# Whats the Diff???

Can sombody tell me what the difference between NURBS and Meshes are. I only use meshes, are there things you can do with NURBS that you cant do with meshes???
I know it sounds dumb.
can sombody tell me?
thanks

Nurbs do curves better. Ever try to take like a small tube and make an S with it in mesh? Pain moving all those verts and hard to get them all nicely lined up. With a nurb it takes like 2 seconds.

Also say you have a 2d picture of a curvy object you want to make into a 3d model. Imagine trying to follow an outline vert by vert and get those curves perfectโฆ You can take a nurbs curve and do it in no time flat.

the main difference is the maths behind (which i donโt understand ). what i know is that nurbs are ALWAYS patch grids, and each part is a quad. those quads can be bent to make spheres, tubes, donuts and more complex shapes, but you can always unfold them and what remains is a quadrangular surface. the problem with nurbs is that you can not locally subdivide them, e.g. make triangles at some place and add a denser mesh there. if you need higher subdivisoin at one place, the whole NURBS surface has a higher subdivision.

high-end nurbs modellers use tricks like trimming, surface blending etc. to allow more complex shapes.

the advantage of nurbs is precise geometry, which is required by applications like CAD/CAM, in the automotive industry (for modelling car parts) and such.

I think nurbs are also supposed to be better for displacement mapping since each patch is subdivided evenly automatically. Whereas a mesh can be very dense in some areas and only a few polygons in others.

well, this is the great advantage of polys. some sort of adaptive displacement is surely more effective than a high subdivisioin everywhere. why render millions of polys while a couple of 10 thousands will deliver the same result?