Surface Splatting

Modern laser range and optical scanners need rendering techniques that can handle millions of points with high resolution textures. This paper describes a point rendering and texture filtering technique called surface splatting which directly renders opaque and transparent surfaces from point clouds without connectivity. It is based on a novel screen space formulation of the Elliptical Weighted Average (EWA) filter. Our rigorous mathematical analysis extends the texture resampling framework of Heckbert to irregularly spaced point samples. To render the points, we develop a surface splat primitive that implements the screen space EWA filter. Moreover, we show how to optimally sample image and procedural textures to irregular point data during pre-processing. We also compare the optimal algorithm with a more efficient view-independent EWA pre-filter. Surface splatting makes the benefits of EWA texture filtering available to point-based rendering. It provides high quality anisotropic texture filtering, hidden surface removal, edge anti-aliasing, and order-independent transparency.Engineering and Applied Science

EWA Splatting

In this paper, we present a framework for high quality splatting based on elliptical Gaussian kernels. To avoid aliasing artifacts, we introduce the concept of a resampling filter, combining a reconstruction kernel with a low-pass filter. Because of the similarity to Heckbert's EWA (elliptical weighted average) filter for texture mapping, we call our technique EWA splatting. Our framework allows us to derive EWA splat primitives for volume data and for point-sampled surface data. It provides high image quality without aliasing artifacts or excessive blurring for volume data and, additionally, features anisotropic texture filtering for point-sampled surfaces. It also handles nonspherical volume kernels efficiently; hence, it is suitable for regular, rectilinear, and irregular volume datasets. Moreover, our framework introduces a novel approach to compute the footprint function, facilitating efficient perspective projection of arbitrary elliptical kernels at very little additional cost. Finally, we show that EWA volume reconstruction kernels can be reduced to surface reconstruction kernels. This makes our splat primitive universal in rendering surface and volume data.Engineering and Applied Science

Multiresolution Ray Tracing For Point-Based Geometry [QA445. N832 2007 f rb].

Tumpuan utama di dalam tesis ini adalah kajian tentang integrasi teknik berbilang peleraian dengan penyurihan sinar di dalam menjanakan imej objek objek 3D berasas titik. The primary concern in this thesis is with the incorporation of multiresolutionbased optimization into ray tracing algorithms specially tailored for point-based geometry

Depth of field guided visualisation on light field displays

Light field displays are capable of realistic visualization of arbitrary 3D content. However, due to the finite number of light rays reproduced by the display, its bandwidth is limited in terms of angular and spatial resolution. Consequently, 3D content that falls outside of that bandwidth will cause aliasing during visualization. Therefore, a light field to be visualized must be properly preprocessed. In this thesis, we propose three methods that properly filter the parts in the input light field that would cause aliasing. First method is based on a 2D FIR circular filter that is applied over the 4D light field. Second method utilizes the structured nature of the epipolar plane images representing the light field. Third method adopts real-time multi-layer depth-of-field rendering using tiled splatting. We also establish a connection between lens parameters in the proposed depth-of-field rendering and the display’s bandwidth in order to determine the optimal blurring amount. As we prepare light field for light field displays, a stage is added to the proposed real-time rendering pipeline that simultaneously renders adjacent views. The rendering performance of the proposed methods is demonstrated on Holografika’s Holovizio 722RC projection-based light field display

Surface modeling and rendering with line segments

Master'sMASTER OF SCIENC