Does anyone use NURBS for modeling here? If you do, what do you use them for?
Adding to anon's statement here.
Curves are used to express organic hard-surfaces in the most simple way. They are used to express natural form in a mathematical way.
I would guess right if I said NURBS has no place in games, right?
I use it in Rhino all the time. They're amazing in design, prototyping and architecture if you know what to do with them.
The one downside so far is that you can't convert them to a proper mesh with good topology... yet.
Not yet, but I hear quad meshing is coming soon. That'll change a lot.
>Not yet, but I hear quad meshing is coming soon. >That'll change a lot.
No anon, it won't. Quads don't even exist in your DCC packages, they only LOOK like quads because our software hides the edge that normally splits up the quad into to triangles. This edge's orientation changes depending on how the 4 corners of the quad are oriented and is automatically split to two triangles when sent to our GPUs.
Look at this image. All 3 are quads. The two on the right have nearly the same vertex position, yet one is convex and one is concave, even though I have no defined an edge in the middle to determine that. The software is simply guessing which way is best to split the quad for you unless you explicitly define it. And since we don't explicitly define it, we're able to use tools that can follow edge-flows because they can simple be told to ignore this part of the process.
Triangles are the fastest way to do math on a complex surface, because we know that a triangle will always be perfectly flat and we can also use the tricks of trigonometry.
Having to compute that internal edge on every single quad in your game-scene would induce a MASSIVE performance overhead.
NURBS cannot be UV mapped. Texturing them can only really be done in procedural ways that are generally ugly. And NURBS are only good for representing smooth, hard surfaces. A NURBS surface is actually tessellated into geometry to render onto your screen. So for games, we don't need to bother with NURBS, we can simply use tessellation and displacement to get the same level of smoothness, but with the great capabilities of rigging, texturing and animation.
When I said quads I meant usable topology with a decent flow that produces uniformly distributed planar polys whereas right now the only settings we have affect the tri density.
I've seen the recent improvements in poly-to-NURBS and NURBS-to-poly and the results are looking better and better with less human input.
Even right now you can do something like NURBS->mesh->ZBrush->decimate->retopo and get acceptable results.
Keep in mind that since NURBS aren't made for organic surfaces it's not that hard to get something decent out of it.
modelling, nothing. But since they are mathematically perfect and lack stepping they make for excellent smooth camera paths in animations.
If you gonna have a camera move trough a scene, don't use splines - use a NURBS curve instead.
NURBS for 3D Printing, Design prototypes, anything where measurements must be exact (engineering etc)
Polys for the rest.
people still use nurbs to get a basic shape of cars, planes, boats ect. it makes getting the initial shape that you can draw quads over to help speed up the block in process