Image Quality-Driven Level of Detail Selection on a Triangle Budget

Sammanfattning: Background. Level of detail is an optimization technique used by several modern games. The level of detail systems uses simplified triangular meshes to determine the optimal combinations of 3D-models to use in order to meet a user-defined criterion for achieving fast performance. Prior work has also pre-computed level of detail settings to only apply the most optimal settings for any given view in a 3D scene. Objectives. The aim of this thesis is to determine the difference in image quality between a custom level of detail pre-preprocessing approach proposed in this paper, and the level of detail system built in the game engine Unity. This is investigated by implementing a framework in Unity for the proposed level of detail pre-preprocessing approach in this paper and designing representative test scenes to collect all data samples. Once the data is collected, the image quality produced by the proposed level of detail pre-preprocessing approach is compared to Unity's existing level of detail approach using perceptual-based metrics. Methods. The method used is an experiment. Unity's method was chosen because of the popularity of the engine, and it was decided to implement the proposed level of detail pre-preprocessing approach also in Unity to have the most fair comparison with Unity's implementation. The two approaches will only differ in how the level of detail is selected, the rest of the rendering pipeline will be exactly the same. Results. The pre-preprocessing time ranged between 13 to 30 hours. The results showed only a small difference in image quality between the two approaches, Unity's built-in system provides a better overall image quality in two out of three test scenes. Conclusions. Due to the pre-processing time and no overall improvement, it was concluded that the proposed level of detail pre-preprocessing approach is not feasible.