Solid angle to the unit sphere with center P, which can be calculated as the surface integral: where formula_5 is the unit vector corresponding to formula_6, the position vector of an infinitesimal area of surface with respect to point P, and where formula_7 represents the unit normal vector to . Even if the projection on the unit sphere to the surface S is not isomorphic, the multiple folds are correctly considered according to the surface orientation described by the sign of the scalar product formula_8. Thus one can approximate the solid angle subtended by a small facet having flat surface area ,
Solid surface injected into molds to produce various solid decorative design figures. Solid-surface manufacturing companies may be members of the trade organizations American Composites Manufacturers Association, ISFA (International Surface Fabricators Association, and ICPA (International Cast Polymer Association). These organizations identify the product under the "brand" of MasterCast Engineered Composites. Solid surface can also be moulded using dedicated moulds. For example free standing baths are manufactured using a 2-part mould tool which creates a cavity for the material to be poured into. Once the mould has been prepared for casting, the material is mixed and degassed in an automated casting machine. It is