SharpTimeGS: Sharp and Stable Dynamic Gaussian Splatting via Lifespan Modulation

TL;DR

SharpTimeGS introduces a lifespan-aware 4D Gaussian framework for dynamic scene view synthesis, balancing static and dynamic regions to achieve stable, high-quality, real-time rendering.

Contribution

It proposes a learnable lifespan parameter and a lifespan-velocity-aware densification strategy for improved stability and dynamic fidelity in 4D Gaussian representations.

Findings

Achieves state-of-the-art performance on multiple benchmarks.

Supports real-time rendering up to 4K at 100 FPS.

Effectively balances static and dynamic regions for stable long-term reconstruction.

Abstract

Novel view synthesis of dynamic scenes is fundamental to achieving photorealistic 4D reconstruction and immersive visual experiences. Recent progress in Gaussian-based representations has significantly improved real-time rendering quality, yet existing methods still struggle to maintain a balance between long-term static and short-term dynamic regions in both representation and optimization. To address this, we present SharpTimeGS, a lifespan-aware 4D Gaussian framework that achieves temporally adaptive modeling of both static and dynamic regions under a unified representation. Specifically, we introduce a learnable lifespan parameter that reformulates temporal visibility from a Gaussian-shaped decay into a flat-top profile, allowing primitives to remain consistently active over their intended duration and avoiding redundant densification. In addition, the learned lifespan modulates each primitives' motion, reducing drift in long-lived static points while retaining unrestricted motion for short-lived dynamic ones. This effectively decouples motion magnitude from temporal duration, improving long-term stability without compromising dynamic fidelity. Moreover, we design a lifespan-velocity-aware densification strategy that mitigates optimization imbalance between static and dynamic regions by allocating more capacity to regions with pronounced motion while keeping static areas compact and stable. Extensive experiments on multiple benchmarks demonstrate that our method achieves state-of-the-art performance while supporting real-time rendering up to 4K resolution at 100 FPS on one RTX 4090.