I am experiencing a critical issue when opening a specific STEP file (157f8ef244231cb5305051c293e4ec2d.stp) in Rhino.
Problem: When I directly open the attached STEP file in Rhino (File → Open), the object appears only as a 2D circle/disk, which represents the base of a cone. The conical surface itself is missing entirely.
The same behavior occurs when importing the file programmatically via RhinoDoc.Import() in a C# plugin.
Attaching the STEP file below:
ISO-10303-21;
HEADER;
/* Generated by software containing ST-Developer
from STEP Tools, Inc. (www.steptools.com)
*/
FILE_DESCRIPTION(
/* description / (‘’),
/ implementation_level */ ‘2;1’);
FILE_NAME(
/* name / ‘157f8ef244231cb5305051c293e4ec2d.stp’,
/ time_stamp / ‘2026-06-02T15:43:40+05:30’,
/ author / (‘’),
/ organization / (‘’),
/ preprocessor_version / ‘ST-DEVELOPER v20.1’,
/ originating_system / ‘ATF’,
/ authorisation */ ‘’);
FILE_SCHEMA ((‘AUTOMOTIVE_DESIGN { 1 0 10303 214 3 1 1 }’));
ENDSEC;
DATA;
#10=MECHANICAL_DESIGN_GEOMETRIC_PRESENTATION_REPRESENTATION(‘’,(),#57);
#11=SHAPE_REPRESENTATION_RELATIONSHIP(‘SRR’,‘None’,#63,#12);
#12=ADVANCED_BREP_SHAPE_REPRESENTATION(‘’,(#13),#56);
#13=MANIFOLD_SOLID_BREP(‘’,#33);
#14=PLANE(‘’,#37);
#15=FACE_OUTER_BOUND(‘’,#17,.T.);
#16=FACE_OUTER_BOUND(‘’,#18,.T.);
#17=EDGE_LOOP(‘’,(#26,#27,#28));
#18=EDGE_LOOP(‘’,(#29));
#19=CIRCLE(‘’,#36,152.4);
#20=LINE(‘’,#51,#21);
#21=VECTOR(‘’,#42,76.2);
#22=VERTEX_POINT(‘’,#49);
#23=VERTEX_POINT(‘’,#50);
#24=EDGE_CURVE(‘’,#22,#23,#20,.T.);
#25=EDGE_CURVE(‘’,#23,#23,#19,.T.);
#26=ORIENTED_EDGE(‘’,,,#24,.T.);
#27=ORIENTED_EDGE(‘’,,,#25,.F.);
#28=ORIENTED_EDGE(‘’,,,#24,.F.);
#29=ORIENTED_EDGE(‘’,,,#25,.T.);
#30=CONICAL_SURFACE(‘’,#35,76.2,0.165148677414627);
#31=ADVANCED_FACE(‘’,(#15),#30,.T.);
#32=ADVANCED_FACE(‘’,(#16),#14,.T.);
#33=CLOSED_SHELL(‘’,(#31,#32));
#34=AXIS2_PLACEMENT_3D(‘’,#47,#38,#39);
#35=AXIS2_PLACEMENT_3D(‘’,#48,#40,#41);
#36=AXIS2_PLACEMENT_3D(‘’,#52,#43,#44);
#37=AXIS2_PLACEMENT_3D(‘’,#53,#45,#46);
#38=DIRECTION(‘axis’,(0.,0.,1.));
#39=DIRECTION(‘refdir’,(1.,0.,0.));
#40=DIRECTION(‘center_axis’,(0.,0.,-1.));
#41=DIRECTION(‘ref_axis’,(1.,0.,0.));
#42=DIRECTION(‘’,(-0.164398987305357,-2.01330693586572E-17,-0.986393923832144));
#43=DIRECTION(‘center_axis’,(0.,0.,-1.));
#44=DIRECTION(‘ref_axis’,(1.,0.,0.));
#45=DIRECTION(‘center_axis’,(0.,0.,-1.));
#46=DIRECTION(‘ref_axis’,(-1.,0.,0.));
#47=CARTESIAN_POINT(‘’,(0.,0.,0.));
#48=CARTESIAN_POINT(‘Origin’,(-1828.8,-1828.8,457.2));
#49=CARTESIAN_POINT(‘’,(-1828.8,-1828.8,914.4));
#50=CARTESIAN_POINT(‘’,(-1981.2,-1828.8,0.));
#51=CARTESIAN_POINT(‘’,(-1905.,-1828.8,457.2));
#52=CARTESIAN_POINT(‘Origin’,(-1828.8,-1828.8,0.));
#53=CARTESIAN_POINT(‘Origin’,(-1828.8,-1828.8,0.));
#54=UNCERTAINTY_MEASURE_WITH_UNIT(LENGTH_MEASURE(0.001),#58,
‘DISTANCE_ACCURACY_VALUE’,
‘Maximum model space distance between geometric entities at asserted c
onnectivities’);
#55=UNCERTAINTY_MEASURE_WITH_UNIT(LENGTH_MEASURE(0.001),#58,
‘DISTANCE_ACCURACY_VALUE’,
‘Maximum model space distance between geometric entities at asserted c
onnectivities’);
#56=(
GEOMETRIC_REPRESENTATION_CONTEXT(3)
GLOBAL_UNCERTAINTY_ASSIGNED_CONTEXT((#54))
GLOBAL_UNIT_ASSIGNED_CONTEXT((#58,#59,#60))
REPRESENTATION_CONTEXT(‘’,‘3D’)
);
#57=(
GEOMETRIC_REPRESENTATION_CONTEXT(3)
GLOBAL_UNCERTAINTY_ASSIGNED_CONTEXT((#55))
GLOBAL_UNIT_ASSIGNED_CONTEXT((#58,#59,#60))
REPRESENTATION_CONTEXT(‘’,‘3D’)
);
#58=(
LENGTH_UNIT()
NAMED_UNIT()
SI_UNIT(.CENTI.,.METRE.)
);
#59=(
NAMED_UNIT()
PLANE_ANGLE_UNIT()
SI_UNIT($,.RADIAN.)
);
#60=(
NAMED_UNIT(*)
SI_UNIT($,.STERADIAN.)
SOLID_ANGLE_UNIT()
);
#61=SHAPE_DEFINITION_REPRESENTATION(#62,#63);
#62=PRODUCT_DEFINITION_SHAPE(‘’,$,#65);
#63=SHAPE_REPRESENTATION(‘’,(#34),#56);
#64=PRODUCT_DEFINITION_CONTEXT(‘part definition’,#69,‘design’);
#65=PRODUCT_DEFINITION(‘157f8ef244231cb5305051c293e4ec2d’,
‘157f8ef244231cb5305051c293e4ec2d’,#66,#64);
#66=PRODUCT_DEFINITION_FORMATION(‘’,$,#71);
#67=PRODUCT_RELATED_PRODUCT_CATEGORY(‘157f8ef244231cb5305051c293e4ec2d’,
‘157f8ef244231cb5305051c293e4ec2d’,(#71));
#68=APPLICATION_PROTOCOL_DEFINITION(‘international standard’,
‘automotive_design’,2009,#69);
#69=APPLICATION_CONTEXT(
‘Core Data for Automotive Mechanical Design Process’);
#70=PRODUCT_CONTEXT(‘part definition’,#69,‘mechanical’);
#71=PRODUCT(‘157f8ef244231cb5305051c293e4ec2d’,
‘157f8ef244231cb5305051c293e4ec2d’,$,(#70));
ENDSEC;
END-ISO-10303-21;
