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A collection of questions asked pretty often by new Maya users.


Thursday

NURBS vs Polygons vs Subdivision

Q: What are the differences between polygons, subdivisions and NURBS?


Polygonal, Subdivision, NURBS spheres from left to right


A:
Polygons are surfaces made up of faces, each face is an enclosure of edges, whether it be three edges, four edges, or more (n-gons). These surfaces can be made up of many faces, as many as your computer can handle or just a single face. Each edge runs in a straight line and the point where these lines meet is called a vertex. And since polygon edges flow in straight lines, they easily create hard, faceted surfaces but of course more faces are required to form smooth, curvy surfaces, effectively increasing the object's resolution or "poly count".  Of course, there is a polygon count threshold a given computer can handle before it starts to struggle. Many modern renderers have a feature that allows polygon objects to be smoothed at render time, this allows users to have lower counts for smoother, less hassling real time interaction. Poly objects can be combined and welded together, cut, sculpted, extruded, extracted, UV mapped etc.

 NURBS geometry is made of patches generated from curves. They easily form curvy rounded surfaces and placing points closer together enables the user to create sharper corners. These surfaces can be stitched together, trimmed, sculpted etc.

Subdivisional surfaces allow the user to focus on detailing regions instead of making the entire mesh heavier, hence the name subdivision. It feels like a hybrid of NURBS and polygons, easily generating smooth and rounded surfaces like NURBS while utilizing many polygonal tools.

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 So they are all capable of taking you to the same destination just using a different road, it's not uncommon for a modeler to convert back and forth between different geometry types. But at the end of the day it's all about your preference so try them all.

NOTEAs of Maya 2014 the subdiv surfaces tools have been removed from the Maya user interface, they are still available just hidden since the modeling method largely fell out of use.

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