void GLAPIENTRY glMaterialf( GLenum face,
GLenum pname,
GLfloat param )
void GLAPIENTRY glMateriali( GLenum face,
GLenum pname,
GLint param )
PARAMETERS
face Specifies which face or faces are being updated. Must be one of
GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.
pname Specifies the single-valued material parameter of the face or
faces that is being updated. Must be GL_SHININESS.
param Specifies the value that parameter GL_SHININESS will be set to.
C SPECIFICATION
void GLAPIENTRY glMaterialfv( GLenum face,
GLenum pname,
const GLfloat *params )
void GLAPIENTRY glMaterialiv( GLenum face,
GLenum pname,
const GLint *params )
PARAMETERS
face Specifies which face or faces are being updated. Must be one of
GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK.
pname Specifies the material parameter of the face or faces that is be‐
ing updated. Must be one of GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR,
GL_EMISSION, GL_SHININESS, GL_AMBIENT_AND_DIFFUSE, or
GL_COLOR_INDEXES.
params Specifies a pointer to the value or values that pname will be set
to.
DESCRIPTION
glMaterial 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 the
glLightModel reference page for details concerning one- and two-sided
lighting calculations.
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 sev‐
eral parameters in one or both sets will be modified. The third,
params, specifies what value or values will be assigned to the specified
parameter.
front- and back-facing materials is (0.2, 0.2, 0.2,
1.0).
GL_DIFFUSE params contains four integer or floating-point val‐
ues 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 val‐
ues 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 di‐
rectly. 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 val‐
ues 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 di‐
rectly. 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 ma‐
terial. Integer and floating-point values are
mapped directly. Only values in the range [0,128]
are accepted. The initial 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 params contains three integer or floating-point val‐
ues specifying the color indices for ambient, dif‐
fuse, and specular lighting. These three values,
and GL_SHININESS, are the only material values used
ERRORS
GL_INVALID_ENUM is generated if either face or pname is not an accepted
value.
GL_INVALID_VALUE is generated if a specular exponent outside the range
[0,128] is specified.
ASSOCIATED GETS
glGetMaterial
SEE ALSO
glColorMaterial, glLight, glLightModel
GLMATERIAL(3G)
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