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[Melly]

What's the difference anyway?

Is there a difference?

[joshg]

Voxels are pixels with volume.

Trixels are pixels with ... tricks?

[Massena]

Voxels certainly sound sexier for one, but I recall seeing an interview with the coder from fez explaining the difference, I'll try to dig it up.

[Terry]

I assumed that the difference was that while a voxel is a 3D pixel, a "trixel" is a 3D tile. But I don't know for sure - it's Fish's term.

[Zaphos]

Renaud's answer was here: http://www.zaknafein.hjcrusaders.com/?p=29

In short, trixels are a special case of voxels which (1) are tiled (kind of like IIRC outcast's heightmap voxels, except now the tiles are cubes not squares), and (2) are rendered as cubes (like voxelap), with a custom surface extraction algorithm (unlike voxelap?).
Visually they are not really different from other systems that render voxels as cubes.

I guess you could also use the term to describe any voxel rendering which is intentionally attempting to extend a pixel aesthetic to 3D, since that seems like the most important aspect.

I assumed that the difference was that while a voxel is a 3D pixel, a "trixel" is a 3D tile. But I don't know for sure - it's Fish's term.

Trixel would be a 3d trile element, like a pixel is a picture element, where the trile is a 3d tile.  So the trixel itself is the 3d pixel.

edit: Oh, and he gets color from a cube map, which is pretty neat.  Not sure it is fundamental to the definition of 'trixel' though.

[Lazer]

I think this can all be summarized to "a healthy dose of awesome separates them."

[fish]

its an aesthetic thing.
trixels are meant to be an extension of pixel art and its aesthetics into the third dimension.

whereas voxels always look like shit.

theyre not a crazy new technological breakthrough or anything.
its just how we handle things, and how we named said things.

[Lukas]

voxels always look like shit.

You -fail- (at saying right things). Sorry. 


Edit:
Ah, I'll add evidence:

[fish]

i stand by my original statement.
that looks like ass.

[deadeye]

voxels always look like shit.

While this is true, I don't see why it has to be.  Seems to me that a voxel engine could conceivably be made with just as much detail as your fanciest polygon-pushing engines.

Plus it would be easier to do volumetric things like veins, bone, and muscle tissue and such.  For instance, with polygons when you chop someone's arm off with a sword you have to make two models of an arm, and you're limited to pre-defined places where the arm separates from the body.  For instance, the arm is only designed to come off at the shoulder, even if you chop into the elbow.

With voxels you could have bone and muscle as volumetric information within the model.  Slice at the forearm or elbow, it separates at either place.  Slice along the length of the arm, get a cross section that renders properly because of the volumetric info.

At least, in theory.

[threesided]

To jump in quickly, I would say the thing making those "voxels" look like shit would come down to colour choice, NOT the technical side of things. Anything can look good with the right artistic prowess behind it.



Perhaps I shall conver to voxel artist, see how that goes. Or maybe trixels! Then we'll see how much suck is in them.

[moi]

Well it's difficult to compare as we don't have any finished game using trixels at the moment.(this is the polite version of my post)

[fish]

oh also one thing about trixels is that they are totally polygon-based.
and magic-based.

[Mitchard]

While this is true, I don't see why it has to be.  Seems to me that a voxel engine could conceivably be made with just as much detail as your fanciest polygon-pushing engines.
At least, in theory.

No, that just seems like a nightmare. Doubling the detail of a voxel model would increase the amount of voxels needed 8 fold. Seeing as this voxelstein dealy can make my dual core hang for a few seconds when a large explosion goes off, it really doesn't seem that viable.

[Zaphos]

Hmm, "trixels are voxels,"¹ so if voxels always look like shit then trixels always look like shit 
So, don't be so down on yourself, Mr. Fish!  I think your game looks fancy

While this is true, I don't see why it has to be.  Seems to me that a voxel engine could conceivably be made with just as much detail as your fanciest polygon-pushing engines.

Modulo the hardware to run it on, this is true.
If you accept engines that use voxels as an underlying representation, but output polygons or other nicer surfaces to render, then I think actually a lot of really pretty water and gas sim stuff is done with a 'voxel engine'.  Especially if voxels are allowed to be represented by octrees, not just naive 3D arrays.

Plus it would be easier to do volumetric things like veins, bone, and muscle tissue and such.  For instance, with polygons when you chop someone's arm off with a sword you have to make two models of an arm, and you're limited to pre-defined places where the arm separates from the body.  For instance, the arm is only designed to come off at the shoulder, even if you chop into the elbow.

With voxels you could have bone and muscle as volumetric information within the model.  Slice at the forearm or elbow, it separates at either place.  Slice along the length of the arm, get a cross section that renders properly because of the volumetric info.

At least, in theory.

You can do this stuff with methods other than voxels.  For example, see http://www-ui.is.s.u-tokyo.ac.jp/%7Ekenshi/LappedSolidTextures/index.html
(that's a new siggraph paper, but there's older similar stuff I think)
Tetrahedral meshes are used for finite element sims a lot, I think.


¹ This is a quote from Renaud.

[Xion]

Can you mix voxels and polygons?

[Zaphos]

Can you mix voxels and polygons?

Yep.

Outcast was a hybrid voxel / polygon engine, although apparently by voxel they really meant height field.

Also, voxel data is very often rendered via polygons ('voxel' refers more to a data structure than a rendering algorithm), which makes it quite easy to mix in polygons that did not originate from voxel data.

[deadeye]

No, that just seems like a nightmare. Doubling the detail of a voxel model would increase the amount of voxels needed 8 fold. Seeing as this voxelstein dealy can make my dual core hang for a few seconds when a large explosion goes off, it really doesn't seem that viable.

Considering there was a voxel engine game called Outcast with much higher resolution images than the Voxelstein thing that was made almost ten years ago, and didn't even need a 3D card to run, I'd say that's a problem with the Voxelstein engine specifically and not voxels in general.



Edit:
Urp, beaten.  Sorta.  I should really read the rest of the thread before replying.

[Zaphos]

Like I said, Outcast just does heightmaps; it's not the same thing as voxelstein.  Doesn't enable the same neat tricks.

Curiously, I think the technology behind the Cube engine is pretty similar to the tricks that made voxels fast in Outcast.

It definitely seems likely that for realism you'd want a voxel rendering method that does interpolation; uniforms stacks of axis-aligned cubes tend to make a pretty ineffective shape approximation.

[december]

Seems to me that a voxel engine could conceivably be made with just as much detail as your fanciest polygon-pushing engines.

Go look at mode 7 graphics.  Not that great, even if it seemed cool at the time.  Think about how much the images in mode 7 distorted when they rotated.  Because it was all pixels, and those lose detail when you rotate.  Polygons are vecotrs even if they are textured with bitmaps.  Rotating is what they do.  Voxels offer the same mode 7 bullshit that didn't really look that great back in the day and does that in 3d.

Also, how would you anti-alias something that represents a volume of a physical object rather than just an image?