Optionalfiletext: string | ArrayBufferOptionalfileName: stringOptionaladjustZtoY: booleanThe file's text for .step, .stp, .iges and .igs, or an ArrayBuffer for the compressed
.stpz and .igz forms.
The file name; its extension decides whether it is read as STEP or IGES and whether it is compressed.
When true, the shape is turned so the file's Z-up becomes this library's Y-up.
File content, a file name and an axis option for
io.loadSTEPorIGES, which reads STEP or IGES into a shape.