We propose an efficient approach for authoring dynamic and realistic waterfall scenes based on acquired video sequence. Traditional video based techniques generate new images by synthesizing 2D samples, i.e., texture sprites chosen from video sequence. However, they are limited to one fixed viewpoint and cannot provide arbitrary walkthrough into 3D scenes. Our approach extends this scheme by synthesizing dynamic 2D texture sprites and projecting them into 3D space. We first generate a set of basis texture sprites, which capture the representative appearances and motions of waterfall scenes contained in the video sequence. To model the shape and motion of a new waterfall scene, we interactively construct a set of flow lines taking account of physical principles. Along each flow line, the basis texture sprites are manipulated and animated dynamically, yielding a sequence of dynamic texture sprites in 3D space. These texture sprites are displayed using the point splatting technique which can beaccelerated efficiently by graphics hardware. By choosing varied basis texture sprites, waterfall scenes with different appearances and shapes can be conveniently simulated. The experimental results demonstrate that our approach achieves realistic effect and real-time frame rates on consumer PC platforms.

Yu Guan, Wei Chen, Lincan Zou, Long Zhang, Qunsheng Peng. Modelling and Rendering of Realistic Waterfall Scenes with Dynamic Texture Sprites. Journal of Computer Animation and Virtual Worlds (CAVW) 2006, 17(5):573-583 [PDF, 0.5MB][Video,24M]

In this paper we propose a new video-based texture synthesis approach for modeling realistic fluids. Beginning from input video clips with limited lengths, our approach employs mesh subdivision and frame re-organization to quickly generate new infinite video sequences while preserving the temporal coherence. We introduce a local refinement scheme to improve the synthesis results using graph cut algorithm, faithfully keeping the spatial coherence. Our approach allows user to edit the subdivision to control the appearances of the fluids. The experiment results show that our approach is easy to synthesize realistic spatio-temporally fluids, such as rivers, flames and fountains.

Lincan Zou, Dabin Li, Yu Guan, Wei Chen, Qunsheng Peng. A New Video Texture Based Fluid Modeling Approach. Chinagraph'2006 / Journal of Image and Graphics (Supplement), 2006, 6, 11:155-160. (In Chinese) [PDF, 0.5MB]

This paper presents a new algorithm for simulating waterfall animation based on the particle system and physical dynamics principle. To accelerate the collision detection between particles and scene objects, we propose to build a hierarchical bounding box for scene objects as a pretreatment. During the animation of particles, they are clustered on-the-fly as cluster trees. The hierarchical bounding box and cluster trees are used to detect the collision of between particles and scene objects, through which better performance is achieved. We show how to accomplish the rendering of particles by line based rendering technique. Furthermore, the fading effect is simulated by means of a gradual thinning and syncretizing technique. Experimental results show that our algorithm achieves real-time simulation to both the animation and appearance of waterfall in consumer PC platform.

Yu Guan, Lincan Zou, Wei Chen, Qunsheng Peng. Particle System Based Real Time Waterfall Simulation. Chinagraph'2004 / Journal of System Simulation, 2004 16(11): 2471-2474. (In Chinese) [PDF, 89KB]