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Cel Shading
Cel shading or toon shading is a type of non-photorealistic rendering designed to make 3D computer graphics appear to be flat by using less shading color instead of a shade gradient or tints and shades. A cel shader is often used to mimic the style of a comic book or cartoon and/or give the render a characteristic paper-like texture. There are similar techniques that can make an image look like a sketch, an oil painting or an ink painting. The name comes from ''cels'' (short for celluloid), clear sheets of acetate which are painted on for use in traditional 2D animation. Basic process The cel-shading process starts with a typical 3D model. Where cel-shading differs from conventional rendering is in its non-photorealistic shading algorithm. Conventional smooth lighting values are calculated for each pixel and then quantized to a small number of discrete shades to create the characteristic "flat look", where the shadows and highlights appear as blocks of color rathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Color Quantization
In computer graphics, color quantization or color image quantization is quantization applied to color spaces; it is a process that reduces the number of distinct colors used in an image, usually with the intention that the new image should be as visually similar as possible to the original image. Computer algorithms to perform color quantization on bitmaps have been studied since the 1970s. Color quantization is critical for displaying images with many colors on devices that can only display a limited number of colors, usually due to memory limitations, and enables efficient compression of certain types of images. The name "color quantization" is primarily used in computer graphics research literature; in applications, terms such as ''optimized palette generation'', ''optimal palette generation'', or ''decreasing color depth'' are used. Some of these are misleading, as the palettes generated by standard algorithms are not necessarily the best possible. Algorithms Most standar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Image Processing
An image or picture is a visual representation. An image can be two-dimensional, such as a drawing, painting, or photograph, or three-dimensional, such as a carving or sculpture. Images may be displayed through other media, including a projection on a surface, activation of electronic signals, or digital displays; they can also be reproduced through mechanical means, such as photography, printmaking, or photocopying. Images can also be animated through digital or physical processes. In the context of signal processing, an image is a distributed amplitude of color(s). In optics, the term ''image'' (or ''optical image'') refers specifically to the reproduction of an object formed by light waves coming from the object. A ''volatile image'' exists or is perceived only for a short period. This may be a reflection of an object by a mirror, a projection of a camera obscura, or a scene displayed on a cathode-ray tube. A ''fixed image'', also called a hard copy, is one that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Multitexturing
Texture mapping is a term used in computer graphics to describe how 2D images are projected onto 3D models. The most common variant is the UV unwrap, which can be described as an inverse paper cutout, where the surfaces of a 3D model are cut apart so that it can be unfolded into a 2D coordinate space (UV Space). Semantic Texture mapping can both refer to the task of unwrapping a 3D model, the abstract that a 3D model has textures applied to it and the related algorithm of the 3D software. Texture map refers to a Raster graphics also called image, texture. If the texture stores a specific property it's also referred to as color map, roughness map, etc. The coordinate space which converts from the 3D space of a 3D model into a 2D space so that it can sample from the Texture map is called: UV Space, UV Coordinates, Texture Space. Algorithm A simplified explanation of how an algorithm could work to render an image: # For each pixel we trace the coordinates of the screen i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Celshading Teapot Large
Cel shading or toon shading is a type of non-photorealistic rendering designed to make 3D computer graphics appear to be flat by using less shading color instead of a Color gradient, shade gradient or tints and shades. A cel shader is often used to mimic the style of a comic book or cartoon and/or give the render a characteristic paper-like texture. There are similar techniques that can make an image look like a Sketch (drawing), sketch, an oil painting or an ink painting. The name comes from cel, ''cels'' (short for celluloid), clear sheets of acetate which are painted on for use in Traditional animation, traditional 2D animation. Basic process The cel-shading process starts with a typical 3D computer graphics#Modeling, 3D model. Where cel-shading differs from conventional rendering is in its non-photorealistic shader, shading algorithm. Conventional smooth lighting values are calculated for each pixel and then Color quantization, quantized to a small number of discrete s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Z-buffering
A z-buffer, also known as a depth buffer, is a type of data buffer used in computer graphics to store the depth information of fragments. The values stored represent the distance to the camera, with 0 being the closest. The encoding scheme may be flipped with the highest number being the value closest to camera. In a 3D-rendering pipeline, when an object is projected on the screen, the depth (z-value) of a generated fragment in the projected screen image is compared to the value already stored in the buffer (depth test), and replaces it if the new value is closer. It works in tandem with the rasterizer, which computes the colored values. The fragment output by the rasterizer is saved if it is not overlapped by another fragment. Z-buffering is a technique used in almost all contemporary computers, laptops, and mobile phones for generating 3D computer graphics. The primary use now is for video games, which require fast and accurate processing of 3D scenes. Usage Occlusion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Compositing
Compositing is the process or technique of combining visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live action, Live-action shooting for compositing is variously called "chroma key", "blue screen", "green screen" and other names. Today, most compositing is achieved through digital image manipulation. Pre-digital compositing techniques, however, go back as far as the trick films of Georges Méliès in the late 19th century, and some are still in use. Basic procedure All compositing involves the replacement of selected parts of an image with other material, usually, but not always, from another image. In the digital method of compositing, software commands designate a narrowly defined color as the part of an image to be replaced. Then the software (e.g. Natron (software), Natron) replaces every pixel within the designated color range with a pixel from another image, aligned to appear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Vertex Shader
In computer graphics, a shader is a computer program that calculates the appropriate levels of light, darkness, and color during the rendering of a 3D scene—a process known as '' shading''. Shaders have evolved to perform a variety of specialized functions in computer graphics special effects and video post-processing, as well as general-purpose computing on graphics processing units. Traditional shaders calculate rendering effects on graphics hardware with a high degree of flexibility. Most shaders are coded for (and run on) a graphics processing unit (GPU), though this is not a strict requirement. ''Shading languages'' are used to program the GPU's rendering pipeline, which has mostly superseded the fixed-function pipeline of the past that only allowed for common geometry transforming and pixel-shading functions; with shaders, customized effects can be used. The position and color ( hue, saturation, brightness, and contrast) of all pixels, vertices, and/or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Vertex Normal
In the geometry of computer graphics, a vertex normal at a vertex of a polyhedron is a directional vector associated with a vertex, intended as a replacement to the true geometric normal of the surface. Commonly, it is computed as the normalized average of the surface normals of the faces that contain that vertex. The average can be weighted for example by the area of the face or it can be unweighted. Vertex normals can also be computed for polygonal approximations to surfaces such as NURBS, or specified explicitly for artistic purposes. Vertex normals are used in Gouraud shading, Phong shading and other lighting models. Using vertex normals, much smoother shading than flat shading Shading refers to the depiction of depth perception in 3D models (within the field of 3D computer graphics) or illustrations (in visual art) by varying the level of darkness. Shading tries to approximate local behavior of light on the object's ... can be achieved; however, without some modif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Wire Frame Model
In 3D computer graphics, a wire-frame model (also spelled wireframe model) is a visual representation of a three-dimensional (3D) physical object. It is based on a polygon mesh or a volumetric mesh, created by specifying each edge of the physical object where two mathematically continuous smooth surfaces meet, or by connecting an object's constituent vertices using (straight) lines or curves. The object is projected into screen space and rendered by drawing lines at the location of each edge. The term "wire frame" comes from designers using metal wire to represent the three-dimensional shape of solid objects. 3D wireframe computer models allow for the construction and manipulation of solids and solid surfaces. 3D solid modeling efficiently draws higher quality representations of solids than conventional line drawing. Using a wire-frame model allows for the visualization of the underlying design structure of a 3D model. Traditional two-dimensional views and drawings/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Silhouette
A silhouette (, ) is the image of a person, animal, object or scene represented as a solid shape of a single colour, usually black, with its edges matching the outline of the subject. The interior of a silhouette is featureless, and the silhouette is usually presented on a light background, usually white, or none at all. The silhouette differs from an line art, outline, which depicts the edge of an object in a linear form, while a silhouette appears as a solid shape. Silhouette images may be created in any visual artistic medium, but were first used to describe pieces of cut paper, which were then stuck to a backing in a contrasting colour, and often framed. Cutting portraits, generally in profile, from black card became popular in the mid-18th century, though the term ''silhouette'' was seldom used until the early decades of the 19th century, and the tradition has continued under this name into the 21st century. They represented a cheap but effective alternative to the portrait m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |