Figure 1: Objects created with our system. (a) boolean operations with scanned geometry, (b) an Octopus modeled by deforming and extruding a sphere, (c) a design study for a Siggraph coffee mug created by boolean operations, free-form deformation and displacement mapping. We present a versatile and complete free-form shape modeling framework for point-sampled geometry. By combining unstructured point clouds with the implicit surface definition of the moving least squares approximation, we obtain a hybrid geometry representation that allows us to exploit the advantages of implicit and parametric surface models. Based on this representation we introduce a shape modeling system that enables the designer to perform large constrained deformations as well as boolean operations on arbitrarily shaped objects. Due to minimum consistency requirements, point-sampled surfaces can easily be re-structured on the fly to support extreme geometric deformations during interactive editing. In addition, we show that strict topology control is possible and sharp features can be generated and preserved on point-sampled objects. We demonstrate the effectiveness of our system on a large set of input models, including noisy range scans, irregular point clouds, and sparsely as well as densely sampled models.

Figure 1: Continuous detail levels of a Buddha generated in vertex programs on the GPU. The colors denote the LOD level used and the bars describe the selected amount of points selected for the GPU (top row) and the average CPU load required for rendering (bottom row). 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.

In the last years point-based rendering has been shown to offer the potential to outperform traditional triangle based rendering both in speed and visual quality when it comes to processing highly complex models. Existing surface splatting techniques achieve superior visual quality by proper filtering but they are still limited in rendering speed. On the other hand the increasing availability and programmability of graphics hardware lead to the developement of very efficient hardware-accelerated rendering methods. However, since no filtered splats are used, these approaches trade visual quality for rendering speed.

In this paper we present an algorithm to perform interactive boolean operations on free-form solids bounded by surfels. We introduce a fast inside-outside test to check whether surfels lie within the bounds of another surfel-bounded solid. This enables us to add, subtract and intersect complex solids at interactive rates. Our algorithm is fast both in displaying and constructing the new geometry resulting from the boolean operation. We present a

Numerical particle simulations and astronomical observations create huge data sets containing uncorrelated 3D points of varying size. These data sets cannot be visualized interactively by simply rendering millions of colored points for each frame. Therefore, in many visualization applications a scalar density corresponding to the point distribution is resampled on a regular grid for direct volume rendering. However, many fine details are usually lost for voxel resolutions which still allow interactive visualization on standard workstations. Since no surface geometry is associated with our data sets, the recently introduced point-based rendering algorithms cannot be applied as well.

We present 3D video fragments, a dynamic point sample framework for real-time free-viewpoint video. By generalizing 2D video pixels towards 3D irregular point samples we combine the simplicityof conventional 2D video processing with the power of more complex polygonal representations for free-viewpoint video. We propose a differential update scheme exploiting the spatio-temporal coherence of the video streams of multiple cameras. Updates are issued byoperators such as inserts and deletes accounting for changes in the input video images. The operators from multiple cameras are processed, merged into a 3D video stream and transmitted to a remote site. We also introduce a novel concept for camera control which dynamically selects the set of relevant cameras for reconstruction. Moreover, it adapts to the processing load and rendering platform. Our framework is generic in the sense that it works with anyrealtime 3D reconstruction method which extracts depth from images. The video renderer displays free-viewpoint videos using an efficient point-based splatting scheme and makes use of state-of-the-art vertex and pixel processing hardware for real-time visual processing.

We present a novel algorithm for accurate, high quality point rendering, which is based on the formulation of splatting using homogeneous coordinates. In contrast to previous methods, this leads to perspective correct splat shapes, avoiding artifacts such as holes caused by the affine approximation of the perspective projection. Further, our algorithm implements the EWA resampling filter, hence providing high image quality with anisotropic texture filtering. We also present an extension of our rendering primitive that facilitates the display of sharp edges and corners. Finally, we describe an efficient implementation of the entire point rendering pipeline using vertex and fragment programs of current GPUs.

Point-based rendering is a compact and efficient means of displaying complex geometry. Our goal is to enable flexible point-based rendering, permitting local image refinement, required for example when zooming into very complex scenes, and efficient shadow computations. We use hierarchical packed point representations, based on recursive grid data structures. Such compact structures are particularly well adapted to devices with limited memory and display resolution, such as PDA’s. To achieve flexible rendering we store intermediate attributes such as normals and colors at internal nodes of the hierarchy. We examine the memory and computation tradeoffs involved in the type of structure used, and find that tri-grids (3x3x3 hierarchical grids) are a suitable compromise for many cases. We show implementations of our method on PC and on a PDA, for octrees and tri-grids. The PDA version can render objects sampled by 1.3 million points at 2.1 frames per second. 1

Abstract—In this paper, we present Confetti, a novel point-based rendering approach based on object-space point interpolation of densely sampled surfaces. We introduce the concept of a transformation-invariant covariance matrix of a set of points which can efficiently be used to determine splat sizes in a multiresolution point hierarchy. We also analyze continuous point interpolation in objectspace and we define a new class of parameterized blending kernels as well as a normalization procedure to achieve smooth blending. Furthermore, we present a hardware accelerated rendering algorithm based on texture mapping and-blending as well as programmable vertex and pixel-shaders. Index Terms—Point-based rendering, multiresolution modeling, level-of-detail, hardware accelerated blending. 1

Using surface splats as a rendering primitive has gained increasing attention recently due to its potential for high-performance and high-quality rendering of complex geometric models. However, as with any other rendering primitive, the processing costs are still proportional to the number of primitives that we use to represent a given object. This is why complexity reduction for point-sampled geometry is as important as it is, e.g., for triangle meshes. In this paper we present a new sub-sampling technique for dense point clouds which is specifically adjusted to the particular geometric properties of circular or elliptical surface splats. A global optimization scheme computes an approximately minimal set of splats that covers the entire surface while staying below a globally prescribed maximum error tolerance #. Since our algorithm converts pure point sample data into surface splats with normal vectors and spatial extent, it can also be considered as a surface reconstruction technique which generates a hole-free piecewise linear C continuous approximation of the input data. Here we can exploit the higher flexibility of surface splats compared to triangle meshes. Compared to previous work in this area we are able to obtain significantly lower splat numbers for a given error tolerance.