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Zaldron - Question - http://www.doomworld.com Forums


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Dima



alexsok@netvision.net.il
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"Zaldron - Question" , posted Fri 1 Jun 12:08:user profileedit/delete messagepost reply


Zaldron, first thing I want to ask you, how did you know that NURBS were present in the new doom engine demonstration on MacWorld in Tokyo?

Second thing I want to ask you, I remember you telling me that it is very hard to do NURBS on characters, do you think NURBS were present on the characters in the new doom engine demonstration?
If they weren't, do you think id will add them in the future? (the engine seems to be able to handle just about everything).

"We've been doing hacks and tricks for years but now we'll be able to do things we've been wanting to do for a long time" Carmack said. "For instance every light has its own highlight and every surface casts a shadow like in the real world". "Everything can behave the same now and we can apply effects for every pixel."

[this message was edited by Dima on Fri 1 Jun 12:09]

 

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Lord FlatHead



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"Re(1):Zaldron - Question" , posted Fri 1 Jun 13:40user profileedit/delete messagepost reply


Here's an additional question from me... I still don't really understand what NURBS is. What's the difference between them and the bezier patch curves of games like Quake III Arena ? And why do you see them as so important ?

--
"Well... I like to think I'm pretty good at what I do." -- John Carmack

http://lordflathead.doomcenter.com

 

 

Zaldron
Le Ventilateur



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"Re(2):Zaldron - Question" , posted Fri 1 Jun 14:07user profileedit/delete messagepost reply


Actually, NURBS aren't working there except the most crappy one, ussually called bezier patches.

Bezier patches come in 2 flavors, planes and uncapped cylinders.

Hardware isn't able to operate NURBS yet, because of their complexity. A NURBS could be just a plane, but it can also take the shape of an entire monster or a toilet.

A NURBS, it doesn't matter wich kind, is a set of PERFECT surfaces that aren't composed of triangles. They can be bended, twisted and folded without loosing their soft edges. You can connect them with other NURBSs and that's what most modelers use for creating characters in programs like MAX.
When it comes to rendering, there are several ways to do it. You can transform this theorical surfaces to so many triangles it will look round. Or to less triangles in order to mantain framerate. You can even use phong shading to render them, and that's the critical rendering style that isn't available in today's tech.

With that method, each visible pixel of the surface is rendered perfectly. Much like the lighting system, but there's no support.

Why not? The calculations. So far we have optimized support for simple bezier patches (that in conjunction can do great things), rendered as a LOD-dependant amount of triangles.

If I wrote "NURBS" in the article and never mentioned "bezier patches", then I'm an idiot. Cause NURBSs as the complex surfaces/volumes aren't there.

This patches are important as hell, because every CV (or control vertex) across the surface is designed with "soft-selection". WTF that means? It means that if you move one of these points, the others will gradually follow it, distorting the mesh to give a curved, smooth result. Move a vertex in a regular brush and you'll get a spike, or a pyramid, or things like that, hard and defined.

Since the "quality" NURBSs aren't supported, there's no fucking way you can model creatures, and let's not talk about animating them.

The reason why I see them so important are obvious. Just take a look at the video. There's a sequence where you can see a camera rotating around a brownish installation. Everything from the structure of the middle to the stairs railling are done with bezier.

__________________________ _ _ _
"There are three kinds of death in this world. There's heart death there's brain death and there's being off the network."

 

 

Dima



alexsok@netvision.net.il
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"Re(3):Zaldron - Question" , posted Fri 1 Jun 14:17user profileedit/delete messagepost reply


But Zaldron, I've been told that NURBS are not present in the new doom engine, nor on the characters, nor on the enviroments.

"We've been doing hacks and tricks for years but now we'll be able to do things we've been wanting to do for a long time" Carmack said. "For instance every light has its own highlight and every surface casts a shadow like in the real world". "Everything can behave the same now and we can apply effects for every pixel."

 

 

Zaldron
Le Ventilateur



avengerz66@hotmail.com
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"Re(4):Zaldron - Question" , posted Fri 1 Jun 17:30user profileedit/delete messagepost reply


Fred Nilsson said he's not using them for model meshes, and that's believable.

If you say "NURBSs" then he will not understand. Try with bezier patches. If Q3A had them, how come DoomM3 don't? Simple logic.

If someone thought real NURBS were implemented by reading my article, then it's my fault. I meant bezier patches only. I'll correct that too.

__________________________ _ _ _
"There are three kinds of death in this world. There's heart death there's brain death and there's being off the network."