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Reflection Mapping
In computer graphics, environment mapping, or reflection mapping, is an efficient image-based lighting technique for approximating the appearance of a reflective surface by means of a precomputed texture. The texture is used to store the image of the distant environment surrounding the rendered object. Several ways of storing the surrounding environment have been employed. The first technique was sphere mapping, in which a single texture contains the image of the surroundings as reflected on a spherical mirror. It has been almost entirely surpassed by cube mapping, in which the environment is projected onto the six faces of a cube and stored as six square textures or unfolded into six square regions of a single texture. Other projections that have some superior mathematical or computational properties include the paraboloid mapping, the pyramid mapping, the octahedron mapping, and the HEALPix mapping. Reflection mapping is one of several approaches to reflection rendering, along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spoon Fi
A spoon is a utensil consisting of a shallow bowl (also known as a head), oval or round, at the end of a handle. A type of cutlery (sometimes called flatware in the United States), especially as part of a place setting, it is used primarily for transferring food to the mouth. Spoons are also used in food preparation to measure, mix, stir and toss ingredients and for serving food. Present day spoons are made from metal (notably flat silver or silverware, plated or solid), wood, porcelain or plastic. There are a wide variety of spoons that are made of a variety of materials and by different cultures for many different uses and foods. Terminology The spoon consists of a ''bowl'' and a handle. A handle in a shape of a slender stick is frequently called a ''stem''. The stem can end in a sharp point or be crowned with a ''knop'', a decorative knob. The ''knop-top'' spoons with a variety of knop shapes described by colorful terms like "acorn", "writhen-end" (spiral ornament on a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Path
Optical path (OP) is the trajectory that a light ray follows as it propagates through an optical medium. The geometrical optical-path length or simply geometrical path length (GPD) is the length of a segment in a given OP, i.e., the Euclidean distance integrated along a ray between any two points. The mechanical length of an optical device can be reduced to less than the GPD by using folded optics. The ''optical path length'' in a homogeneous medium is the GPD multiplied by the refractive index of the medium. Factors affecting optical path Path of light in medium, or between two media is affected by the following: * Reflection ** Total internal reflection * Refraction * Dispersion of light * Absorption Simple materials used * Lenses * Prisms * Mirrors * Transparent materials (e.g. optical filters) * Translucent materials (e.g. frosted glass) * Opaque Opacity or opaque may refer to: * Impediments to (especially, visible) light: ** Opacities, absorption coefficients ** Opacity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthographic Projection (geometry)
Orthographic projection (also orthogonal projection and analemma) is a means of representing three-dimensional objects in two dimensions. Orthographic projection is a form of parallel projection in which all the projection lines are orthogonal to the projection plane, resulting in every plane of the scene appearing in affine transformation on the viewing surface. The obverse of an orthographic projection is an oblique projection, which is a parallel projection in which the projection lines are ''not'' orthogonal to the projection plane. The term ''orthographic'' sometimes means a technique in multiview projection in which principal axes or the planes of the subject are also parallel with the projection plane to create the ''primary views''. If the principal planes or axes of an object in an orthographic projection are ''not'' parallel with the projection plane, the depiction is called ''axonometric'' or an ''auxiliary views''. (''Axonometric projection'' is synonymous with ''par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphere
A sphere () is a Geometry, geometrical object that is a solid geometry, three-dimensional analogue to a two-dimensional circle. A sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the centre (geometry), centre of the sphere, and is the sphere's radius. The earliest known mentions of spheres appear in the work of the Greek mathematics, ancient Greek mathematicians. The sphere is a fundamental object in many fields of mathematics. Spheres and nearly-spherical shapes also appear in nature and industry. Bubble (physics), Bubbles such as soap bubbles take a spherical shape in equilibrium. spherical Earth, The Earth is often approximated as a sphere in geography, and the celestial sphere is an important concept in astronomy. Manufactured items including pressure vessels and most curved mirrors and lenses are based on spheres. Spheres rolling, roll smoothly in any direction, so mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphere Mapping
In computer graphics, sphere mapping (or spherical environment mapping) is a type of reflection mapping that approximates reflective surfaces by considering the environment to be an infinitely far-away spherical wall. This environment is stored as a texture depicting what a mirrored sphere would look like if it were placed into the environment, using an orthographic projection (as opposed to one with perspective). This texture contains reflective data for the entire environment, except for the spot directly behind the sphere. (For one example of such an object, see Escher's drawing Hand with Reflecting Sphere.) To use this data, the surface normal of the object, view direction from the object to the camera, and/or reflected direction from the object to the environment is used to calculate a texture coordinate to look up in the aforementioned texture map. The result appears like the environment is reflected in the surface of the object that is being rendered. Usage example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubble Spheremapmap
Bubble, Bubbles or The Bubble may refer to: Common uses * Bubble (physics), a globule of one substance in another, usually gas in a liquid ** Soap bubble * Economic bubble, a situation where asset prices are much higher than underlying fundamentals Arts, entertainment and media Fictional characters * Bubble, a character in ''Absolutely Fabulous'' * Bubbles, an oriole from the ''Angry Birds'' franchise * Bubble, in the video game '' Clu Clu Land'' * Bubbles (''The Wire'') * Bubbles (''Trailer Park Boys'') * Bubbles, a yellow tang fish in the ''Finding Nemo'' franchise * Bubbles, in ''Jabberjaw'' * Bubbles Utonium, in ''The Powerpuff Girls'' ** Bubbles (Miyako Gotokuji), in ''Powerpuff Girls Z'' * Bubbles (''The Adventures of Little Carp'') * Bubbles, in ''The Adventures of Timmy the Tooth'' * Bubbles the Clown, a doll used in the BBC's Test Card F * Cobra Bubbles, in ''Lilo & Stitch'' * Bubbles DeVere, in ''Little Britain'' * Bubbles Yablonsky, the protagonist in a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubble Spheremap
Bubble, Bubbles or The Bubble may refer to: Common uses * Bubble (physics), a globule of one substance in another, usually gas in a liquid ** Soap bubble * Economic bubble, a situation where asset prices are much higher than underlying fundamentals Arts, entertainment and media Fictional characters * Bubble, a character in ''Absolutely Fabulous'' * Bubbles, an oriole from the ''Angry Birds'' franchise * Bubble, in the video game '' Clu Clu Land'' * Bubbles (''The Wire'') * Bubbles (''Trailer Park Boys'') * Bubbles, a yellow tang fish in the ''Finding Nemo'' franchise * Bubbles, in ''Jabberjaw'' * Bubbles Utonium, in ''The Powerpuff Girls'' ** Bubbles (Miyako Gotokuji), in ''Powerpuff Girls Z'' * Bubbles (''The Adventures of Little Carp'') * Bubbles, in ''The Adventures of Timmy the Tooth'' * Bubbles the Clown, a doll used in the BBC's Test Card F * Cobra Bubbles, in ''Lilo & Stitch'' * Bubbles DeVere, in ''Little Britain'' * Bubbles Yablonsky, the protagonist in a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brushed Metal
A piece of brushed aluminium A collection of brushed stainless steel Breville small appliances A DeLorean featuring non-structural brushed stainless steel panels The Gateway Arch in St. Louis, Missouri ">St._Louis,_Missouri.html" ;"title="Gateway Arch in St. Louis, Missouri">Gateway Arch in St. Louis, Missouri Brushed or dull polished metal is metal with a unidirectional satin Surface finishing, finish. It is produced by Polishing (metalworking), polishing the metal with a 120–180 Grit size, grit belt or wheel then softening with an 80–120 grit greaseless compound or a medium non-woven abrasive belt or pad. Commonly brushed metals include stainless steel, aluminium and nickel. Brushed finishes are popular in both small appliances and whiteware, and feature in architecture and automotive design. The Gateway Arch and DMC DeLorean are both clad in brushed stainless steel. The intensity of the brushed finish is specified as a surface roughness and is typically 0.5–1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Mapping
In 3D computer graphics, normal mapping, or Dot3 bump mapping, is a texture mapping technique used for faking the lighting of bumps and dents – an implementation of bump mapping. It is used to add details without using more polygons. A common use of this technique is to greatly enhance the appearance and details of a low polygon model by generating a normal map from a high polygon model or height map. Normal maps are commonly stored as regular RGB images where the RGB components correspond to the X, Y, and Z coordinates, respectively, of the surface normal. History In 1978 Jim Blinn described how the normals of a surface could be perturbed to make geometrically flat faces have a detailed appearance. The idea of taking geometric details from a high polygon model was introduced in "Fitting Smooth Surfaces to Dense Polygon Meshes" by Krishnamurthy and Levoy, Proc. SIGGRAPH 1996, where this approach was used for creating displacement maps over nurbs. In 1998, two papers were pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convex Set
In geometry, a subset of a Euclidean space, or more generally an affine space over the reals, is convex if, given any two points in the subset, the subset contains the whole line segment that joins them. Equivalently, a convex set or a convex region is a subset that intersects every line into a single line segment (possibly empty). For example, a solid cube is a convex set, but anything that is hollow or has an indent, for example, a crescent shape, is not convex. The boundary of a convex set is always a convex curve. The intersection of all the convex sets that contain a given subset of Euclidean space is called the convex hull of . It is the smallest convex set containing . A convex function is a real-valued function defined on an interval with the property that its epigraph (the set of points on or above the graph of the function) is a convex set. Convex minimization is a subfield of optimization that studies the problem of minimizing convex functions over convex se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances. To measure large distances, such as the distance of a planet or a star from Earth, astronomers use the principle of parallax. Here, the term ''parallax'' is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder. Parallax also affects optical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 surface and is not to be confused with techniques of adding shadows, such as shadow mapping or shadow volumes, which fall under global behavior of light. In drawing Shading is used traditionally in drawing for depicting a range of darkness by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas. Light patterns, such as objects having light and shaded areas, help when creating the illusion of depth on paper. There are various techniques of shading, including cross hatching, where perpendicular lines of varying closeness are drawn in a grid pattern to shade an area. The closer the lines are together, the darker the area appears. Likewise, the farther apart the lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
