Subdivision surfaces

[Alan Rockwood]

Can anyone explain subdivision surfaces for me? I understand that it involves modeling the surface by breaking it into smaller and smaller pieces, but what is the mathematical description of a subdivision surface? Preferably, explain it in plain language, maybe with a few well-explained formulas to illustrate key points.

Also, can Delftship export a NURBS equivalent or near-equivalent to a subdivision surface?

Thanks.

[Marven]

See the PDF document below for a mathematical description of a subdivision surface similar to the one used by Delftship.
As far as conversion from/to NURBS is concerned:

• Uniform non-rational Bspline surfaces can be presented by subdivision surfaces exactly
• Non-uniform or rational surfaces are approximated
• Conversion to NURBS is also exact

Attachments:

• 10.1.1.17.9381.pdf

[Alan Rockwood]

Thank you for the pdf Marven. I will try to read it and understand it.

[Liliana]

Marvin,

Thanks for the paper, I read it as well, but however im unsure of your previous statement. To clarify, are you saying that importing a NURBS surface into Delftship means that the surface would be approximated however exporting Delftship into NURBS would be exact?

Thanks so much for any help.

[Author]

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