3D Visual Communications

4.1 3D Scene Modeling and Creation

In general, 3D scene modeling and representation approaches can be classified into three categories: geometry-based modeling, image-based modeling, and hybrid modeling which combines the geometry-based and image-based modeling in some way to represent a 3D scene at better storage cost or with better precision. Geometry-based modeling represents the scene using pure 3D computer graphics components, for example, 3D meshes or other means to represent 3D surfaces, texture maps, object material properties such as opacity, reflectance, and so on, and environment properties, such as lighting models, with the purpose of enhancing the realism of the models. Image-based modeling goes to the other extreme, using no 3D geometry, but rather using a set of images captured by a number of cameras with predesigned positions and settings. This approach tends to generate high quality virtual view synthesis without the effort of 3D scene reconstruction, and typically the synthesis quality increases with the availability of more views. The challenge for this approach is that a tremendous amount of image data needs to be stored, transferred, and processed in order to achieve a good quality synthesized view, otherwise interpolation and occlusion artifacts will appear in the synthesized image due to lack of source data. The hybrid approach can leverage these two representation methods to find a compromise between the two extremes according to given constraints; for example, ...