Shader Programming: An Introduction Using the Effect Framework

Current commodity graphics cards offer programmability through vertex shaders and pixel shaders to create special effects by deformation, lighting, texturing, etc. The Effect framework introduced by Microsoft allows to store shader program code, settings, and a limited graphical user interface within a single .fx text file. This supports a division of labor between programmers writing the code and designers using the GUI elements to control settings. Furthermore, the Effect framework proves to be ideal for experimenting with shader programming — be it for learning purposes or for rapid prototyping. In this tutorial, we employ the Effect framework for an exploratory, hands-on approach, introducing first principles only as needed, not in advance. Simple shader programs are used to review basic 3D techniques such as homogeneous coordinates and the Phong shading model. Then we turn to basic deformation effects employing vertex shaders and the use of texture maps as decals or reflected environments inside pixel shaders. To create bump mapping and related effects, tangent space coordinates and normal maps are introduced. Finally, we treat more complex effects such as anisotropic specular highlights. Keywords: Pixel shader, Vertex shader, HLSL, Effect framewor

Programming a Music Synthesizer through Data Mining

ABSTRACT Sound libraries for music synthesizers easily comprise one thousand or more programs ("patches"). Thus, there are enough raw data to apply data mining to reveal typical settings and to extract dependencies. Intelligent user interfaces for music synthesizers can be based on such statistics. This paper proposes two approaches: First, the user sets any number of parameters and then lets the system find the nearest sounds in the database, a kind of patch autocompletion. Second, all parameters are "live" as usual, but turning one knob or setting a switch will also change the settings of other, statistically related controls. Both approaches can be used with the standard interface of the synthesizer. On top of that, this paper introduces alternative or additional interfaces based on data visualization

Digitalisierung der Hochschullehre: Was wissen wir wirklich?

Im Dickicht von Wunschvorstellungen, Marketing und schwacher Empirie fällt es oft schwer zu erkennen, auf welche Erkenntnisse sich eine digitale Unterstützung der Hochschullehre stützen kann. Dass vieles in diesem Bereich auf tönernen Füßen steht, liegt sowohl an schwachen Methoden als auch an der Tücke des Forschungsgegenstands. Dennoch lassen sich einige Erkenntnisse anführen, die als gesichert gelten können, aber Lehrende oft überraschen. Zudem stellt sich die Verknüpfung von Forschung und Praxis als Herausforderung dar: Lehrende müssen viele Fragen, auf die es weder allgemeine noch zeitlich beständige Antworten gibt, selbst, also in ihrer eigenen Praxis, lösen - unterstützt durch digitale Medien. (DIPF/Orig.

Die Internationalisierung der deutschen Hochschule im Zeichen virtueller Lehr- und Lernszenarien

Der Einsatz von offenen und kostenlosen Onlinekursen, "Massive Open Online Courses" (MOOCs) wird seit einiger Zeit an Hochschulen diskutiert. Ob MOOCs die Internationalisierung der Hochschulen befördern können, hat eine Arbeitsgruppe des DAAD thematisiert. Der Band informiert über Anfänge, Status Quo, Auswirkungen und das Internationalisierungspotenzial der virtuellen Lehr-/Lernszenarien und stellt die Ergebnisse und Schlussfolgerungen der Projektgruppe vor.Third level education institutes have been discussing the implementation of open access, free online study courses, aka "Massive Open Online Courses" (MOOCs) for quite some time. A work group of the DAAD looked at whether MOOCs could additionally promote the internationalisation of third level education institutes. The volume offers information about the starting points, status quo, effects and the internationalisation potential of virtual teaching/learning scenarios and presents the findings and conclusions of the project group

Abstrakte Räume und unterschwellige Signale. Neue Sichten auf das Phänomen "MOOC" (Visionen & Konzepte)

Bei „Lernräumen“ denkt man zunächst an Hörsäle und Bibliotheken. Was aber mehr und mehr zählt, sind medial im Internet generierte Lernräume und damit verbundene weitere Handlungsräume, die analog zu Marktplatz, Bühne und Rennstrecke funktionieren, insbesondere in den massiven offenen Online-Kursen (MOOCs). Um sich in diesen Räumen zu positionieren, senden die Akteure Signale - insbesondere sogenannte „teure Signale“ nach Art der (scheinbar) unnötig aufwändigen Federn eines Pfaus - über die Leistungsfähigkeit als Institution, Dozent oder Lerner sowie Signale über das Verständnis von Bildung. Diese Art der Betrachtung erhellt einige scheinbar paradoxe Effekte. (DIPF/Orig.

Complex water effects at interactive frame rates

Due to the complexity of the effects, it is difficult to achieve photorealism and physically correct motion in interactive 3-D water simulations. We present a simulation and visualization method which goes a long way towards physical reality, e. g. by producing Kelvin ship waves and displaying images of real caustics on the water surface. Using efficient approximations and employing the specialized 3-D and CPU features of modern PCs, this simulation runs at rates of several frames per second. Part of this solution is the emulation of a hardware accumulation buffer on consumer 3-D graphics cards with the help of texture shaders

Emulating an offline renderer by 3D graphics hardware

3D design software has since long employed graphics chips for low-quality real-time previewing. But their dramatically increased computing power now paves the way to accelerate the final high-quality rendering, too. While as yet only one major 3D software package offers a dedicated “hardware renderer” for final output, a small number of design applications can leverage the graphics card to support game creation: They display vertex and pixel shader effects in the same way as they appear on the game’s screen. We present an approach unifying the use of graphics cards for game design and for final rendering. It is implemented as a plug-in for Maxon Cinema 4D, a standard commercial software package for modelling, animation, and rendering. We examine which factors determine the performance of this solution and discuss corresponding improvements

Paving Procedural Roads with Pixel Shaders

Modern graphics hardware can be used to create procedural geometry. Our proposal details an optimized method to form roads and similar 3D objects by cookie-cutting them from slightly oversized polygons. The roads follow spline-like curves on a plane. The curves and their offset variants are cast into an approximated, implicit description. This can efficiently be evaluated within a pixel shader to discard pixels that are part of the oversized polygons but not part of the roads. Our method guarantees smooth geometry and smooth texturing. To achieve comparable results with roads formed from polygons in the usual way requires level-of-detail or similar mechanisms which not only complicate development and scene management, but also add load on the CPU