Real-Time Simulation and Visualization of Large Sea Surfaces

• Main Author: Løset, Tarjei Kvamme
• Format: Others
• Language: English
• Published: Norges teknisk-naturvitenskapelige universitet, Institutt for datateknikk og informasjonsvitenskap 2007
• Subjects: ntnudaim; SIF2 datateknikk; Komplekse datasystemer
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8805

The open ocean is the setting for enterprises that require extensive monitoring, planning and training. In the offshore industry, virtual environments have been embraced to improve such processes. The presented work focuses on real-time simulation and visualization of open seas. This implies very large water surfaces dominated by wind-driven waves, but also influenced by the presence of watercraft activity and offshore installations. The implemented system treats sea surfaces as periodic elevation fields, obtained by synthesis from statistically sampled frequency spectra. Apparent repeating structures across a surface, due to this periodic nature, are avoided by decomposing the elevation field synthesis, using two or more discrete spectra with different frequency scales. A GPU-based water solver is also included. Its implementation features a convenient input interface, which exploits hardware rasterization both for efficiency and to supply the algorithm with arbitrary data, e.g. smooth, connected deflective paths. Finally, polygonal representations of visible ocean regions are obtained using a GPU-accelerated tessellation scheme suitable for wave fields. The result is realistic, unbounded ocean surfaces with natural distributions of wind-driven waves, avoiding the artificial periodicity associated with previous similar techniques. Further, the simulation allows for superposed boat wakes and surface obstacles in regions of interest. With the proposed tessellation scheme, the visualization is economic with regards to data transfer, conforming with the goal of delivering highly interactive rendering rates.