<Dl> <Dd> Shading refers to depicting depth in 3D models or illustrations by varying levels of darkness . It is a process used in drawing for depicting levels of darkness on paper by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas . 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 lines are, the lighter the area appears . The term has been recently generalized to mean that shaders are applied . </Dd> </Dl> <Dd> Shading refers to depicting depth in 3D models or illustrations by varying levels of darkness . It is a process used in drawing for depicting levels of darkness on paper by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas . 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 lines are, the lighter the area appears . The term has been recently generalized to mean that shaders are applied . </Dd> <Dl> <Dt> Texture mapping </Dt> <Dd> Texture mapping is a method for adding detail, surface texture, or colour to a computer - generated graphic or 3D model . Its application to 3D graphics was pioneered by Dr Edwin Catmull in 1974 . A texture map is applied (mapped) to the surface of a shape, or polygon . This process is akin to applying patterned paper to a plain white box . Multitexturing is the use of more than one texture at a time on a polygon . Procedural textures (created from adjusting parameters of an underlying algorithm that produces an output texture), and bitmap textures (created in an image editing application or imported from a digital camera) are, generally speaking, common methods of implementing texture definition on 3D models in computer graphics software, while intended placement of textures onto a model's surface often requires a technique known as UV mapping (arbitrary, manual layout of texture coordinates) for polygon surfaces, while non-uniform rational B - spline (NURB) surfaces have their own intrinsic parameterization used as texture coordinates . Texture mapping as a discipline also encompasses techniques for creating normal maps and bump maps that correspond to a texture to simulate height and specular maps to help simulate shine and light reflections, as well as environment mapping to simulate mirror - like reflectivity, also called gloss . </Dd> </Dl> <Dd> Texture mapping is a method for adding detail, surface texture, or colour to a computer - generated graphic or 3D model . Its application to 3D graphics was pioneered by Dr Edwin Catmull in 1974 . A texture map is applied (mapped) to the surface of a shape, or polygon . This process is akin to applying patterned paper to a plain white box . Multitexturing is the use of more than one texture at a time on a polygon . Procedural textures (created from adjusting parameters of an underlying algorithm that produces an output texture), and bitmap textures (created in an image editing application or imported from a digital camera) are, generally speaking, common methods of implementing texture definition on 3D models in computer graphics software, while intended placement of textures onto a model's surface often requires a technique known as UV mapping (arbitrary, manual layout of texture coordinates) for polygon surfaces, while non-uniform rational B - spline (NURB) surfaces have their own intrinsic parameterization used as texture coordinates . Texture mapping as a discipline also encompasses techniques for creating normal maps and bump maps that correspond to a texture to simulate height and specular maps to help simulate shine and light reflections, as well as environment mapping to simulate mirror - like reflectivity, also called gloss . </Dd>

What is graph and its types in computer graphics