15bd8deadSopenharmony_ciName 25bd8deadSopenharmony_ci 35bd8deadSopenharmony_ci EXT_object_space_tess 45bd8deadSopenharmony_ci 55bd8deadSopenharmony_ciName Strings 65bd8deadSopenharmony_ci 75bd8deadSopenharmony_ci GLU_EXT_object_space_tess 85bd8deadSopenharmony_ci 95bd8deadSopenharmony_ciVersion 105bd8deadSopenharmony_ci 115bd8deadSopenharmony_ci $Date: 1996/04/12 125bd8deadSopenharmony_ci 135bd8deadSopenharmony_ciNumber 145bd8deadSopenharmony_ci 155bd8deadSopenharmony_ci 75 165bd8deadSopenharmony_ci 175bd8deadSopenharmony_ciDependencies 185bd8deadSopenharmony_ci 195bd8deadSopenharmony_ci None 205bd8deadSopenharmony_ci 215bd8deadSopenharmony_ciOverview 225bd8deadSopenharmony_ci 235bd8deadSopenharmony_ci This extension adds two object space tessellation methods for GLU nurbs 245bd8deadSopenharmony_ci surfaces. The existing tessellation methods GLU_PATH_LENGTH and 255bd8deadSopenharmony_ci GLU_PARAMETRIC_ERROR are view dependent since the error tolerance is 265bd8deadSopenharmony_ci measured in the screen space (in pixels), while the corresponding object 275bd8deadSopenharmony_ci space tessellation methods are view independent in that the error tolerance 285bd8deadSopenharmony_ci measurement is in the object space. 295bd8deadSopenharmony_ci 305bd8deadSopenharmony_ci 315bd8deadSopenharmony_ciNew Procedures and Functions 325bd8deadSopenharmony_ci 335bd8deadSopenharmony_ci None 345bd8deadSopenharmony_ci 355bd8deadSopenharmony_ciNew Tokens 365bd8deadSopenharmony_ci 375bd8deadSopenharmony_ci Accepted by the <value> parameter of NurbsProperty: 385bd8deadSopenharmony_ci 395bd8deadSopenharmony_ci OBJECT_PARAMETRIC_ERROR_EXT 100208 405bd8deadSopenharmony_ci OBJECT_PATH_LENGTH_EXT 100209 415bd8deadSopenharmony_ci 425bd8deadSopenharmony_ciErrors 435bd8deadSopenharmony_ci 445bd8deadSopenharmony_ci None 455bd8deadSopenharmony_ci 465bd8deadSopenharmony_ciAdditions to the GLU Specification Version 1.2, Section 7.6 475bd8deadSopenharmony_ci 485bd8deadSopenharmony_ci NURBS properties 495bd8deadSopenharmony_ci ---------------- 505bd8deadSopenharmony_ci 515bd8deadSopenharmony_ci GLU_SAMPLING_METHOD specifies how a NURBS surface should be tessellated. 525bd8deadSopenharmony_ci value may be set to one of GLU_PATH_LENGTH, GLU_PARAMETRIC_ERROR, 535bd8deadSopenharmony_ci GLU_DOMAIN_DISTANCE, GLU_OBJECT_PATH_LENGTH_EXT, or GLU_OBJECT_PARAMETRIC_ERROR_EXT. 545bd8deadSopenharmony_ci When set to 555bd8deadSopenharmony_ci GLU_PATH_LENGTH, the surface 565bd8deadSopenharmony_ci is rendered so that the maximum length, in pixels, of edges of the 575bd8deadSopenharmony_ci tessellation polygons is no greater than what is specified by 585bd8deadSopenharmony_ci GLU_SAMPLING_TOLERANCE. 595bd8deadSopenharmony_ci GLU_PARAMETRIC_ERROR specifies that 605bd8deadSopenharmony_ci the surface is rendered in such a way that the value specified by 615bd8deadSopenharmony_ci GLU_PARAMETRIC_TOLERANCE describes the maximum distance, in pixels, 625bd8deadSopenharmony_ci between the tessellation polygons and the surfaces they approximate. 635bd8deadSopenharmony_ci GLU_DOMAIN_DISTANCE allows the users to specify, in parametric 645bd8deadSopenharmony_ci coordinates, how many sample points per unit length are taken in u, v 655bd8deadSopenharmony_ci dimension. 665bd8deadSopenharmony_ci GLU_OBJECT_PATH_LENGTH_EXT is similar to GLU_PATH_LENGTH except that it is 675bd8deadSopenharmony_ci view independent, that is, it specifies that the surface is rendered so that 685bd8deadSopenharmony_ci the maximum length, in object space, of edges of the tessellation polygons 695bd8deadSopenharmony_ci is no greater than what is specified by GLU_SAMPLING_TOLERANCE. 705bd8deadSopenharmony_ci GLU_OBJECT_PARAMETRIC_ERROR_EXT is similar to GLU_PARAMETRIC_ERROR except 715bd8deadSopenharmony_ci that it is view independent, that is, it specifies that 725bd8deadSopenharmony_ci the surface is rendered in such a way that the value specified by 735bd8deadSopenharmony_ci GLU_PARAMETRIC_TOLERANCE describes the maximum distance, in object space, 745bd8deadSopenharmony_ci between the tessellation polygons and the surfaces they approximate. 755bd8deadSopenharmony_ci The default value of GLU_SAMPLING_METHOD is GLU_PATH_LENGTH. 765bd8deadSopenharmony_ci 775bd8deadSopenharmony_ci GLU_SAMPLING_TOLERANCE specifies the maximum distance, in pixels or 785bd8deadSopenharmony_ci in object space when the sampling method is set to GLU_PATH_LENGTH or 795bd8deadSopenharmony_ci GLU_OBJECT_PATH_LENGTH_EXT. The default value for GLU_SAMPLING_TOLERANCE 805bd8deadSopenharmony_ci is 50.0. 815bd8deadSopenharmony_ci 825bd8deadSopenharmony_ci GLU_PARAMETRIC_TOLERANCE specifies the maximum distance, in pixels or 835bd8deadSopenharmony_ci in object space when the sampling method is set to GLU_PARAMETRIC_ERROR 845bd8deadSopenharmony_ci or GLU_OBJECT_PARAMETRIC_ERROR_EXT. The default value for 855bd8deadSopenharmony_ci GLU_PARAMETRIC_TOLERANCE is 0.5. 865bd8deadSopenharmony_ci 875bd8deadSopenharmony_ci 885bd8deadSopenharmony_ci 895bd8deadSopenharmony_ci 90