Slashdot Mirror
Voxel/Polygon Accelerator
G. Waters writes: "Ars Technica writes that "3DLabs and Real Time Visualization have teamed up to design an accelerator that accelerates both voxels and polygons in the same scene." A link to the announcement can be found here. Perhaps voxels will become more mainstream with similar developments." I'm still waiting for the cards with accelerated bezier patches, but this is cool too. *grin*
I'm pretty sure he used dict which checks quite a few dictionaries including Websters, the jargon file, and the gazetteer.
Pixels and voxels are zero-dimensional samples of some 2D image or 3D volume. Thinking about them as squares, gaussian splats, or something other than samples is the path to the Dark Side.
For more info, read Alvy Ray Smith's Tech Memo, "A Pixel is Not a Little Square, a Pixel is Not a Little Square, a Pixel is Not a Little Square! (And a Voxel is Not a Little Cube)" available here.
Really pisses me off when people forget that the ACCLERATOR is on the RIGHT.
/. is hosted in the US, but hackers from other countries read it to you know.
Over here, the ACCELERATOR is on the left. I know
I agree. Novalogic made a great game with this technology. Nearly all of the reviews I've read have suggested that it would be an exceptional "if only" it had used a polygon engine. Much advancement has been made with polygons, so it's easy to compare a relatively mature technology with one that is being freshly implemented into a field it has not been initially intended for. Have any of you guys seen DF2 at 1024x768? The terrain looks gorgeous. The frame rate (at least on my system) is unplayable, but so would a unaccellerated polygon scene with the same level of detail and distance. Keep in mind that the maps in DF2 are rendering 2000+ meters of visibility, including grass, stones, and special textures like railroad tracks (made with voxels and not polygons). To do all of this, while rendering misc. polygon objects at an acceptable frame rate @ 640x480, without acceleration, seems to show just how valuable this technology could be with a little advancement. The fact that this announced graphics card will support both polygons and voxels seems to make this a technology we really should be talking more about. G. Waters "Sigs Cause Cancer"
My under educated opinion is that a subdivision surface scheme would make more sense than a NURBS or Bezier Patch one both from a modeling and a hardware implementation point of view. There was an interesting paper (http://24.19.151.16/RI_DSS.html) in the subdivision session at Siggraph this year which describes a technique the presenter claimed will be useful for a hardware implementation (this was supposedly in contrast to a similar paper which followed his in the same session: http://www.cs.caltech.edu/~ivguskov/papers.html#no rmalmeshes).
There are 10 kinds of people: Those that understand ternary; those that don't; and those that don't care.
I think you mean "vowels," No? :)
-Vercingetorix
-Vercingetorix
"Necessitas non habet legem." -St. Augustine
The chip can do 256^3 at 20fps. Larger sized volumes can be held on the board (current board has 256MB ram) and is handled transparently by the library they supply. So, you probably have nothing to worry about. I routinely use 512^3 volumes and get maybe 4 frames per second. I would guess future boards would support larger volumes and be faster at doing it.
I know the Edge 3d had one version with hardware Sega Genesis emulation. The saturn was very similar to the genesis (backwards compatible, i believe?) so I think you're right on that....
Walter H. Trent "Muad'Dib"
Padishah Emperor of the Known Universe, IMHO
Oops. Please make that ~1 fps for 512^3.
Can't anybody read english anymore?
he said: Really pisses me off when people forget that the ACCLERATOR is on the RIGHT.
So it pisses him off when people FORGET that the accelerator IS on the right.
Should I repeat that? He is stating that the accellerator is on the right, but some people forget about that from time to time, and that pisses him off.
He was trying to be humerous.....
Johan V.
Basically for everything but the landscape.
But it used bumpmapping and anti-aliasing so those looked quite nice for software too.
Genesis emulation? Possible, but why?
The saturn hardware has dual hitachi CPUs. The genesis used a 68000 chip. Now, there was an upgrade for the genesis that plugged into the cartidge slot, and then cartridges went into this thing. I forget the name, but it also had dual hitachi CPUs, but they were slower.
The dual CPUs is why the saturn flopped. The PS also has dual CPUs, but the software library that came with it took advantage of that. The software libraries that came with th Saturn didn't, so programmers had to balance their program across both CPUs themselves. This meant that the initial games only used a little over 50% of the power available, whereas the initial PS games used over 80% of the available power.
Also, the second CPU of the PS had the same core instructions, but the stripped parts of it and added some other parts, so the stuff they added might have given it an additional edge. Well, that's what I heard at least. The docs I'm able to find aren't clean whether that second chip is a modified r3000 or if it is totally different, and I'm not familiar with the r3000 to tell just by looking at the instruction sets.
-- Superlame http://catpro.dragonfire.net/joshua/
Supporting voxels for things like medical imaging is good, but I don't think it's such a big thing for games. Yes, voxels can be used for landscapes, and even characters. But do we even need that third dimension of resolution? When I'm playing a game, I don't see through a character, so wouldn't it be a waste to define elements inside the character? (Though a neat trick there would be to define his guts so shooting him would reveal them at any level of penetrati--Geez, I'm disturbed. There are other ways of doing that anyway.)
A landscape could be defined with things like curved surfaces and probably be much more efficient. From what I understand about 3D graphics, using voxels to store something like a 3D object as opposed to polygons is akin to using a huge array instead of a linked list to store data in memory.
so..umm...what is one? you seem to know... What advantages do they provide? What are nurbs and what do they provide?
---
no, not apache the web server, but a helicopter-sim game for the PC several years ago, had voxel-based rendering. I remember the lead programmer saying that they had constructed simple shapes for the landscape, then used an erosion simulator to wear away the voxels. Take a flat surface, run a "river" through it, and calculate which voxels are removed. That's something you can't really do with polygons.
It generated much more realistic landscapes than anything else at the time. Does anyone remember the title?
Pointless unless you're gaming or rendering...
On the contrary, i use voxels for word processing.
--
--
Mod up a post Rob doesn't like and you'll never mod again
While perusing other issues, I recall reading about a voxel-based 3/4 view helicopter game made for the Amiga. It sounded quite interesting, because it also allowed for realtime landscape deformation. You could blow a huge hole in the ground to force the enemy someplace else where you had a more strategic advantage. It sounded quite neat. I also can't remember the name. Plus I'm not even sure it's what you're talking about ;)
Just thought I'd share...
I'm waiting for the hardware companies to start using more intelligent bus systems like I2O (over PCI or multiple AGP) to allow for new and improved systems.
For gamers, this could mean a 3D card that stores scene description data and allows the sound card and video card to intercommunicate with it, doing co-rendering (one card handles the scene itself as a mathematical entity, the others handle mapping the sounds and/or images).
These types of interactions between hardware are difficult because of competition, of course.
- Michael T. Babcock (Yes, I blog)
don't flame, I don't game...
there's not too much point to accelleration. memory yes, but accelleration for desktop machines that are used for practical purposes besides rendering is worthless... I think we're going to hit critical i-dont-care faster with video cards than with cpus.
critical i-dont-care being the point where it doesn't matter anymore what is in your system
______
everyone was born right-handed, only the greatest overcome it.
http://leftorium.net
And that's where the high powered cpus everyone claims no one needs come in.
:)
For everything that no one needs, it has a complement that everyone says the same about
--
Pixel: picture-element
texel: texture-element
voxel: volume-element
Have a nice day!
-----
Obviousness is always the enemy of correctness. -- Bertrand Russell
Its meant to render a 256^3 voxel set in real time with full transparancy, not to quickly render a displacement mapped surface... which I agree is very usefull and has bugger all to do with voxels.
This chip has near zero relevance to gaming.
In any case, show me a monitor that does correct 2D reconstruction of an image from these samples. Can't? That's because it doesn't exist. In 1D audio processing there are known ways to reconstruct the 1D "image" given the samples. There is no such postprocessing on any modern monitors. And all this image processing stuff tacitly assumes there is. Ergo, again, it is not applicable.
To ram the point home, remember that "little square" and "sample" are just two MODELS of limited applicability in different situations. Mankind DOES NOT HAVE a model for image processing which is in any way "correct".
Calling it the "path to the Dark Side" is just silly.
--
It's a
-- Danny Vermin
Seriously, the use of polygons in graphics have not really done games any favours. Instead of having slow, but textured, graphics, we now have fast but clumsy & low-res graphics, instead.
IMHO, I'd rather have the quality than the quantity.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
No, it helps you stop being French more quickly.
Instead of knocking out the cobwebs, I will give you the links that I learned from.
bezier patches
Bezier curves
Nurbs
What it boils down to is an easy way to store a curved data set. The display part is trickier... and that is where the acceleration would be nice.
If you had a curved object, you could break it into poly's and have all the triangle points stored in memory or you can have the control points (and the weights if used) stored in memory.
Obviously the math for the poly's are faster but the display isn't as smooth (Such as Quake 2). With bezier patches, the display takes more math but is smoother because you are representing curves and not lines.
When it is all said and done, the math isn't too bad, it is just additional math that needs to be done at 30+ fps.
-I just work here... how am I supposed to know?
The fact you haven't heard the term "voxel" before is more an indicator of your ignorance than anything else. The term voxels goes back at least twenty years, if not thirty.
--
It's a
-- Danny Vermin
And Comanche 3 runs splendidly on a Pentium 166. ;) :) and they were all pretty fun, C3 probably the most, because of the afore-mentioned "popping up out of canyons and blasting off a couple hellfires" or whatever. Uh, oh, anyways, Novalogic really comes out with some decent games. If I only had a newer computer... Deltaforce 2 doesn't really run well on my computer :\
Warning: Some Rambling follows
C3 run's decent on my P75 laptop with a 2 meg video card too, of course with detail turned down. I purchased Commanche 3, Armored Fist 2 (another nice game using the same graphics engine) and F-22 Lightnight II (which used the graphics engine too) for like $30 in a package called "The Art of War" I believe. This turned me on to Novalogic (www.novalogic.com as someoen pointed out earlier I believe). That prompted me to buy Delta Force, which again used the graphics engine. DF came bundled with F-22 Raptor, which I'm not completely sure if it's the same graphics engine or not. Anyways, multiplayer on DF is really decent, the distance the terrain can get mapped too makes it really nice for long-range combat. If only it didn't lack weapons. I played F-22 Raptor multiplayer on the net a couple times too, although most of the time I was flying a parachute. The original three games, AF2, C3, F22 Lightning, I played them all over my home network (two or three people at a time depending on which computers were working
It's interesting to note that bilinear filtering and trilinear filtering are exactly the proper point sampling scaling techniques now implemented in all 3D cards that this fellow talks about when discussing how images should be scaled up for use on a monitor.
Think how much better textures look in Quake 2 and 3 when they are properly sampled with their neigbours and blended for use on the walls, rather than just pixel replication (like walking up to a wall in Doom and seeing a square of some ugly, solid) colour. Although there are still other ways to make the image quality look worse (compare how the blood/smoke clouds look on a Voodoo2 or a Voodoo5 vs. the square-ish-grid-look that seems to be inside them on an nVidia chipset [at least on the NV3, NV4, and NV5 chips ]:-)).
---
--
Internet Explorer (n): Another bug -- that is, a feature that can't be turned off -- in Windows.
Voxels are interesting because, once you get to a certain resolution using triangles, most of them project to be about 1 pixel large (or less) on the screen anyway. The idea is that using a cloud of points, for high density images you can get equal or nearly equal image quality with less data (it theoretically takes more data, and processing time, to handle a structured triangle mesh than it does a cloud of points).
.plan file 1.5 or 2 years ago about why he thinks Bezier patches are a bad idea and I pretty much agree with him. For the amount of data it takes you to create the shapes you want with Bezier patches, you can construct triangle meshes for the same shapes using less data and less headache.
At SIGGRAPH this year there were a number of papers about direct point rendering. (And also about lightfield rendering, which is about drawing scenes without using any geometry at all). Try digging up the proceedings if you are interested in this.
Hardware accelerated Bezier patches are a lot like hardware accelerated Phong shading: they sound like a great idea, the "obvious next step", unless you're trying to use them to do something real. Just as Phong shading is not a particularly interesting lighting model once you reach a certain level of sophistication, Bezier patches are not very interesting shapes. Yeah, they're curvy, but they are curvy *without surface detail at a higher resolution than the curve*, which is just not very interesting.
John Carmack had a
Jonathan Blow
Game Research Scientist
Bolt Action Software
To stay on topic, this accelerator IMHO represents a fairly significant advance in graphics hardware (not that it's new, but that it represents an intent to bring the hardware closer to the consumer market). As good as textured/lit/AA/bumpmapped/envmapped polys look, people need to remember that they're still just approximations. Take any polygonal/curved object, and keep increasing the resolution of detail. Eventually you're going to end up with just vertices. So while those approximations are the hip and in thing now, it's important to remember that eventually they will no longer be sufficient.
It should also be noted that when they say "voxels" they are talking about actual volume data, meaning a 3d array of samples. Delta Force/Commanche/Bladerunner/Tiberian Sun are all 2d simplifications.
Just take my word that I'm funny
You're right, it's not the basic unit, but there's evidence that one of the basic elements of visual perception is a 2D sine wave. The receptive fields of some neurons in the human visual cortex can be modeled using Gabor functions, which consist of a plane wave and a Gaussian function. This model is useful in describing and modeling patern perception and edge detection.
A lot of the posts thus far have focused on how cool (or how useless) such a thing would be for games. Though the press release doesn't specifically state it, you can count on cards using this technology to costs thousands if not tens of thousands of dollars at first. This is more for desktop medical imaging, etc than for games. Of course, as with all things, I'm sure the price will come down and it will eventually find mainstream usage...but that is likely years off.
..and that this was a Novalogic game. I remember almost having a seizure when I saw this running on a 486 for the first time.
Novalogic have recent received a new patent on their use of Voxels for rendering realtime 3d terrains (see also this patent, or here).
IIRC, the big problem with the use of voxels in the past is that Novalogic have actively enforced their patent, which has made many games companies reluctant to use voxels in games (to represent terrain, in any case. Bladerunner used voxels to represent characters, IIRC). Hardware acceleration may be good, but I'm wondering how many games companies will take advantage of the technology. From the Yahoo article it sounds like the technology is going to be aimed at the professional marketplace anyway.
In my own opinion, voxels are great for representing distant terrain, but they look horrible at short range (not to mention the memory requirements needed to represent a detailed scene with voxels). With today's TnL acceleration, polygon based scenery is more likely to provoke the response I had when seeing Comanche for the first time.
Why don't you just shut your pie hole.
There is nothing wrong with finding and posting useful information. Isn't that the point of allowing people to post here?
they are i believe two different methods of providing for curved surfaces. bezier curves for instance are use in q3:a. but i think its quite meaningless to provide acceleration for them, because current geometry acceleration [geforce 1,2, mx] *i believe* does that already. hope i could help.
#define GLAMATRON_IS_NOT_AN_EXPERT
#include <grain_of_salt.h>
/* hopefully if I got it wrong, someone will correct me */
I believe NURBS is an acronym for Non-Uniform Reticular B-Splines. B-Spline in turn is, I think, bilinear spline. Bilinear I think means that it's got 2 dimensions in which it extends. Of course, since it's curved, it takes up 3 dimensions.. like a piece of cloth. Whereas a normal spline would be like a piece of string. Bezier curves are a form of spline. I would guess that bezier patches are the 2D extension thereof.
Anyway, splines are a mathematical way to describe smooth curves that change direction a lot. (well, I guess you _could_ describe a hyperbola with splines, but you'd be better off just saying x = 1/y) So, when you take the spline model and extend it into 2 dimensions, you can make nifty curved surfaces like automobile bodies or rippled water or flux capacitance diagrams.. all with a relatively low number of control points.
Of course, the process of turning a bunch of control points into a matrix of really small triangles takes quite a bit of floating point math.. so it would be way cool for it to be accelerated in hardware. What would be even cooler would be for the hardware to translate it directly into hundreds or thousands of projected pixels.
"Jon" Carmack ?
At LEAST spell his name right. "John Carmack"
nf
It's an older voxel-based game with polygon buildings and vehivcles. The terrain is very well shaped though it's low on detail by today's standards. I especially like the desert missions where you're sneaking through canyons and popping up to fire off a few Hellfires... This sort of terrain really worked well with voxels. And Comanche 3 runs splendidly on a Pentium 166. (Now if only they hadn't implemented bag-of-hammers stupid wingmen it would be the perfect "classic" game)
Freedom: "I won't!"
This would actually give a good performance boost as you could reduce the data on the AGP bus quite a lot ('compressed geometry')
Esp. doesn't DirectX 8 support that kind of stuff? Even if you don't like DirectX (I also prefer OpenGL) it makes the standards...
CU,
Maori
That says more about the limits of applied mathematics than it does about neurons. When your only tool is a hammer, everything looks like a nail. Corollory: when your only tool is the Fourier transform, everything looks like a sinewave.
--
It's a
-- Danny Vermin
The good ol' NV1 from NVidia did this... it wasn't utilized at all, so the future generations of NVidia cards didn't incorperate it.
More beneficial for games possibly, but voxels tend to be used for some rather important stuff like medical imaging. Nurbs, like polygons, only represent the surface and not the interior. If we were talking 2D instead of 3D, your claim would become that accelerated spline drawing for vector graphics would be 'more beneficial' than accelerated raster graphics. I'd disagree - to me voxel rendering is a much more radical step than accelerated Nurbs, and voxels have a host of advantages that Nurbs don't; try comparing polygon-based morphing with voxel-based morphing. Polygon-based morphing has real difficulty with topological changes such as torus / sphere morphs, which voxels handle easily, and few advantages over voxel morphing methods, while voxels seem to have a considerable edge for purposes of medical imaging, etc.
Savant
Ok.. looks like tolldog posted some good links.. :-) )
From reading those links, it also looks like I got the R in NURBS wrong.. it's "rational" not "reticular" (wonder where I got the latter
nope, chevy. (at least, nova and cavalier are chevrolet)
"They think its sexist"
"They think its sexist"
"Well, whats wrong with being sexy?"
It isn't about games for everyone. Games are great but I personally would rather see the acceleration hardware aimed at major CAD vendors (Autodesk, PTC (ProEngineer), SDRC (I*DEAS), Dassault Systemes (CATIA), UG Solutions Inc) rather than games because that would help me more. 3D graphics available today are really pretty slow compared to what I really need. (and yes we have some pretty high end hardware to work on too) Try rendering an entire plant in 3D with product in it and flying around in real time with a reasonable level of detail. (no you don't use a CAD system for this, you use dedicated VR or 3D simultion software like QUEST) The currently availlable hardware still only permits fairly crude cartoonish models. It has been quickly improving though...
Actually what I'd really love to see any of them release their products for linux, but that's another topic... (funny thing is, most of them have unix versions already so it shouldn't be all that hard a port)
From their web page, it renders a 256^3 space in real-time. Okay... Is that only a color sample at each point? Or does each point get a normal, a diffuse, ambient, and specular lighting component - what? Because already, a 256^3 * RGB adds up to 48 Megs - which is not too small. What more are they going to do?
Education is the silver bullet.
switching to another modelling paradigm is not just a case of 'ooh it goes fast!'. The use of polygons is so ingrained in computer graphics today that to move to another primitive would involve a lot of effort.
AFAIK, artist's 3d tools are geared towards polygonal based rendering. It's not a given that artists will find voxels intuitive to model with (although it may be that the raster-vector analogy stands). I'm not an artist so I don't know. But one of the challenges will be providing decent tools.
More significantly, many of the fundemental problems in computer graphics, such as visibility and lighting, have been solved in efficient ways for polygons in particular. I'm not greatly familiar with the current state of affairs in voxel based research, but there's a lot of basic techniques that are used today in polygonal-based rendering aside from drawing filled spans that may not translate directly to a new paradigm.
Perhaps the fact that the accelerator is a hybrid is key, since the different representations can be applied to more suitable constructions. But I think there's a way to go before voxels become mainstream, simply because they don't translate directly to polygons, and hence the class of problems associated with primitive rendering is not already solved.
Gingko
i don't do sigs. oops.
I was just thinking. I read a SIGGRAPH paper about adaptive voxels for real time fly-overs.
The idea was to swap voxels for when the objects get nearer to the camera.
A system could be used like this where voxels are used on all objects that need little detail far away and polygonal objects are swaped in when the object is near.
Just another idea from a sleep deprived soul...
-I just work here... how am I supposed to know?
When games people talk about using voxels (usually for representing landscape) aren't they really often talking about height fields and optimized height field rendering? I've always been a bit fuzzy on this.
And what was up with "voxel-based" characters in westwood's Blade Runner game a few years back?
On the down side, there are some limitations in the current card: no perspective projection (needed for applications like virtual endoscopy) and no way to mix surfaces with volume data (needed for surgical simulation, etc). That's why this news is exciting for us medical folks. As far as the rest of you (gamers, etc), my feeling is that if you build it, they will come. When it gets to the point that voxel data and surface data are handled by the same chip on a $200 video card with 1gig of memory, the game makers will use it.
Actually, I was very surprised the other day when I loaded a using java3d, and saw MS's java3d implementation seems to bind into direct3d! Maybe I'm wrong and the applet was just really well designed, but there was dynamic lighting and the thing looked great, even had perspective correct texture mapping and bilinear filtering. It was the coolest thing I've seen. I'm not an MSBoy, but I had to hand it to whever made that decision.
What we need is for someone to patch opengl into a java applet, for all platforms. Hardware acceleration for 3d web content is way too cool an idea.
- Paradox
Man of the C!!!
Slashdot. It's Not For Common Sense
Don't forgot "Outcast"
Well, voxels are great ways to model landscapes and such, but to make a voxel-based engine with the versatility and freedom of current polygon engines, and one that has similar memory requirements, is a pain. It's a big pain. And it's not even worth it, you don't stand to gain that much. In more limited (non 6dof) situations, voxels can be pretty easy to implement, though.
This is why Commanche used them. Remember Commanche didn't have a full 6dof, and as such it made the voxel engine design easier.
- Paradox
Man of the C!!!
Slashdot. It's Not For Common Sense
The voxel stuff looked a bit blocky when close-up -- but the game ran very well on a P90 32Mb with no 3d hardware!!!
fRoGG
Well, look no further than the latest offering from Sony, the PlayStation2... The GS and EE are capable of providing hardware accelerated NURBS, and are getting put to very good use in new titles...
Specialist Mac support for creative pros, Melbourne
This is not entirely correct. The reconstruction filter of a cheap, low-res monitor is something like a little square (with a little bit of gaussianish convolution). However, the pixel itself is a point sample of some image function.
In any case, show me a monitor that does correct 2D reconstruction of an image from these samples. Can't? That's because it doesn't exist.
Actually, if the original signal is bandlimited below the Nyquist frequency, then reconstruction the image with the sinc filter is guaranteed to produce the correct image. The problem is, most images are not frequency limited, and the sinc filter produces "ringing" on when used to reconstruct those images. Ringing is particulary irksome to the visual system, so even though sinc is the "perfect" reconstruction filter, it's a poor choice when dealing with images. A Gaussian is much preferrable.
Mankind DOES NOT HAVE a model for image processing which is in any way "correct".
I strongly disagree. 2D signal processing is a young but well-grounded field. In terms of reconstructing images from samples, it's provably correct. Theories of visual perception are still a bit sparse, but not so bad as to be called incorrect. Admittedly, we can't explain everything, but we're not totally in the dark about how the visual system works.
Calling it the "path to the Dark Side" is just silly.
I agree that it's a tongue-in-cheek statement, but the fact is that thinking of pixels as little squares keeps people from gainging a good understanding of image reconstruction, filtering, and antialiasing. In this sense, "knowing" that pixels are little squares is worse than not knowing anything about them at all.
I'm not sure who "this fellow" is, but I assume you mean Alvy Ray Smith. In any case, bilinear and trilinear reconstruction functions are not "proper" for all cases, especially in texture mapping. For the highest quality, you need an anisotropic filter. A good discussion of the technical issues can be found in this SIGGRAPH 1999 paper.
Admittedly, bi/tri-linear reconstruction is much better than box-filtering (aka pixel replication). On a very skew polygon with texture, trilinear aliases (either blurs or jaggies) badly because it's an isotropic filter. Anisotropic filters handle this case, but are more expensive.
Consider, for instance, a non-ideal reconstruction filter on an audio channel. This distorts the output. Now you are saying that the input is still a point sample, but the output is distorted. This is totally the wrong way to view things. The output is "correct" - a priori. That's what you hear. There is no way to tell your ears that the actual physical output is somehow "wrong", and instruct your ears to hear the correctly-reconstructed version ... your ears hear what they hear.
In which case, we have to push the interpretation back up the line, and ask the question: if this is what my signal gives me through this reconstruction filter, then what signal would give the same results through perfect reconstruction?
And THAT is the definition of what your samples mean. Therefore, the samples are only point samples if the reconstruction filter is ideal. We like reconstruction filters to be close to ideal, PURELY so we can use the point sample model, because it's much easier than any other sampling model.
This is a somewhat moot point in audio theory, since you can get arbitrarily close to perfect reconstruction; however in image processing the reconstruction filters are nowhere NEAR ideal. Therefore, it is necessary to reinterpret your number sequence as something other than point samples. Unfortunately, this doesn't fit into image processing's usage of 18th-century mathematics, so it's not even ACKNOWLEDGED by teachers of the subject - of course; when you're teaching Newtonian Dynamics you don't waste time explaining that all of it is actually incorrect.
As to the idea that an image can be "bandlimited" - I reject that idea as plain nonsense. It works mathematically, but gives (as you say) visually impaired results in practice. Images just aren't made from frequencies in the same way that sound is. They just aren't.
So, 2D signal processing is a field well-grounded in irrelevant mathematics that doesn't work in pratice. In terms of reconstructing images from samples, it's NOT provably correct, unless you take on board this ridiculous and counter-intuitive idea that images can somehow be "bandlimited". They can't!
I'm not saying that 2D image processing isn't a useful field. It clearly is; using 2D image processing ideas you can do high-quality work. BUT it is totally incorrect to try and force this MODEL from image processing down people's throats, when the MODEL is demonstrably not reality.
Or, as Stroustrup puts it in "Design and Evolution of C++": If the map and the terrain differ, trust the terrain.
--
It's a
-- Danny Vermin
I meant proper as in "better than how Doom scaled up pixels," rather than "proper for best possible image quality."
:-)
You are right. I still think it's an alright tradeoff at this point, at least until anistropic filtering gets implemented in hardware
---
--
Internet Explorer (n): Another bug -- that is, a feature that can't be turned off -- in Windows.
I've heard of pixels and texels, but voxels? Give me a break, 3dlabs! This is the same company that created glint, a long-forgotten proprietary dialect of OpenGL (sort of like GLide)
"Ancillary does not mean you get to rule the world." --U.S. Circuit Judge Harry Edwards, speaking to the FCC's lawyer
ok, back to the original point of this one: WHAT THE HELL IS AN ACCELERATED BEZIER PATCH?!?!?!?!
"Ancillary does not mean you get to rule the world." --U.S. Circuit Judge Harry Edwards, speaking to the FCC's lawyer
Novalogic combined voxels and polygon graphics in Delta Force and Delta Force 2, and the result was impressive, but obviously limited by processing power. Delta Force was smooth in motion, but the detail on the unaccelerated voxels made the landscape look coarse, especially close up. Delta Force 2 tried to be more detailed, but was jerky. It is easy to see, by taking a look at these games, that if the technology is developed, landscapes will look a lot better.
I for one am looking forward to this innovation a lot more than the next paints-3-times-more-polygons board.
q='echo "q=$s$q$s;s=$b$s;b=$b$b;$q"';s=\';b=\\;echo "q=$s$q$s;s=$b$s;b=$b$b;$q"
It tessalates them for you, doof. Those aren't openGL calls you are making, they are calls to the GLU which reduces them to polygons for the machine to render.
This isn't acceleration. When cards can be FED a set of NURBS knots and control points, and do it all itself, then it's accelerated.
Look! My card draws quake models in an accelerated fashion. I call myGGLURenderModel() on a string "Ranger" and it draws the ranger model to screen! No. It's not. This Isn't Acceleration.
Massive DUH! on your part. Read what the damn calls do.
- Paradox
Man of the C!!!
Slashdot. It's Not For Common Sense
Vogon Accelerator.
Such is the infinite Grace of Popeye.
maybe I got the B in B-spline wrong too.
Outcast (http://www.outcast-thegame.com/) was released last year and it's based on a voxel engine. It's the best adventure game I ever player and if you can stand a little pixelation, it's graphics look like what Quake 6 will probably look...
What I wouldn't mind seeing is an emotion-engine enabled graphics card strapped to a high-end PIII or Athlon, but I'm a dreamer.
- I don't care if they globalize against free speech. All my best free thoughts are done in my head.
What is it lately? Are the drug cartels offloading a whole load of cheap crack at the minute?
Strong data typing is for those with weak minds.
Strong data typing is for those with weak minds.
a single cube can take up as little as
72 bytes (48 bytes for all verticies + 24 bytes
for surface descriptions).
a single solid 10 x 10 voxel cube with no
compression would take 200 bytes
a single solid 100 x 100 voxel cube with no
compression would take 20000 bytes
okay.. so the figures arent entirely accurate,
but they demonstrate the point, which is
that while its a good technology for
providing internal details of an object, its
still heavily bloted when your only going to
ever need say 10% of the data stored.
but hey, the more tools the better, the trick
will be in being able to combine the two
seamlessly and quickly...
dms0
You should feel guilty if your just watching - ATR
I think people will only get that joke in the UK :) As it's opel in the rest of europe and GM (I think) in the US.
Is it something that helps you give up smoking quicker ?
> dict voxel
1 definition found
From The Free On-line Dictionary of Computing (15Feb98) [foldoc]:
voxel
<jargon> (By analogy with "{pixel}") Volume element.
The smallest distinguishable box-shaped part of a
three-dimensional space. A particular voxel will be
identified by the x, y and z coordinates of one of its eight
corners, or perhaps its centre. The term is used in three
dimensional modelling.
(10 Mar 1995)
Using your sig line to advertise for friends is lame.
I wonder when the dudes at Bitboys can get their card on the market and how it will compare with the existing cards...
I'm not sure here but i'm fairly suspicious that the original nv1 graphics processor (found on the diamond edge 3d series) rendered splines instead of polygons. I had one about 5 years ago and for the 2 games that were actually written for it it was quite impressive.
From what I recall they went back to polygons because they were easier and you could create a better impression just using a lot of poly's.
Isn't the Chevy Nova a remarked Toyota Tercel? I wonder if they have trouble marketing it in South America and other Spanish-speaking places where "no va" == "no go"
You know, we'll never hit a "don't-care-faster" point with 3d cards. There is no "good enough" speed because you ALWAYS want more polygons to work with. Look at the huge lengths people go to to approximate real per-pixel-lighting (as opposed to polygonal vertex based lighting that most people use today) and extreme surface detail in real time. Bump mapping, elevation maps, texture maps. All of these are there to simulate detail that isn't there. We have a very long way to go.
However, lets say someone makes a card that just pushes a huge amount of polys.. so much your computer can't drive the card fast enough. Whew. Great. But now there is the whole world of realtime raytracing to work with! Someday, we want to move out of fake lighting models and drawing polygons to realtime recursive raytracing, and dare I dream it, radiosity to solve the global illumination problem! Imagine.. assuming your textures are colors are photorealistc, your image will be too. Taaaddaaa.
So the reason this stuff is so important is because it's for legwork. Besides, lots of companies are trying to make massive multiuser shared environments. In 3d. Good 3d. Like what high end Nvidia and ATI cards (GeForce2, Quatro2 and Raedon) can support. That, my friend, is something right of out Snow Crash, and quite frankly I think it would kick ass. I'm looking forward to seeing this hardware become faster and faster.
'sides, the simulation people will scream "How can we get any work done if we can't SEE!". All this 3d hardware isn't applied to just games. I'm working at a company that is spending tons of money on SGI's and x86 machines with excellent video cards because they do VERY complex engineering modeling and they want to be able to see it! GeForce2's and Quatro2's being put to a very serious use. So don't laugh off this industry because you aren't a gamer. This is the future of interface design here. Try and keep up with it.
- Paradox
Man of the C!!!
Slashdot. It's Not For Common Sense
They're actually "surfaces of elevation". But Novalogic, starting with their ground breaking Comanche game, abused the terminology, and called their clever rendering method for surfaces of elevation "Voxel Space[tm]". (They tried to patent it too.) The terminology stuck.
Whatever. In 5 years surfaces of elevation will rule the 3D game world. Call them what you want to.
--
When all you have is a hammer, every problem starts to look like a thumb.
It's just a very clever troll, the accelerator is on the right everywhere.
---
I am the dot in slashdot.org
It's been said before, quite often, that /. isn't just for group X. You don't game, fine, that's your choice, live long and prosper, etc. etc. But many of us on /., myself included, enjoy a good fragfest every so often, or like a detailed flight sim, etc. etc. So stuff like this is interesting to us. Also, having seen 3D surgical applications in action here at my University, a card with the capabilities they describe could be very useful to the medical and scientific communities. So, really, its gaming, rendering, training, experimenting, simulating, teaching, etc. Not for Joe Average maybe, but far from pointless.
-={(Astynax)}=-
-={(Astynax)}=-
"Darkness beyond Twilight"
who's gonna write the first mozilla based application that takes advantage of this :-)
(now someone is gonna read this and write an article saying that mozilla is spending too much time on voxels and not enough on writing a web browser!)
As I'm not a graphics programmer the significance of this has went over my head but I'm sure all these gamers out there will be able to benefit from this. The more accelerated hardware for doing things like this has to be a good idea as software rendering is very CPU intensive.
Hmmm... takes me back to my Senior year in Surfaces and Modeling.
I think that accelerated Nurbs would be more benificial. At least nurbs are the choice of Maya... I can't remember what the other packages like.
But... accelerated Bezier patches is a step towards faster nurbs.
-I just work here... how am I supposed to know?
3-D-accelerators do not accelerate high-quality rendering, where ray-tracing and radisiosity and such are used.
They're great for when you're modelling, so you can get a quick preview and get a decent idea of how highlights and textures are going to look, but, for the final render, they're not very useful.
-rozzin.
Really pisses me off when people forget that the ACCLERATOR is on the RIGHT.
You know, when I read that article, it got me started wondering if I would be able to use the xbox's particle system to emulate voxels.
-- Superlame http://catpro.dragonfire.net/joshua/
With a polygon (or other surface type) based model you still get a smooth image.
That's actually not quite right; polygon meshes begin to look very faceted if your model isn't composed of small-enough polygons, or if you get close enough. One polygon is smooth, but a whole bunch of them, put together at the edges, is not smooth. The problem with polygon meshes is largely `solved' by doing surface-normal-perturbations and such, so that, for the mesh surfaces that are more perpendicular to the viewer's line of sight, everything looks smooth. This doesn't help the edges, though.
Splines guarantee smooth surfaces of any form at any resolution, but the equations become increasingly complex as the numbers of of control points increase (the orders of the functions go up). To get around this, you can break a surface up into a number of patches, and keep each patch relatively simple (16 points, and a quadratic function, for example).
It can be tough to work with things like Beziers, though, because increasing complexity in one area of the surface can lead to increased complexity in some other, `completely unrealted', area. Of course, Beziers are also more expensive to calculate than triangles....
Subdivision surfaces are nice--you basically create a triangle mesh and then smooth out all of the corners (really smooth them, not just play with the way that light reflects off of them). Subdivision surfaces give you the ease of use of polygon meshes, and the high quality of spline patches.
Hm. I guess that I'd like to see subdivision accelerators:)
-rozzin.