Wednesday, 4 May 2011

NURBS- surface modelling in Maya

Recently I have had an introduction to NURBS, a different approach to 3D modelling that is to polygon modelling what vector graphics are to bitmap graphics. In short, NURBS rely on a series of plotted nodes, automatically joined together via a curve as smoothly as possible.

Everyone seems to like NURBS, which I suspect is because they have a funny-sounding name. People should try this with nasty boring things like maths- if it were called something amusing like 'wizzlefizzle' or 'smish', for example, I think people would like it a lot more. Anyway, for my first NURBS modelling exercise, I created a simple wine glass.

As you can see in the screenshot above, from a side view, I was able to plot nodes with a Bezier-like tool, joined with curves, to create the half-profile of the glass. The reason I created half is because it is possible to rotate the outline around a central pivot point, to create a full shape. This tool is especially useful for objects with this kind of radial symmetry, such as vases and bottles.

You will also have noticed from the image above that there are two glasses- the first having already been revolved, and the other just plotted. I quickly realised after finishing the first glass that whilst it looked good, it was hollow- the model had no interior surface, therefore had no thickness whatsoever. To improve on this, I tried a slightly different approach- to begin plotting nodes from the base, and to eventually continue this surface round and inside the glass.

You can see therefore from the comparison images above that the second glass is far more realistic than the first due to the fact that it has thickness and the hollow area does not continue into the handle and base- the difference is not too noticeable at first glance, but it does add a whole new level of detail to the work.

The clear ‘glass’ effect was created very simply by assigning a pale blue colour to the models, then increasing their transparency. 

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