glMaterialf, glMateriali, glMaterialfv, glMaterialiv

[New - Windows 95, OEM Service Release 2]

These functions specify material parameters for the lighting model.

void glMaterialf(

void glMateriali(

Parameters

face

The face or faces that are being updated. Must be one of GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.

pname

The single-valued material parameter of the face or faces being updated. Must be GL_SHININESS.

param

The value that parameter GL_SHININESS will be set to.

void glMaterialfv(

void glMaterialiv(

Parameters

face

The face or faces that are being updated. Must be one of GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.

pname

The material parameter of the face or faces being updated. The parameters that can be specified using glMaterial, and their interpretations by the lighting equation, are as follows:

GL_AMBIENT

The params parameter 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 default ambient reflectance for both front- and back-facing materials is (0.2, 0.2, 0.2, 1.0).

GL_DIFFUSE

The params parameter 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 default diffuse reflectance for both front- and back-facing materials is (0.8, 0.8, 0.8, 1.0).

GL_SPECULAR

The params parameter 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 default specular reflectance for both front- and back-facing materials is (0.0, 0.0, 0.0, 1.0).

GL_EMISSION

The params parameter 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 default emission intensity for both front- and back-facing materials is (0.0, 0.0, 0.0, 1.0).

GL_SHININESS

The params parameter 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 default specular exponent for both front- and 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

The params parameter contains three integer or floating-point values specifying the color indexes for ambient, diffuse, and specular lighting. These three values, and GL_SHININESS, are the only material values used by the color-index mode lighting equation. Refer to glLightModel21E1NBY for a discussion of color-index lighting.

params

A pointer to the value or values to which pname will be set.

Remarks

The glMaterial function assigns values to material parameters. There are two matched sets of material parameters. One, the front-facing set, is used to shade points, lines, bitmaps, and all polygons (when two-sided lighting is disabled), or just front-facing polygons (when two-sided lighting is enabled). The other set, back-facing, is used to shade back-facing polygons only when two-sided lighting is enabled. Refer to glLightModel21E1NBY for details concerning one- and two-sided lighting calculations.

The glMaterial function 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 glLightModel21E1NBY.

The material parameters can be updated at any time. In particular, glMaterial can be called between a call to glBeginONJASG and the corresponding call to glEnd. If only a single material parameter is to be changed per vertex, however, glColorMaterial2U57YMP is preferred over glMaterial.

The following function retrieves information related to glMaterial:

glGetMaterialFAJHUB

Error Codes

The following are the error codes generated and their conditions.

See Also