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Munich, Germany

Schafer H.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sussmuth J.,Friedrich - Alexander - University, Erlangen - Nuremberg | Denk C.,Realtime Technology | Stamminger M.,Friedrich - Alexander - University, Erlangen - Nuremberg
Computers and Graphics (Pergamon)

In real-time rendering, global lighting information that is too expensive to be computed on the fly is typically pre-computed and baked as vertex attributes or into textures. Prominent examples are view independent effects, such as ambient occlusion, shadows, indirect lighting, or radiance transfer coefficients. Vertex baking usually requires less memory, but exhibits artifacts on large triangles. These artifacts are avoided by baking lighting information into textures, but at the expense of significant memory consumption and additional work to obtain a parameterization. In this paper, we propose a memory efficient and performant hybrid approach that combines texture- and vertex-based baking. Cheap vertex baking is applied by default and textures are used only where vertex baking is insufficient to represent the signal. Seams at transitions between both representations are hidden using a simple shader which smoothly blends between vertex- and texture-based shading. With our fully automatic approach, we can significantly reduce memory requirements without negative impact on rendering quality or performance. © 2011 Elsevier Ltd. Source

Berger K.,TU Braunschweig | Weidlich A.,Realtime Technology | Wilkie A.,Charles University | Magnor M.,TU Braunschweig
IEEE Computer Graphics and Applications

Researchers have introduced many bidirectional reflectance distribution function (BRDF) models for computer graphics. Some are purely appearance-based heuristics, whereas others are physically plausible. To achieve plausibility, researchers have measured the reflectance of a range of material surfaces and then fit the BRDF models to these measurements. The proposed systematic approach verifies predictions of basic analytical BRDF models on the basis of measurements of real-world samples. It employs ellipsometry to verify both the actual polarizing effect and the overall reflectance behavior of metallic surfaces. © 2012 IEEE. Source

Realtime Technology | Date: 2014-11-03

Electric bulbs; Electric light bulbs; Fixtures for incandescent light bulbs; Fluorescent electric light bulbs; Fluorescent lighting tubes; Halogen light bulbs; Incandescent light bulbs; Lamp bulbs; LED and HID light fixtures; LED light bulbs; Light bulbs; Lightbulbs; Lighting fixtures that integrate natural daylight and fluorescent lighting into the fixture; Miniature light bulbs; Solar light fixtures, namely, indoor and outdoor solar powered lighting units and fixtures.

Grzegorzek M.,University of Koblenz-Landau | Paulus D.,University of Koblenz-Landau | Trierscheid M.,Realtime Technology | Trierscheid M.,Universitatsstr 3 | Papoutsis D.,Realtime Technology
Proceedings - International Conference on Image Processing, ICIP

A virtual articulator is a system currently being developed for dentistry. It is supposed to virtually determine teeth antagonists and the occlusion surfaces between them. In contrast to state-of-the-art mechanical articulators, it should use 3D dentition models acquired with highly precise 3D scanners for this. These models, however, describe not only teeth surfaces. Neighbouring surfaces such as teethridge are also included in them. Thus, the first and unavoidable step in designing a virtual articulator is the segmentation of teeth from 3D dentition models. In this paper, we present a robust solution to this problem. First, 2D sectional images of the 3D models are generated and binarised. Second, 2D teeth outlines are estimated using active contours and summarised to 3D segmentation results. The algorithm has provided excellent experimental results and will be used in the industrial realisation of the virtual articulator. © 2010 IEEE. Source

Finckh M.,Realtime Technology | Dammertz H.,Realtime Technology | Lensch H.P.A.,University of Tubingen
Computer Graphics Forum

One of the most elementary application of a lattice is the quantization of real-valued s-dimensional vectors into finite bit precision to make them representable by a digital computer. Most often, the simple s-dimensional regular grid is used for this task where each component of the vector is quantized individually. However, it is known that other lattices perform better regarding the average quantization error. A rank-1 lattices is a special type of lattice, where the lattice points can be described by a single s-dimensional generator vector. Further, the number of points inside the unit cube [0, 1) s is arbitrary and can be directly enumerated by a single one-dimensional integer value. By choosing a suitable generator vector the minimum distance between the lattice points can be maximized which, as we show, leads to a nearly optimal mean quantization error. We present methods for finding parameters for s-dimensional maximized minimum distance rank-1 lattices and further show their practical use in computer graphics applications. © 2013 The Authors Computer Graphics Forum © 2013 The Eurographics Association and John Wiley & Sons Ltd. Source

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