Are NURB model used in games?

melviso

I just wanted to ask if Nurb models are used in games.I am thinking of making some NURB human models.
By the way,has anyone here tried Rhino3d,its a nurbs modelling software?

keres

NURBS are not rendered in games. They are helpful for rigging and some other helpers, but almost everyone uses polygons. Neither Direct3D or OpenGL can render NURBS. Any modeling program that allows you to work with them that uses one of those two converts the nurbs to polygons before rendering (this is true with all spline-based pieces of geometry.)

There are a few instances where NURBS are easier to work with than polygons, but it's not typical to use them exclusively, especially for a human model. ZBrush uses polygons, for obvious reasons.

wizzy886

I personally would say that nurbs are too hard for games to render even if they could. Since they are computer generated pieces of geometry and would be infinite in complexity. And that's not good with a budget game right?

cptSwing

I'd assume that some people model their high poly models using NURBS.. then again, i don't know of any and i'm not sure how "clean" the conversion to Poly meshes prior to baking might be..

Brendan

cptSwing wrote: »

I'd assume that some people model their high poly models using NURBS.. then again, i don't know of any and i'm not sure how "clean" the conversion to Poly meshes prior to baking might be..

I use them when making racetracks for a game I'm working on - lofting between curves allows me to easily define corner profiles, and change them and have the mesh auto-update for me.

Then when I'm happy with the track, just break it off the lofted shape, and it's already UV'd, it's as smooth as you're going to get and if you need to adjust the smoothness later it's easy as well.

Nurbs for a face might be a bit too much; the amount of control points you'd need would make it obsolete over straight poly sub/d modeling.

renderhjs

If you are doing engineering or industrial design NURBS are the only way to go - because there are clear advantages with them in those fields and they have been established.
On the other hand any real-time industry including games has been stuck with triangles all the way because that's how the hardware (GPU), frameworks, effects and everything around them have been developed over the years.
You sometimes see different approaches in games or interactive media like vector graphics (Flash), sprites (2d games) or Voxels but there is a clear trend in which more and more platforms are going GPU accelerated which means handling things with triangles in the end.

Also if you are modelling in Rhino or Moi3D what you see in the viewport is triangle 3D, they convert so to say every time you create a NURB patch or surface a cached 3D triangle mesh of it that is displayed using the GPU because its faster. But having lets say character made with NURBS and having them deform and update from within a NURBS structure would eat up to much performance because it would have to be converted per frame to a triangle mesh.

gray

the short answer is that subdivision surfaces have made nurbs obsolete. nurbs are a very old 1960 stab at making smooth organic limit surfaces. they were used in film because they rendered smooth in a software renderer. no need for real time there. but they have many limitations when you try to make complicated objects. subdiv surfaces fixed all those problems and give you a limit surface from euclidean geometry. so its win win win.

once in a while you still find a cranky old tard that learned nurbs and wants to inflict all the pain on you. they will defend nurbs and give you chestnuts about auto uvs etc. but don't be fooled! they just want you to be crippled in the pain that is nurbs modeling.

Ouija

Nurbs aren't used in games, but you can convert them to polys - which won't result in topology and polycounts as efficient as if you used polygons from scratch. You can correct these mistakes by hand, but that's almost as much work as doing polygons, so... I'd advise you to stick to simple shapes if you really want to use that.
Last time I saw curves used for graphics in games was Quake 3's engine. (and later Doom 3 I think) The engine converted curves to polygons on the fly, which resulted in easy to make, nice looking and fast to render (huge scaleability) architecture. (only downside being the lack of occlusion, but that was the level designer's problem)