HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 286

M glMaterials 286 glMaterial takes three arguments. The first, face, specifies whether the GL_FRONT materials, the GL_BACK materials, or both GL_FRONT_AND_BACK materials will be modified. The second, pname, specifies which of several parameters in one or both sets will be modified. The third, params, specifies what value or values will be assigned to the specified parameter. Material parameters are used in the lighting equation that is optionally applied to each vertex. The equation is discussed in the glLightModel reference page. The parameters that can be specified using glMaterial, and their interpretations by the lighting equation, are as follows: GL_AMBIENT params contains four integer or floating-point values that specify the ambient RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to - 1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial ambient reflectance for both front- and back-facing materials is (0.2, 0.2, 0.2, 1.0). GL_DIFFUSE params contains four integer or floating-point values that specify the diffuse RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to - 1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial diffuse reflectance for both front- and back-facing materials is (0.8, 0.8, 0.8, 1.0). GL_SPECULAR params contains four integer or floating-point values that specify the specular RGBA reflectance of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to - 1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial specular reflectance for both front- and back-facing materials is (0, 0, 0, 1). GL_EMISSION params contains four integer or floating-point values that specify the RGBA emitted light intensity of the material. Integer values are mapped linearly such that the most positive representable value maps to 1.0, and the most negative representable value maps to - 1.0. Floating-point values are mapped directly. Neither integer nor floating-point values are clamped. The initial emission intensity for both front- and back-facing materials is (0, 0, 0, 1). GL_SHININESS params is a single integer or floating-point value that specifies the RGBA specular exponent of the material. Integer and floating-point values are mapped directly. Only values in the range [0, 128] are accepted. The initial specular exponent for both frontand back-facing materials is 0. GL_AMBIENT_AND_DIFFUSE Equivalent to calling glMaterial twice with the same parameter values, once with GL_AMBIENT and once with GL_DIFFUSE. GL_COLOR_INDEXES Chapter 11