicit shape representations designed for real-time avatar collision queries arising in the simulation of clothing. Signed distance functions (SDFs) have been used for such queries for many years due to their computational efficiency. Recently deep neural networks have been used for implicit shape representations (DeepSDFs) due to their ability to represent multiple shapes with modest memory requirements compared to traditional representations over dense grids. However, the computational expense of DeepSDFs prevents their use in real-time clothing simulation applications. We design a learning-based representation of SDFs for human avatars whoes bodies change shape kinematically due to joint-based skinning. Rather than using a single DeepSDF for the entire avatar, we use a collection of extremely computationally efficient (shallow) neural networks that represent localized deformations arising from changes in body shape induced by the variation of a single joint. This requires a stitching process to combine each shallow SDF in the collection together into one SDF representing the signed closest distance to the boundary of the entire body. To achieve this we augment each shallow SDF with an additional output that resolves whether or not the individual shallow SDF value is referring to a closest point on the boundary of the body, or to a point on the interior of the body (but on the boundary of the individual shallow SDF). Our model is extremely fast and accurate and we demonstrate its applicability with real-time simulation of garments driven by animated characters.
- North America > United States > New York > New York County > New York City (0.04)
- North America > United States > California > Santa Clara County > Palo Alto (0.04)
- Asia (0.04)