Information
- Publication Type: Master Thesis
- Workgroup(s)/Project(s):
- Date: October 2011
- Date (Start): 8. April 2011
- First Supervisor:
Abstract
In mixed reality environments virtual content typically looks very artificial. One reason for that is because there is no consistent shading between the virtual and the real objects. Two examples are shadows and indirect illumination between the artificial and the real scene elements, which require to have information about the real world’s geometry and its materials respectively. In mixed reality interaction with real objects is a key feature. Integrating consistent shading in such a system means that the system at all times needs an up-to-date model of the scene’s geometry, its lighting and its material characteristics. The information is usually obtained as a manual pre-processing step, which is a tedious, time-consuming task and has to be re-done whenever a scene element that is not tracked changes. This poses strong limits to the widespread use of such a technique and one would like to have it done automatically. However, the automatic estimation of material characteristics of real objects using color images has always been an offline task in the literature having processing times from around 30 minutes up to several hours. In this work an interactive BRDF estimation technique is proposed, which uses the parallel power of current GPUs speeding up the running time to under half a second. One reason for the speed-up was a novel GPU K-Means implementation using MIP maps to calculate the new cluster centers on the GPU, which is often done on the CPU. The 3D geometry is also reconstructed in our technique since it is needed for indirect illumination and occlusion. We use the Microsoft Kinect sensor to acquire both, the geometry and the color images and capture the lighting environment using a fish-eye lens camera. With the algorithm presented in this thesis we have shown that real-time results are possible opening up its use in mixed reality systems in order to improve the appearance of virtual content.Additional Files and Images
Weblinks
No further information available.BibTeX
@mastersthesis{Tanzmeister_2011_I3D, title = "Interactive 3D Reconstruction and BRDF Estimation for Mixed Reality Environments", author = "Georg Tanzmeister", year = "2011", abstract = "In mixed reality environments virtual content typically looks very artificial. One reason for that is because there is no consistent shading between the virtual and the real objects. Two examples are shadows and indirect illumination between the artificial and the real scene elements, which require to have information about the real world’s geometry and its materials respectively. In mixed reality interaction with real objects is a key feature. Integrating consistent shading in such a system means that the system at all times needs an up-to-date model of the scene’s geometry, its lighting and its material characteristics. The information is usually obtained as a manual pre-processing step, which is a tedious, time-consuming task and has to be re-done whenever a scene element that is not tracked changes. This poses strong limits to the widespread use of such a technique and one would like to have it done automatically. However, the automatic estimation of material characteristics of real objects using color images has always been an offline task in the literature having processing times from around 30 minutes up to several hours. In this work an interactive BRDF estimation technique is proposed, which uses the parallel power of current GPUs speeding up the running time to under half a second. One reason for the speed-up was a novel GPU K-Means implementation using MIP maps to calculate the new cluster centers on the GPU, which is often done on the CPU. The 3D geometry is also reconstructed in our technique since it is needed for indirect illumination and occlusion. We use the Microsoft Kinect sensor to acquire both, the geometry and the color images and capture the lighting environment using a fish-eye lens camera. With the algorithm presented in this thesis we have shown that real-time results are possible opening up its use in mixed reality systems in order to improve the appearance of virtual content.", month = oct, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2011/Tanzmeister_2011_I3D/", }