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Volume Ray Casting
Volume ray casting, sometimes called volumetric ray casting, volumetric ray tracing, or volume ray marching, is an image-based volume rendering technique. It computes 2D images from 3D volumetric data sets (3D scalar fields). Volume ray casting, which processes volume data, must not be mistaken with ray casting in the sense used in ray tracing, which processes surface data. In the volumetric variant, the computation doesn't stop at the surface but "pushes through" the object, sampling the object along the ray. Unlike ray tracing, volume ray casting does not spawn secondary rays. When the context/application is clear, some authors simply call it ''ray casting''. Because ray marching does not necessarily require an exact solution to ray intersection and collisions, it is suitable for real time computing for many applications for which ray tracing is unsuitable. Classification The technique of volume ray casting can be derived directly from the rendering equation. It provides re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Order
In computer graphics, image order algorithms iterate over the pixels in the image to be produced, rather than the elements in the scene to be rendered. Object order algorithms are those that iterate over the elements in the scene to be rendered, rather than the pixels in the image to be produced. For typical rendering applications, the scene contains many fewer elements (e.g. geometric primitives) than image pixels. In those cases, object order algorithms are usually most efficient (e.g. scan conversion or shear warp). But when the scene complexity exceeds that of the image, such as is the case often in volume rendering, then image order algorithms (e.g., ray casting Ray casting is the methodological basis for 3D CAD/CAM solid modeling and image rendering. It is essentially the same as ray tracing for computer graphics where virtual light rays are "cast" or "traced" on their path from the focal point of a came ...) may be more efficient. References {{Reflist 3D rendering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volume Rendering
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set, typically a 3D scalar field. A typical 3D data set is a group of 2D slice images acquired by a CT, MRI, or MicroCT scanner. Usually these are acquired in a regular pattern (e.g., one slice for each millimeter of depth) and usually have a regular number of image pixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel. To render a 2D projection of the 3D data set, one first needs to define a camera in space relative to the volume. Also, one needs to define the opacity and color of every voxel. This is usually defined using an RGBA (for red, green, blue, alpha) transfer function that defines the RGBA value for every possible voxel value. For example, a volu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLSL
OpenGL Shading Language (GLSL) is a high-level shading language with a syntax based on the C programming language. It was created by the OpenGL ARB (OpenGL Architecture Review Board) to give developers more direct control of the graphics pipeline without having to use ARB assembly language or hardware-specific languages. Background With advances in graphics cards, new features have been added to allow for increased flexibility in the rendering pipeline at the vertex and fragment level. Programmability at this level is achieved with the use of fragment and vertex shaders. Originally, this functionality was achieved by writing shaders in ARB assembly language – a complex and unintuitive task. The OpenGL ARB created the OpenGL Shading Language to provide a more intuitive method for programming the graphics processing unit while maintaining the open standards advantage that has driven OpenGL throughout its history. Originally introduced as an extension to OpenGL 1.4, GLSL was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shadertoy
Shadertoy.com is an online community and tool for creating and sharing shaders through WebGL, used for both learning and teaching 3D computer graphics in a web browser. Overview Shadertoy.com is an online community and platform for computer graphics professionals, academicshttp://graphics.cs.williams.edu/courses/cs371/f14/reading/shadertoy.pdf and enthusiasts who share, learn and experiment with rendering techniques and procedural art through GLSL code. There are more than 52 thousand public contributions as of mid-2021 coming from thousands of users. WebGL allows Shadertoy to access the compute power of the GPU to generate procedural art, animation, models, lighting, state based logic and sound. History Shadertoy.com was created by Pol Jeremias and Inigo Quilez in January 2013 and came online in February the same year. The roots of the effort are in Inigo's "Shadertoy" section in his computer graphics educational website. With the arrival of the initial WebGL implement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avizo (software)
Avizo (pronounce: ‘a-VEE-zo’) is a general-purpose commercial software application for scientific and industrial data visualization and analysis. Avizo is developed by Thermo Fisher Scientific and was originally designed and developed by the Visualization and Data Analysis Group at Zuse Institute Berlin (ZIB) under the name Amira. Avizo was commercially released in November 2007. For the history of its development, see the Wikipedia article about Amira. Overview Avizo is a software application which enables users to perform interactive visualization and computation on 3D data sets. The Avizo interface is modelled on the visual programming. Users manipulate data and module components, organized in an interactive graph representation (called Pool), or in a Tree view. Data and modules can be interactively connected together, and controlled with several parameters, creating a visual processing network whose output is displayed in a 3D viewer. With this interface, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Inventor
Open Inventor, originally IRIS Inventor, is a C++ object-oriented retained mode 3D graphics toolkit designed by SGI to provide a higher layer of programming for OpenGL. Its main goals are better programmer convenience and efficiency. Open Inventor exists as both proprietary software and free and open-source software, subject to the requirements of the GNU Lesser General Public License (LGPL), version 2.1. Early history Around 1988–1989, Wei Yen asked Rikk Carey to lead the IRIS Inventor project. Their goal was to create a toolkit that made developing 3D graphics applications easier to do. The strategy was based on the premise that people were not developing enough 3D applications with IRIS GL because it was too time-consuming to do so with the low-level interface provided by IRIS GL. If 3D programming were made easier, through the use of an object oriented API, then more people would create 3D applications and SGI would benefit. Therefore, the credo was always “ease of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amira (Software)
Amira (pronounce: Ah-meer-ah) is a software platform for 3D and 4D data visualization, processing, and analysis. It is being actively developed by Thermo Fisher Scientific in collaboration with the Zuse Institute Berlin (ZIB), and commercially distributed by Thermo Fisher Scientific. Overview Amira is an extendable software system for scientific visualization, data analysis, and presentation of 3D and 4D data. It is used by thousands of researchers and engineers in academia and industry around the world. Its flexible user interface and modular architecture make it a universal tool for processing and analysis of data from various modalities; e.g. micro-CT, PET, Ultrasound. Its ever-expanding functionality has made it a versatile data analysis and visualization solution, applicable to and being used in many fields, such as microscopy in biology and materials science, molecular biology, quantum physics, astrophysics, computational fluid dynamics (CFD), finite element modeling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Normal
In geometry, a normal is an object such as a line, ray, or vector that is perpendicular to a given object. For example, the normal line to a plane curve at a given point is the (infinite) line perpendicular to the tangent line to the curve at the point. A normal vector may have length one (a unit vector) or its length may represent the curvature of the object (a '' curvature vector''); its algebraic sign may indicate sides (interior or exterior). In three dimensions, a surface normal, or simply normal, to a surface at point P is a vector perpendicular to the tangent plane of the surface at P. The word "normal" is also used as an adjective: a line ''normal'' to a plane, the ''normal'' component of a force, the normal vector, etc. The concept of normality generalizes to orthogonality (right angles). The concept has been generalized to differentiable manifolds of arbitrary dimension embedded in a Euclidean space. The normal vector space or normal space of a manifold at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deferred Shading
In the field of 3D computer graphics, deferred shading is a screen-space shading technique that is performed on a second rendering pass, after the vertex and pixel shaders are rendered. It was first suggested by Michael Deering in 1988. On the first pass of a deferred shader, only data that is required for shading computation is gathered. Positions, normals, and materials for each surface are rendered into the geometry buffer (G-buffer) using " render to texture". After this, a pixel shader computes the direct and indirect lighting at each pixel using the information of the texture buffers in screen space. Screen space directional occlusion can be made part of the deferred shading pipeline to give directionality to shadows and interreflections. Advantages The primary advantage of deferred shading is the decoupling of scene geometry from lighting. Only one geometry pass is required, and each light is only computed for those pixels that it actually affects. This gives the abi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screen Space Reflection
Reflection in computer graphics is used to emulate reflective objects like mirrors and shiny surfaces. Accurate reflections can be accomplished e.g. by a ray trace renderer by following a ray from the eye to the mirror and then calculating where it bounces from, and continuing the process until no surface is found, or a non-reflective surface is found. Approximate reflections can usually be computed faster by using methods such as environment mapping. Reflection on a shiny surface like wood or tile can add to the photorealistic effects of a 3D rendering. Approaches to reflection rendering For rendering environment reflections there exist many techniques that differ in precision, computational and implementation complexity. Combination of these techniques are also possible. Image order rendering algorithms based on tracing rays of light, such as ray tracing or path tracing, typically compute accurate reflections on general surfaces, including multiple reflections and self ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signed Distance Function
In mathematics and its applications, the signed distance function (or oriented distance function) is the orthogonal distance of a given point ''x'' to the boundary of a set Ω in a metric space, with the sign determined by whether or not ''x'' is in the interior of Ω. The function has positive values at points ''x'' inside Ω, it decreases in value as ''x'' approaches the boundary of Ω where the signed distance function is zero, and it takes negative values outside of Ω. However, the alternative convention is also sometimes taken instead (i.e., negative inside Ω and positive outside). Definition If Ω is a subset of a metric space ''X'' with metric ''d'', then the ''signed distance function'' ''f'' is defined by :f(x) = \begin d(x, \partial \Omega) & \mbox\, x \in \Omega \\ -d(x, \partial \Omega) & \mbox\, x \in \Omega^c \end where \partial \Omega denotes the boundary of For any : d(x, \partial \Omega) := \inf_d(x, y) where denotes the infimum. Properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visualization Of SDF Ray Marching Algorithm
Visualization or visualisation may refer to: *Visualization (graphics), the physical or imagining creation of images, diagrams, or animations to communicate a message * Data visualization, the graphic representation of data * Information visualization, the study of visual representations of abstract data * Music visualization, animated imagery based on a piece of music *Mental image, the experience of images without the relevant external stimuli * "Visualization", a song by Blank Banshee on the 2012 album ''Blank Banshee 0'' See also * Creative visualization (other) * Visualizer (other) * * * * Graphics * List of graphical methods, various forms of visualization * Guided imagery, a mind-body intervention by a trained practitioner * Illustration, a decoration, interpretation or visual explanation of a text, concept or process * Image, an artifact that depicts visual perception, such as a photograph or other picture * Infographics Infographics (a clippe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
