 An example of reflection mapping.
 Environment mapping is the foundation for image-based lighting, seen here in this screenshot of rthdribl. In computer graphics, reflection mapping is an efficient method of simulating a complex mirroring surface by means of a precomputed texture image. The texture is used to store the image of the environment surrounding the rendered object. There are several ways of storing the surrounding environment; the most common ones are the Standard Environment Mapping in which a single texture contains the image of the surrounding as reflected on a mirror ball, or the Cubic Environment Mapping in which the envirornment is unfolded onto the six faces of a cube and stored therefore as six square textures. Image File history File links No higher resolution available. ...
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This teapot was illuminated using an HDR environment map of St. ...
Computer graphics is a sub-field of computer science and is concerned with digitally synthesizing and manipulating visual content. ...
This kind of approach is more efficient than the classical ray tracing approach of computing the exact reflection by shooting a ray and following its optically exact path, but it should be noted that these are (sometimes crude) approximations of the real reflection. A typical drawback of this technique is the absence of self reflections: you cannot see any part of the reflected object inside the reflection itself. A ray traced scene. ...
Types of Reflection Mapping
Standard Environment Mapping Standard environment mapping, more commonly known as spherical environment mapping, involves the use of a textured sphere infinitely far away from the object that reflects it. By creating a spherical texture using a fisheye lens or via prerendering or with a light probe, this texture is mapped to a hollow sphere, and the texel colors are determined by calculating the light vectors from the points on the object to the texels in the environment map. This technique may produce results which are superficially similar to those produced by raytracing, but incurs less of a performance hit because all of the colors of the points to be referenced are known beforehand, so all it has to do is to calculate the angles of incidence and reflection. Fisheye 15 mm (type: equisolid angle), 35 mm-film, cropped by slide-frame. ...
A ray traced scene. ...
A ray traced scene. ...
Look up reflection in Wiktionary, the free dictionary. ...
There are a few glaring limitations to spherical mapping. For one thing, due to the nature of the texture used for the map, there is an abrupt point of singularity on the backside of objects using spherical mapping. Cube mapping (see below) was developed to address this issue. Since cube maps (if made and filtered correctly) have no visible seams, they are an obvious successor to the archaic sphere maps, and nowadays spherical environment maps are almost nonexistent in certain contemporary graphical applications, such as video game graphics. Namcos Pac-Man was a hit, and became a cultural phenomenon. ...
Cube Environment Mapping
 A diagram depicting an apparent reflection being provided by cube mapped reflection. The map is actually projected onto the surface from the point of view of the observer. Highlights which in raytracing would be provided by tracing the ray and determining the angle made with the normal, can be 'fudged', if they are manually painted into the texture field (or if they already appear there depending on how the texture map was obtained), from where they will be projected onto the mapped object along with the rest of the texture detail. Cube mapped reflection is a technique that uses cube mapping to make objects look like they reflect the environment around them. Generally, this is done with the same skybox that is used in outdoor renderings. Though this is not a true reflection since objects around the reflective one will not be seen in the reflection, the desired effect is usually achieved. Image File history File links No higher resolution available. ...
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In computer graphics, cube mapping is a technique that takes a three dimensional texture coordinate and returns a texel from a given cube map (very similar to a skyboxs textures format). ...
The clouds and sky in this Half-Life: Opposing Force screenshot are part of the skybox. ...
Cube mapped reflection is done by determining the vector that the object is being viewed at. This camera ray is reflected about the surface normal of where the camera vector intersects the object. This results in the reflected ray which is then passed to the cube map to get the texel which the camera then sees as if it is on the surface of the object. This creates the effect that the object is reflective. In physics and in vector calculus, a spatial vector, or simply vector, is a concept characterized by a magnitude and a direction. ...
A surface normal, or just normal to a flat surface is a three-dimensional vector which is perpendicular to that surface. ...
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History Precursor work in texture mapping had been established by Edwin Catmull, with refinements for curved surfaces by James Blinn, in 1974. [1] Blinn went on to further refine his work, developing environment mapping by 1976. [2] Edwin Catmull after receiving a medal at SIGGRAPH 2001. ...
Jim Blinn James Blinn is a computer graphics researcher and pioneer. ...
Gene Miller experimented with spherical environment mapping in 1982 at MAGI Synthavision. [3] With the assistance of Christine Chang, he photographed a Christmas ornament in the parking lot at MAGI. By cropping the photo of the ball down to its diameter, he was able to map it to a hollow sphere (see the process above) (Fig. 1). Next, he applied it to a blobby dog model created by Ken Perlin (Fig. 2), and superimposed the environment-mapped model into a photograph of the parking lot. The result can be seen in Fig. 3. This technique of environment mapping real-world environments enventually came to use in HDRI image-based lighting (see here). Gene Miller (1928-2005) was a longtime investigative reporter at The Miami Herald who won two Pulitzer Prizes for reporting that helped save innocent men on Floridas Death Row from execution. ...
1982 (MCMLXXXII) was a common year starting on Friday of the Gregorian calendar. ...
Dr. Ken Perlin is a Professor in the Department of Computer Science and the Director of the Media Research Laboratory, both at New York University. ...
In computer graphics and cinematography, high dynamic range imaging (HDRI for short) is a set of techniques that allow a far greater dynamic range of exposures than normal digital imaging techniques. ...
This teapot was illuminated using an HDR environment map of St. ...
Application in Real-Time 3D Graphics
Standard Environment Mapping
Cubic Environment Mapping
 Example of a three-dimensional model using cube mapped reflection Cube mapped reflection, when used correctly, may be the fastest method of rendering a reflective surface. To increase the speed of rendering, each vertex calculates the position of the reflected ray. Then, the position is interpolated across polygons to which the vertex is attached. This eliminates the need for recalculating every pixel's reflection. Image File history File links No higher resolution available. ...
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See also The clouds and sky in this Half-Life: Opposing Force screenshot are part of the skybox. ...
In computer graphics, cube mapping is a technique that takes a three dimensional texture coordinate and returns a texel from a given cube map (very similar to a skyboxs textures format). ...
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