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GLMATERIAL(3G)				  OpenGL Manual 			   GLMATERIAL(3G)

NAME
       glMaterial - specify material parameters for the lighting model

C SPECIFICATION
       void glMaterialf(GLenum face, GLenum pname, GLfloat param);

       void 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 glMaterialfv(GLenum face, GLenum pname, const GLfloat * params);

       void 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 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 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 values specifying the color indices
	   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 the
	   glLightModel() reference page for a discussion of color index lighting.

NOTES
       The material parameters can be updated at any time. In particular, glMaterial can be
       called between a call to glBegin() and the corresponding call to glEnd(). If only a single
       material parameter is to be 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()

COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI
       Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

AUTHORS
       opengl.org

opengl.org				    06/10/2014				   GLMATERIAL(3G)
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