Shaowei Liu

Shaowei Liu is a Research Scientist with NVIDIA Research’s Fundamental Generative AI Research Group. He received his Ph.D. in Computer Science from the University of Illinois Urbana-Champaign, advised by Prof. Shenlong Wang and Prof. Saurabh Gupta. Prior to that, he received his M.S. in Computer Science from UC San Diego, advised by Prof. Xiaolong Wang, and his B.S. in Electronic Engineering from Tsinghua University. His research focuses on video generation, and dynamic world modeling.

Symphony: Orchestrating Sparse and Dense Tensors with Hierarchical Heterogeneous Processing

Sparse tensor algorithms are becoming widespread, particularly in the domains of deep learning, graph and data analytics, and scientific computing. Current high-performance broad-domain architectures, such as GPUs, often suffer memory system inefficiencies by moving too much data or moving it too far through the memory hierarchy.

FusionRelight: Relighting Portraits in Real Time via Hybrid Domain Knowledge Fusion

Portrait relighting is a low-level vision problem in which physically plausible illumination transfer, identity preservation, and compact real-time inference must be considered together. Iterative diffusion-style methods can synthesize fine detail, but stochastic inference and cost complicate deterministic live video creation; physically grounded relighting preserves identity, but controlled synthetic or light-stage supervision transfers poorly to unconstrained cameras.

HorizonRelight: Relighting Long-horizon Videos Consistently via Diffusion Transformers

Diffusion-based video relighting enables controllable relighting from a single input video, but modern video diffusion backbones are trained on short clips and applied to long-horizon videos through chunked sliding-window inference, often causing temporal discontinuities at chunk boundaries. We address this by treating long-horizon relighting as a temporally conditioned latent-domain translation problem. Our framework enforces cross-chunk continuity by propagating target-domain latents across boundaries.

NVIDIA OmniDreams: Real-Time Generative World Model for Closed-Loop Autonomous Vehicle Simulation

As autonomous vehicle capabilities advance, the safe evaluation of driving policies in long-tail scenarios remains a critical bottleneck. In closed-loop simulation, the driving policy model actively interacts with the environment, where its actions dynamically update the simulator state and directly influence the next set of generated sensor observations. While recent reconstruction-based neural simulators offer photorealism, they are fundamentally constrained by their initial captured data and struggle to generalize to highly dynamic or novel scenes.

Training Data Attribution via Approximate Unrolling

Many training data attribution (TDA) methods aim to estimate how a model's behavior would change if one or more data points were removed from the training set. Methods based on implicit differentiation, such as influence functions, can be made computationally efficient, but fail to account for underspecification, the implicit bias of the optimization algorithm, or multi-stage training pipelines. By contrast, methods based on unrolling address these issues but face scalability challenges.

Using Large Language Models for Hyperparameter Optimization

This paper explores the use of foundational large language models (LLMs) in hyperparameter optimization (HPO). Hyperparameters are critical in determining the effectiveness of machine learning models, yet their optimization often relies on manual approaches in limited-budget settings. By prompting LLMs with dataset and model descriptions, we develop a methodology where LLMs suggest hyperparameter configurations, which are iteratively refined based on model performance.