We propose an efficient framework to realistically render 3D faces with a reduced set of points. First, a robust active appearance model is presented to detect facial features in the projected faces ...under different illumination conditions. Then, an adaptive simplification of 3D faces is proposed to reduce the number of points, yet preserve the detected facial features. Finally, the point model is rendered directly, without such additional processing as parameterization of skin texture. This fully automatic framework is very effective in rendering massive facial data on mobile devices.
The increasing popularity of points as rendering primitives has led to a variety of different rendering algorithms, and the different implementations compare like apples to oranges. In this paper, we ...revisit and compare a number of recently developed point-based rendering implementations within a common testbed. Also we briefly summarize a few proposed hierarchical multiresolution point data structures and discuss their advantages. Based on a common view-dependent level-of-detail (LOD) rendering framework, we then examine different hardware accelerated point rendering algorithms. Experimental results are given with respect to performance timing and rendering quality for the different approaches. Additionally, we also compare the point-based rendering techniques to a basic triangle mesh approach.
In this paper we present an out-of-core editing system for point clouds, which allows selecting and modifying arbitrary parts of a huge point cloud interactively. We can use the selections to segment ...the point cloud, to delete points, or to render a preview of the model without the points in the selections. Furthermore, we allow for inserting points into an already existing point cloud. All operations are conducted on a rendering optimized data structure that uses the raw point cloud from a laser scanner, and no additionally created points are needed for an efficient level-of-detail (LOD) representation using this data structure. We also propose an algorithm to alleviate the artifacts when rendering a point cloud with large discrepancies in density in different areas by estimating point sizes heuristically. These estimated point sizes can be used to mimic a closed surface on the raw point cloud, also when the point cloud is composed of several raw laser scans.
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► Interactive selection of arbitrary parts of a point could using a Selection Octree. ► Inserting points to and deleting points from a rendering optimized data structure. ► A point size heuristic for estimating the splat size radii in a point-based model.
In this paper, we propose a new stochastic algorithm that supports high-quality transparent visualization of line objects and apply it to polygon edges of complex three-dimensional (3D) polygon ...models. We also apply it to realizing transparent wireframe visualization that greatly improves comprehensibility of the conventional method. In our algorithm, the line opacity is recognized as the probability that a pixel on the image plane becomes the projected line colour. Our stochastic algorithm successfully makes a depth sort of rendering primitives, which often causes rendering artefacts and a wrong depth feel in conventional non-stochastic transparent rendering, unnecessary. We demonstrate our method using 3D models of the ATLAS detector, which is the world's largest high-energy elementary particle detector at CERN laboratory (EU) and a complex car engine. We also demonstrate the transparent wireframe visualization using the simulation data, which consist of many line objects, acquired for the ATLAS detector.
Confetti: object-space point blending and splatting Pajarola, R.; Sainz, M.; Guidotti, P.
IEEE transactions on visualization and computer graphics,
2004-Sept.-Oct., 2004 Sep-Oct, 2004-09-00, 20040901, Letnik:
10, Številka:
5
Journal Article
Recenzirano
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 object-space 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 /spl alpha/-blending as well as programmable vertex and pixel-shaders.
3D Computer Graphics based on clouds of points is an alternative of interest for high quality rendering of complex scenes. For high quality graphics, the computational requirements are significantly ...higher than in the case of conventional front-end vertex processing. One of the key computations in the graphics pipeline is the projection transformation. Conventional computation of the point-based projection using current vertex processors might not be the best option for scalable, high quality 3D graphics based on point clouds. In this work we propose a new scalable method that takes advantage of the special characteristics of the point rendering model. The number of reciprocal/division computations for perspective correction is reduced, using instead more effective multiply-accumulate operations. This is done by performing a linear approximation of the reciprocal at the cost of introducing an error in the pixel value. There is a trade-off in the error introduced and the exactness of the computation (linear approximation instead of reciprocal).
In this paper a new method for high quality rendering of large LiDAR-based terrain data is presented. The visualization system upgrades previous methods of point-based rendering by detecting ...continuous surfaces and replacing them with decimated triangle meshes. High-quality visualization is retained by using render-to-texture methods to generate color textures and bump maps from original LiDAR data and applying them to the newly generated triangle meshes. This hybrid approach is able to decrease rendering times of surfaces to less than 50% with little to no difference in rendering quality. The described optimizations can be executed at run-time without interfering with user interaction.
•Point-based rendering of LiDAR with splats can be optimized using textured meshes.•High-quality textures can be generated with point-based rendering.•With textures, visualization quality is retained even with a very decimated mesh.•Optimizations using meshes and textures can be calculated at run-time.•A rendering time decrease of 20–40% can be expected for typical terrain.
Point-Based Visualization for Large Hierarchies Schulz, H.-J; Hadlak, S; Schumann, H
IEEE transactions on visualization and computer graphics,
05/2011, Letnik:
17, Številka:
5
Journal Article
Recenzirano
Space-filling layout techniques for tree representations are frequently used when the available screen space is small or the data set is large. In this paper, we propose an efficient approach to ...space-filling tree representations that uses mechanisms from the point-based rendering paradigm. We present helpful interaction techniques and visual cues that tie in with our layout. Additionally, we relate this new layout approach to common layout mechanisms and evaluate the new layout along the lines of a numerical evaluation using the measures of the Ink-Paper Ratio and overplotted%, and in a preliminary user study. The flexibility of the general approach is illustrated by several enhancements of the basic layout, as well as its usage within the context of two software frameworks from different application fields.
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