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Heightmap
In computer graphics, a heightmap or heightfield is a raster image used mainly as Discrete Global Grid in secondary elevation modeling. Each pixel stores values, such as surface elevation data, for display in 3D computer graphics. A heightmap can be used in bump mapping to calculate where this 3D data would create shadow in a material, in displacement mapping to displace the actual geometric position of points over the textured surface, or for terrain where the heightmap is converted into a 3D mesh. A heightmap contains one channel interpreted as a distance of displacement or "height" from the "floor" of a surface and sometimes visualized as luma of a grayscale image, with black representing minimum height and white representing maximum height. When the map is rendered, the designer can specify the amount of displacement for each unit of the height channel, which corresponds to the “contrast” of the image. Heightmaps can be stored by themselves in existing graysc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heightmap Rendered
In computer graphics, a heightmap or heightfield is a raster image used mainly as Discrete Global Grid in secondary elevation modeling. Each pixel stores values, such as surface elevation data, for display in 3D computer graphics. A heightmap can be used in bump mapping to calculate where this 3D data would create shadow in a material, in displacement mapping to displace the actual geometric position of points over the textured surface, or for terrain where the heightmap is converted into a 3D mesh. A heightmap contains one channel interpreted as a distance of displacement or "height" from the "floor" of a surface and sometimes visualized as luma of a grayscale image, with black representing minimum height and white representing maximum height. When the map is rendered, the designer can specify the amount of displacement for each unit of the height channel, which corresponds to the “contrast” of the image. Heightmaps can be stored by themselves in existing grayscale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picogen
Picogen is a rendering system for the creation and rendering of artificial terrain, based on ray tracing. It is free software. Overview While the primary purpose of picogen is to display realistic 3D terrain, both in terms of terrain formation ''and'' image plausibility, it also is a heightmap-creation tool, in which heightmaps are programmed in a syntax reminiscent of Lisp. The shading system is partially programmable. Example features * Whitted-Style ray tracer for quick previews * Rudimentary path tracer for high quality results * Partial implementation of Preetham's Sun-/Skylight Model * Procedural heightmaps, though before rendering they are tesselated Frontends Currently there is a frontend to picogen, called picogen-wx (based on wxWidgets). It is encapsulated from picogen and thus communicates with it on command-line level. Picogen-wx provides several panels to design the different aspects of a landscape, e.g. the Sun/Sky- or the Terrain-Texture-Panel. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bump Mapping
Bump mapping is a texture mapping technique in computer graphics for simulating bumps and wrinkles on the surface of an object. This is achieved by perturbing the surface normals of the object and using the perturbed normal during lighting calculations. The result is an apparently bumpy surface rather than a smooth surface, although the surface of the underlying object is not changed. Bump mapping was introduced by James Blinn in 1978.Blinn, James F"Simulation of Wrinkled Surfaces" Computer Graphics, Vol. 12 (3), pp. 286-292 SIGGRAPH-ACM (August 1978) Normal mapping is the most common variation of bump mapping used. Principles Bump mapping is a technique in computer graphics to make a rendered surface look more realistic by simulating small displacements of the surface. However, unlike displacement mapping, the surface geometry is not modified. Instead only the surface normal is modified as if the surface had been displaced. The modified surface normal is then used for li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voxel
In computing, a voxel is a representation of a value on a three-dimensional regular grid, akin to the two-dimensional pixel. Voxels are frequently used in the Data visualization, visualization and analysis of medical imaging, medical and scientific data (e.g. geographic information systems (GIS)). Voxels also have technical and artistic applications in video games, largely originating with surface rendering in ''Outcast (video game), Outcast'' (1999). ''Minecraft'' (2011) makes use of an entirely voxelated world to allow for a fully destructable and constructable environment. Voxel art, of the sort used in ''Minecraft'' and elsewhere, is a style and format of 3D art analogous to pixel art. As with pixels in a 2D bitmap, voxels themselves do not typically have their position (i.e. coordinates) explicitly encoded with their values. Instead, Rendering (computer graphics), rendering systems infer the position of a voxel based upon its position relative to other voxels (i.e., its pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (graphics), ray tracing for computer graphics where virtual light rays are "cast" or "traced" on their path from the focal point of a camera through each pixel in the camera sensor to determine what is visible along the ray in the 3D scene. The term "Ray Casting" was introduced by Scott Roth while at the General Motors Research Labs from 1978–1980. His paper, "Ray Casting for Modeling Solids", describes modeled solid objects by combining primitive solids, such as blocks and cylinders, using the set operators union (+), intersection (&), and difference (−). The general idea of using these binary operators for solid modeling is largely due to Voelcker and Requicha's geometric modelling group at the University of Rochester. See ''solid modeling'' for a broad overview of solid modeling methods. Before ray casting (and ray tracing), computer graphics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terragen
Terragen is a scenery generator program for Microsoft Windows and Mac OS X developed and published by Planetside Software. It can be used to create renderings and animations of landscapes. History Released in stages (tech preview and beta) to a participating community, Terragen 2 was released to pre-purchasers on 2 April 2009. Terragen 2 is offered in feature limited freeware and full-featured commercial licenses. Planetside Software released the first public version of Terragen 2 after more than three years of development of both the core technologies and the program itself. Since then there have been several released updates to both licenses of the software along the development cycle with a series of technology previews and a beta release. The "final" build was released on April 23, 2009, and more updates, including feature modules, are expected to be released later. Planetside released Terragen 3 in August 2013. Version 3.1 was released in February 2014. Version 4 was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Elevation Model
A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, Natural satellite, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced Relief mapping (computer graphics), relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top Canopy (biology), canopy or building roofs. While a DSM may be useful for Landscape planning, landscape modeling, Urban planning, city modeling and visualization applications, a DTM is often required for flood or drainage modeling, Land-use planning, land-use studies, geological applications, and other applications, and in planetary science. Terminology There is no universal usage of the terms ''digital elevation model'' (DEM), ''di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement Mapping
Displacement mapping is an alternative computer graphics technique in contrast to bump, normal, and parallax mapping, using a texture or height map to cause an effect where the actual geometric position of points over the textured surface are ''displaced'', often along the local surface normal, according to the value the texture function evaluates to at each point on the surface. It gives surfaces a sense of depth and detail, permitting in particular self-occlusion, self-shadowing and silhouettes; on the other hand, it is the most costly of this class of techniques owing to the large amount of additional geometry. For years, displacement mapping was a peculiarity of high-end rendering systems like PhotoRealistic RenderMan, while realtime APIs, like OpenGL and DirectX, were only starting to use this feature. One of the reasons for this is that the original implementation of displacement mapping required an adaptive tessellation of the surface in order to obtain enough microp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discrete Global Grid
A discrete global grid (DGG) is a mosaic that covers the entire Earth's surface. Mathematically it is a space partitioning: it consists of a set of non-empty regions that form a partition of the Earth's surface. In a usual grid-modeling strategy, to simplify position calculations, each region is represented by a point, abstracting the grid as a set of region-points. Each region or region-point in the grid is called a cell. When each cell of a grid is subject to a recursive partition, resulting in a "series of discrete global grids with progressively finer resolution", forming a hierarchical grid, it is called a hierarchical DGG (sometimes "global hierarchical tessellation" or "DGG system"). Discrete global grids are used as the geometric basis for the building of geospatial data structures. Each cell is related with data objects or values, or (in the hierarchical case) may be associated with other cells. DGGs have been proposed for use in a wide range of geospatial applicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raster Graphics
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for red, green and blue. In computer graphics and digital photography, a raster graphic, raster image, or simply raster is a two-dimensional image or picture represented as a rectangular Matrix (mathematics), matrix or grid of pixels, viewable via a computer display, paper, or other display medium. A raster image is technically characterized by the width and height of the image in pixels and by the number of bits per pixel. Raster images are stored in image files with varying dissemination, production, generation, and acquisition formats. The printing and prepress industries know raster graphics as contones (from "continuous tones"). In contrast, '' line art'' is usually implemented as vector graphics in digital systems. Many raster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simplex Noise
Simplex noise is the result of an ''n''-dimensional noise function comparable to Perlin noise ("classic" noise) but with fewer directional artifacts, in higher dimensions, and a lower computational overhead. Ken Perlin designed the algorithm in 2001 to address the limitations of his classic noise function, especially in higher dimensions. The advantages of simplex noise over Perlin noise: * Simplex noise has lower computational complexity and requires fewer multiplications. * Simplex noise scales to higher dimensions (4D, 5D) with much less computational cost: the complexity is O(n^2) for n dimensions instead of the O(n\,2^n) of classic noise. * Simplex noise has no noticeable directional artifacts (is visually isotropic), though noise generated for different dimensions is visually distinct (e.g. 2D noise has a different look than 2D slices of 3D noise, and it looks increasingly worse for higher dimensions). * Simplex noise has a well-defined and continuous gradient (almost) eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
