Two-phase real-time rendering method for realistic water refraction

Abstract

Background: Realistic rendering has been an important goal of several interactive applications, which requires an efficient virtual simulation of many special effects that are common in the real world. However, refraction is often ignored in these applications. Rendering the refraction effect is extremely complicated and time-consuming. Methods: In this study, a simple, efficient, and fast rendering technique of water refraction effects is proposed. This technique comprises a broad and narrow phase. In the broad phase, the water surface is considered flat. The vertices of underwater meshes are transformed based on Snell's Law. In the narrow phase, the effects of waves on the water surface are examined. Every pixel on the water surface mesh is collected by a screen-space method with an extra rendering pass. The broad phase redirects most pixels that need to be recalculated in the narrow phase to the pixels in the rendering buffer. Results: We analyzed the performances of three different conventional methods and ours in rendering refraction effects for the same scenes. The proposed method obtains higher frame rate and physical accuracy comparing with other methods. It is used in several game scene, and realistic water refraction effects can be generated efficiently. Conclusions: The two-phase water refraction method produces a tradeoff between efficiency and quality. It is easy to implementin modern game engines, and thus improve the quality of rendering scenes in video games or other real-time applications.

Keywords

• Real-time rendering
• Refraction
• Liquid rendering