A Real-time Virtual Clothes Rendering System

Online shopping for clothes is becoming more and more popular. However, the return rate of clothes remains high due to size and color issues, which leads to the development of virtual fitting. There has been a significant increase in the performance of GPUs in past decades, and this brings a great opportunity for virtual fitting.The optical property for clothes is of great importance to increase the realism in virtual fitting. This thesis presents a virtual clothes rendering system, which improves the realism by using a micro-cylinder appearance model, and takes advantages of GPUs to achieve a real-time ray tracing performance. Our appearance model constructs BSDF using two weaving directions as well as weaving patterns, to simulate the anisotropic optical property for materials like nylon, silk, and velvet. The rendering of the model is interactive due to few and intuitive parameters. We revised the shadow and the grazing-angle highlight for the model based on practical applications. Our system supports normal mapping and relief mapping to simulate wrinkles of clothes, ambient occlusion to simulate global illumination, and BTDF and recursive path tracing to simulate transparent material. Besides clothes rendering, we also present a novel hybrid rendering technique to combine body photos and virtual clothes into a dressed-up virtual image. Experimental results show that our rendering system is able to generate a dressed-up image interactively and realistically, which satisfies the needs in business environments.