Notch defends his previous statement calling Euclideon a scam • Hacker News Board

Re: Notch defends his previous statement calling Euclideon a scam

#51

Post by martinkallstrom » Thu, Aug 04, 2011, 1:24 AM UTC

mey wrote: post #44

martinkallstrom wrote: post #29

I have the highest respect for you Notch and personally know people on your team (Carl), but you're out on a limb here. Sparse Voxel Octrees are frickin awesome and Euclideon aren't wrong for saying so. There are drawbacks with them, but they are one by one being picked off by research. Animation is one example, dynamic lighting and shadows can be done in screen space. There is a real chance that soon enough voxels a…

To me the video is a scam. It gained massive attention attempting to compare itself to contemporary game engines without clearly representing any of it's limitations that prevent it from being used for anything. To me is screams as a way to get enough attention to continue funding of the project with no short term result (at least in the video game field that they are contrasting themselves with.) They display two sc…

I respect your opinion. If the points you make are true, I would however phrase that as a lack of product/market fit, not a scam.

Each of us put different meanings into words. I want to reserve the word scam for when there is provably no intent to create real value. To me there is no conclusive evidence of malicious intent here, only a heap of speculation.

Re: Notch defends his previous statement calling Euclideon a scam

#52

Post by ChuckMcM » Thu, Aug 04, 2011, 2:41 AM UTC

dpark wrote: post #46

ChuckMcM wrote: post #45

Voxels have a bad reputation in the graphics community. Back when I was absorbed in this and writing my 3D 'engine' I got to see this debate in its infancy. There is an intermediate form, non-uniform rational b-splines or NURBs, which the first nVidia card rendered directly. That made it possible for the NV1 graphics card to render a perfect sphere with just 6 NURBs vs triangle based engines which required dozens if…

> a voxel 'rock' or other solid doesn't need to represent the 'inside' with voxels This seems to contradict Notch's (and Wikipedia's) description of a voxel. They indicate that a 3D space described by voxels has a voxel for each unit in space. The is analogous to having 1 pixel per unit of display space. If this is correct, then a rock would indeed have the inside filled with voxels. I might be misunderstanding, thou…

I don't think you are misunderstanding so much as conflating two things, the co-ordinate space / construction of the world and construction of objects within that world.

It's correct to say that every 'point' in a voxel based world can be represented by a voxel in that point. It's incorrect to say that every point in a world has voxel data associated with it. Perhaps this is the place where Euclideon and Notch diverge as well.

Using a quantized world representation view (where co-ordinates in the world are quantized to voxel boundaries) then as a voxel moves through the world space it moves from point to point in that space. So a 'cloud' of voxels has an origin and an orientation in worldspace, that allows the translation of a local voxel space (the object) into world voxel space. Since you can't do sub-voxel positioning it behooves you to have an oversampling rate between voxel space and display pixels as well.

A 'feature' here is that it also allows for fine grain collision detection (harder to do in polygon space) but again its pretty expensive computationally. (boundary surface intersection of the local voxel space with the world voxel space).

Re: Notch defends his previous statement calling Euclideon a scam

#53

Post by mrcharles » Thu, Aug 04, 2011, 1:12 PM UTC

bane wrote: post #47

mrcharles wrote: post #35

Earlier quoted context omitted.

But that also makes the incorrect assumption that each of those voxels must be populated -- which isn't necessarily the case. In fact, more will be unpopulated than populated, I would expect.

Good point. Still, I wonder what the data requirements of even a sparse voxel world of this resolution would require?

Generally, I expect it would be equivalent to the surface area of all objects.

Re: Notch defends his previous statement calling Euclideon a scam

#54

Post by dpark » Thu, Aug 04, 2011, 3:32 PM UTC

ChuckMcM wrote: post #52

dpark wrote: post #46

Earlier quoted context omitted.

> a voxel 'rock' or other solid doesn't need to represent the 'inside' with voxels This seems to contradict Notch's (and Wikipedia's) description of a voxel. They indicate that a 3D space described by voxels has a voxel for each unit in space. The is analogous to having 1 pixel per unit of display space. If this is correct, then a rock would indeed have the inside filled with voxels. I might be misunderstanding, thou…

I don't think you are misunderstanding so much as conflating two things, the co-ordinate space / construction of the world and construction of objects within that world. It's correct to say that every 'point' in a voxel based world can be represented by a voxel in that point. It's incorrect to say that every point in a world has voxel data associated with it. Perhaps this is the place where Euclideon and Notch diverg…

What I'm not understanding is the object space. If a voxel's coordinates are implied based on its position, then there would be voxel data for every "point" in the object space. Unless we use a sparse representation of some sort, in which case it seems that we're basically using point clouds.

Re: Notch defends his previous statement calling Euclideon a scam

#55

Post by dpark » Thu, Aug 04, 2011, 3:38 PM UTC

zethraeus wrote: post #49

dpark wrote: post #46

Earlier quoted context omitted.

> a voxel 'rock' or other solid doesn't need to represent the 'inside' with voxels This seems to contradict Notch's (and Wikipedia's) description of a voxel. They indicate that a 3D space described by voxels has a voxel for each unit in space. The is analogous to having 1 pixel per unit of display space. If this is correct, then a rock would indeed have the inside filled with voxels. I might be misunderstanding, thou…

as I understand it, the disparity in explanations can be attributed to that we're talking about using voxels in a data structure known as a sparse octree, that would in itself be used to optimize the system by, among other things, allowing only the surface information to be stored. edit: http://en.wikipedia.org/wiki/Voxel http://en.wikipedia.org/wiki/Sparse_voxel_octree

Thanks. I'm a little confused how this differs from a point cloud, though. Or perhaps it'd be more correctly called a "cube cloud"?