C SPECIFICATION
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
being 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 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 materi-
als 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 materi-
als 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 directly. Neither integer nor floating-
point values are clamped. The initial specular
reflectance for both front- and back-facing materi-
als 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 lin-
early such that the most positive representable
value maps to 1.0, and the most negative repre-
sentable 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 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
changed per vertex, however, glColorMaterial is preferred over
glMaterial (see glColorMaterial).
While the ambient, diffuse, specular and emission material parameters
all have alpha components, only the diffuse alpha component is used in
the lighting computation.
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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