The rapid increase in the performance of graphics hardware, coupled with recent improvements in its programmability, have made graphics hardware a compelling platform for computationally demanding tasks in a wide variety of application domains. In this report, we describe, summarize, and analyze the latest research in mapping general-purpose computation to graphics hardware. We begin with the technical motivations that underlie general-purpose computation on graphics processors (GPGPU) and describe the hardware and software developments that have led to the recent interest in this field. We then aim the main body of this report at two separate audiences. First, we describe the techniques used in mapping general-purpose computation to graphics hardware. We believe these techniques will be generally useful for researchers who plan to develop the next generation of GPGPU algorithms and techniques. Second, we survey and categorize the latest developments in general-purpose application development on graphics hardware. This survey should be of particular interest to researchers who are interested in using the latest GPGPU applications in their systems of interest.

/pdf/a-survey-of-general-purpose-computation-on-graphics-hardware-2phx1q9xxr.pdf

A Survey of General-Purpose Computation on Graphics Hardware

A Survey of General-Purpose Computation on Graphics Hardware.

In this paper the main problems and the available solutions are addressed for the generation of 3D models from terrestrial images. Close range photogrammetry has dealt for many years with manual or automatic image measurements for precise 3D modelling. Nowadays 3D scanners are also becoming a standard source for input data in many application areas, but image-based modelling still remains the most complete, economical, portable, flexible and widely used approach. In this paper the full pipeline is presented for 3D modelling from terrestrial image data, considering the different approaches and analysing all the steps involved.

/pdf/image-based-3d-modelling-a-review-5msqumyd5o.pdf

Image-based 3d modelling: a review

https://www.graphics.rwth-aachen.de/publication/105/points1.pdf

A survey of point-based techniques in computer graphics

This paper proposes a simple and fast operator, the "Hidden" Point Removal operator, which determines the visible points in a point cloud, as viewed from a given viewpoint. Visibility is determined without reconstructing a surface or estimating normals. It is shown that extracting the points that reside on the convex hull of a transformed point cloud, amounts to determining the visible points. This operator is general - it can be applied to point clouds at various dimensions, on both sparse and dense point clouds, and on viewpoints internal as well as external to the cloud. It is demonstrated that the operator is useful in visualizing point clouds, in view-dependent reconstruction and in shadow casting.

Direct visibility of point sets

In this paper we present sequential point trees, a data structure that allows adaptive rendering of point clouds completely on the graphics processor. Sequential point trees are based on a hierarchical point representation, but the hierarchical rendering traversal is replaced by sequential processing on the graphics processor, while the CPU is available for other tasks. Smooth transition to triangle rendering for optimized performance is integrated. We describe optimizations for backface culling and texture adaptive point selection. Finally, we discuss implementation issues and show results.

Sequential point trees

We present a technique that allows the implementation of a stack on programmable graphics hardware, using textures and fragment shaders. This development enables a whole new class of GPU algorithms, including recursive functions on complex data structures. Kd-tree traversal for ray tracing is demonstrated as an application. The traversal core was integrated into a purely GPU based photorealistic path tracing system.

Stack Implementation on Programmable Graphics Hardware.

In this paper we present a technique for simulating and rendering liquid foams. We are aiming at a functional realism that allows our simulation to be consistent with the physical effects in real liquid foam while avoiding the prohibitive computational cost of a physically accurate simulation. To this end, we have to recreate two important attributes of foam. The dynamic behaviour of the simulated foam must be based on the physics of real foam, and the characteristic interior structures of foam and their optical properties must be reproduced. We tackle these requirements by introducing a two part hybrid rendering approach. The first stage is geometric and determines the dynamic behaviour of the foam by simulating structural forces on a set of spheres, which represent the foam bubbles. In the second stage we render these spheres using a special surface shader that implicitly reconstructs the foam surfaces and performs the shading calculations. This two step approach allows us to easily integrate our technique into existing ray-tracing systems. We include images of an example animation to demonstrate the visual quality.

Simulation and Rendering of Liquid Foams.

In this contribution we present a new technique of high-light substitution. From a color image sequence, acquiredwith a hand-held camera, a so-calledlight ﬁeld is gener-ated. Additionally, a highlight mask is calculated for eachimage of the sequence. The highlight mask is then used asa conﬁdence map for the light ﬁeld. This results in colorpixel interpolations at highlight pixels, taken from imagesin whichthese pixelswerenotover-imposedbyhighlights,resulting in better images. We demonstrate the techniqueon medical endoscopic images and evaluate the results onboth, natural and synthetic data. 1. Introduction When recording color image sequences of natural scenes,highlights due to specularreﬂection may considerablydis-turb the observer. This is particularly the case when med-ical images are recorded and humid tissue is subject toinspection. For endoscopic images the problem even in-creases as light source and viewing direction are almostidentical; thereby, surfaces orthogonal to the viewing di-rection are often over-imposed to such an extent, that thephysicians can only guess the tissue at that position.In this contribution we show how highlights – as wellas other image degradations– can be removed from imagesequences when a light ﬁeld is created ﬁrst, that is subse-quently used to enhance image quality at locations, wherethe input images show defects. The light ﬁeld is a four-dimensional structure for rendering virtual color imagesfrom arbitrary positions within a certain volume.

Making the Invisible Visible: Highlight Substitution by Color Light Fields.

We show a simple and efficient way for rendering arbitrary views from so-called free-form light fields , employing a convex free form camera surface and a set of arbitrarily oriented camera planes. This way directionally varying real-world imagery can be displayed without intermediate resampling steps, and yet rendering of free form light fields can be performed as efficiently as for two-planeparameterized light fields using texture mapping graphics hardware. Comparable to sphere-based parameterizations, a single free form light field can represent all possible views of the scene without the need for multiple slabs, and it allows for relatively uniform sampling. Furthermore, we extend the rendering algorithm to account for occlusion in certain input views. We apply our method to synthetic and real-world datasets with and without additional geometric information and compare the resulting rendering performance and quality to twoplane-parameterized light field rendering.

https://domino.mpi-inf.mpg.de/intranet/ag4/ag4publ.nsf/93832a04987390a3c12567530068622d/8320de37b415569fc1256a99002e9e69/$FILE/schirmacher_2001_eff.pdf

Christian Vogelgsang

Papers

Sequential point trees

Stack Implementation on Programmable Graphics Hardware.

Simulation and Rendering of Liquid Foams.

Making the Invisible Visible: Highlight Substitution by Color Light Fields.

Efficient Free Form Light Field Rendering