Microsoft Knowledge Base

Normals May Be Inversed When Curves are Drawn Clockwise
Last reviewed: September 3, 1996
Article ID: Q153879
The information in this article applies to:
  • Softimage 3D for IRIX, version 3.50

SUMMARY

When performing either Surface->Extrusion or Surface->Revolution in the Softimage 3D Model module, draw all the curves counter-clockwise; otherwise, the normals in the resulting model might be inversed. Inversed normals cause Softimage 3D to read the model inside out, which means the light source is perceived to be on the inside of the model, and the model does not show up in either the Perspective window, the Shade preview, or the Softimage 3D Matter module Preview.

If, for this or any other reason, your model's normals are inversed, use the Effect->Inverse function in the Model module to reorient them to the surface of the model.

REFERENCES

"Softimage 3D Reference Guide: A to H," Interface, Effect->Inverse, pages 429-430

"Softimage 3D Reference Guide: I to Z," Appendices, Surface->Extrusion, pages 1346-1350

"Softimage 3D Reference Guide: I to Z," Appendices, Surface->Revolution, pages 1351-1354

"Softimage 3D Modelling User's Guide," Normals, page 7

If you have any questions concerning the information contained in this article, contact support@softimage.com by e-mail.

NOTE: Softimage Inc. is a wholly owned subsidiary of Microsoft Corporation.

Additional reference words: 3.50
KBCategory: kbgraphic
KBSubcategory: si si3d si3dmo



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Last reviewed: September 3, 1996
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