Efficient Realistic Cloud Rendering using the Volumetric Rendering Technique : Science, Digital Game Development

Sammanfattning

With high quality in graphics being demanded a lot in modern video games, realistic clouds are noexception. In many video games, it is common that its rendering implementation is based on acollection of 2D cloud-images rendered into the scene. Through previously published work, it was found that while other techniques can be more appropriate depending on the project, volumetricrendering is the highest state-of-the-art in cloud rendering. The only lacking feature of this techniqueis the performance rate, as it is a very expensive technique. Two general problems regarding theperformance rate is that either the high quality of the clouds is not applicable to real-time rendering orthe quality has been pushed back to the point where the clouds lacked accuracy or realism in shape. There are three basic objectives to the project that were forumulated so that the aim can be completed. The objectives are listed as the following to satisfy the aim: Aim: Create a cloud generator with the volumetric rendering technique Objective 1: Create a 3D engine in OpenGL that generates clouds with volumetric rendering in real-time. Objective 2: Create different scenes that increase computational cost for the computer to render. Objective 3: Arrange tests across different computers running the engine and document the results in terms of performance. The project is created using the programming language C++ and the OpenGL library in Visual Studio. The code comes from a combination of other previously made projects regarding the subject ofrendering clouds in real-time. In order to save time in the project, two projects created by FedericoVaccaro and Sébastien Hillaire were used as references in order to quickly reach a solid foundation for experimenting with the performance rate of volumetric clouds. The resulting cloud implementation contains three of many cloud types and updates in real-time. It is possible to configure the clouds in real-time and have the density, coverage, light absorption and more be altered to generate between the three different cloud types. When changing the settings for the boxcontaining the clouds, as well as coloring and changing the position of the clouds and global light, the clouds updates in real-time. To conclude the project, rendering the clouds at the goal of above 60 FPS if only limiting the resultsdown to high-end computer was somewhat successful. The clouds visually looked realistic enough inthe scene and the efforts for improving the performance rate did not affect its overall quality. The high-end computer was able to render the clouds but the low-end computer was struggling with theclouds on their own