该格式首次出现于 20 世纪 90 年代,其目的不仅是标准化 3D 内容,还标准化特定于工业用途的附加数据,例如公差和材料。 STEP 文件的标准被称为 ISO-10303-21 标准,多年来经过修订以支持更多功能。
STEP 文件中的 3D 数据使用由面、边缘和其他几何数据组成的形状组合以文本形式表示。如前所述,STEP 格式旨在成为 3D 模型交换的标准,这意味着它在 CAD 和 3D 建模应用程序以及文件转换软件中得到广泛支持。
000ISO-10303-21;
001HEADER;
002/* Generated by software containing ST-Developer
003 * from STEP Tools, Inc. (www.steptools.com)
004 */
005
006FILE_DESCRIPTION(
007/* description */ (''),
008/* implementation_level */ '2;1');
009
010FILE_NAME(
011/* name */ 'c5.stp',
012/* time_stamp */ '2024-02-05T06:35:35+00:00',
013/* author */ (''),
014/* organization */ (''),
015
016/* authorisation */ '');
017
018FILE_SCHEMA (('AUTOMOTIVE_DESIGN { 1 0 10303 214 3 1 1 }'));
019ENDSEC;
020
021DATA;
022#10=SHAPE_REPRESENTATION_RELATIONSHIP('SRR','None',#22544,#11);
023#11=ADVANCED_BREP_SHAPE_REPRESENTATION($,(#11436),#22538);
024#12=ORIENTED_CLOSED_SHELL($,*,#11433,.F.);
025#13=ORIENTED_CLOSED_SHELL($,*,#11434,.F.);
026#14=ORIENTED_CLOSED_SHELL($,*,#11435,.F.);
027#15=CONICAL_SURFACE($,#11713,0.59315625,0.759762754875772);
028#16=CONICAL_SURFACE($,#11720,0.59315625,0.759762754875772);
029#17=SPHERICAL_SURFACE($,#11545,0.01265625);
030#18=SPHERICAL_SURFACE($,#11591,0.050625);
031#19=SPHERICAL_SURFACE($,#11689,0.050625);
032#20=SPHERICAL_SURFACE($,#11742,0.050625);
033#21=TOROIDAL_SURFACE($,#12201,0.3290625,0.0759375);
034#22=TOROIDAL_SURFACE($,#12206,0.4809375,0.0759375);
035#23=TOROIDAL_SURFACE($,#12211,0.1771875,0.0759375);
036#24=(
037BOUNDED_SURFACE()
038B_SPLINE_SURFACE(2,2,((#16169,#16170,#16171,#16172,#16173,#16174,#16175,
039#16176,#16177),(#16178,#16179,#16180,#16181,#16182,#16183,#16184,#16185,
040#16186),(#16187,#16188,#16189,#16190,#16191,#16192,#16193,#16194,#16195),
041(#16196,#16197,#16198,#16199,#16200,#16201,#16202,#16203,#16204),(#16205,
042#16206,#16207,#16208,#16209,#16210,#16211,#16212,#16213),(#16214,#16215,
043#16216,#16217,#16218,#16219,#16220,#16221,#16222),(#16223,#16224,#16225,
044#16226,#16227,#16228,#16229,#16230,#16231),(#16232,#16233,#16234,#16235,
045#16236,#16237,#16238,#16239,#16240),(#16241,#16242,#16243,#16244,#16245,
046#16246,#16247,#16248,#16249)),.UNSPECIFIED.,.T.,.T.,.F.)
047B_SPLINE_SURFACE_WITH_KNOTS((3,2,2,2,3),(3,2,2,2,3),(-3.14159265358979,
048-1.5707963267949,0.,1.5707963267949,3.14159265358979),(0.,1.5707963267949,
0493.14159265358979,4.71238898038469,6.28318530717959),.UNSPECIFIED.)
050GEOMETRIC_REPRESENTATION_ITEM()
051RATIONAL_B_SPLINE_SURFACE(((1.,0.707106781186548,1.,0.707106781186548,1.,
0520.707106781186548,1.,0.707106781186548,1.),(0.707106781186548,0.500000000000001,
0530.707106781186548,0.500000000000001,0.707106781186548,0.500000000000001,
0540.707106781186548,0.500000000000001,0.707106781186548),(1.,0.707106781186548,
0551.,0.707106781186548,1.,0.707106781186548,1.,0.707106781186548,1.),(0.707106781186548,
0560.500000000000001,0.707106781186548,0.500000000000001,0.707106781186548,
0570.500000000000001,0.707106781186548,0.500000000000001,0.707106781186548),
058(1.,0.707106781186548,1.,0.707106781186548,1.,0.707106781186548,1.,0.707106781186548,
0591.),(0.707106781186547,0.5,0.707106781186547,0.5,0.707106781186547,0.5,
0600.707106781186547,0.5,0.707106781186547),(1.,0.707106781186548,1.,0.707106781186548,
0611.,0.707106781186548,1.,0.707106781186548,1.),(0.707106781186548,0.5,0.707106781186548,
0620.5,0.707106781186548,0.5,0.707106781186548,0.5,0.707106781186548),(1.,
0630.707106781186548,1.,0.707106781186548,1.,0.707106781186548,1.,0.707106781186548,
0641.)))
065REPRESENTATION_ITEM($)
066SURFACE()
067);
由于基于文本的格式,将复杂的 3D 数据保存为该格式时,STEP 文件可能会变得非常大。 STEP 文件也可能需要一些时间才能加载到编辑软件中,因此在编辑这些文件时请留出更多时间。