Speculation.. Z3 HD Meshes

[testure]

So I was sitting around today looking at all of the gorgeous Z3 beta images and the former CS major in me began to wonder how this HD-mesh technology actually works. I’m sure pixolator’s not going to chime in here and give away any trade secrets, but I enjoy speculating on things like this. Z3 beta testers are claiming that they’re using 10 times as many polygons on the same machines that they were formerly using Z2, so there’s obviously some technical magic happening behind the scenes.

I came to the conclusion that the Z3 rendering core must use some sort of normal/bump trick to give the impression that you’re working with more polygons than you actually are. For example, when sculpting in the digital realm, there are two main axioms to follow in regards to handling geometry: #1) if the change in your mesh alters the silhouette, displace it (so, use real geometry). #2) For medium to high frequency details that do not change the figure’s silhouette, use Normal and/or Bump maps.

My guess is that the Z3 rendering core intelligently decides whether or not your mesh has changed enough to generate the geometry for an area, and decides whether or not to use smoke and mirrors (normal/bumps), or the real deal (geometry). I suspect that this is all behind the scenes, as sculptors no doubt want the geometry they think they are sculpting, so at export time Z3 probably creates the geometry based on the same logic it uses to determine what is real, and what is faked.

Just my guess, it seems the only logical explaination due to physical restrictions of hardware that’s on the market today… any thoughts?

[MrWyatt]

Not that I know anything, but as I understand it HD streaming means that the whole mesh is written to harddisc drive (hence the name “HD”) and also read directly from the harddrive. Mudbox does the same and is also capable of multiple millions of polygons, but the data is huge and you allways need a few gigs free to work really well with large amounts of polys. it creates temporary files that can easily go over a few gigs. and the files you save also are enormous. I guess ZB3 has a similar approach. So I guess there is no trick which involves making the user believe things that are not there.

[lemonnado]

I don’t think that public re-engineering will be popular here
And no, ZB does not store the entire mesh as ‘mesh data’ like Mudbox.
Lemo

[testure]

HD could also mean ‘high density’ :D. I use mudbox in addition to ZBrush, and I can tell you that on my above-average PC I can’t get over about 4 million polygons, and the 3-4mil poly range is tenuous at best. However there are beta testers claiming 6-mil polys with an average PC in real time. There’s definately some trickary going on

And yeah, I didn’t expect a huge response to this thread… just my own musings that a like-minded person might stumble upon one day.

[aurick]

Speculation is something that we really do try to discourage. There are several reasons for this, not the least of which is that your speculations can be taken out of context and posted on other websites. This then creates false expectations among people who aren’t familiar with the original context.

I know that with all the excitement about Z3 it’s pretty much impossible not to speculate. But please keep it to yourselves and wait for the release to see whether you were right or not.

Thanks.

[testure]

Eh… well that’s the thing. Whether I speculate about it now or after it’s released it doesn’t matter. It’s not like you guys are going to release a whitepaper with the inner workings of Z3, so it’s irrelevant

[polsons]

Speculation is something that we really do try to discourage. There are several reasons for this, not the least of which is that your speculations can be taken out of context and posted on other websites. This then creates false expectations among people who aren’t familiar with the original context.

I know that with all the excitement about Z3 it’s pretty much impossible not to speculate. But please keep it to yourselves and wait for the release to see whether you were right or not.

Thanks.

If you create something new and exciting people are always going to speculate how it is done, but it is nothing more than well intentioned, ill-informed speculation until someone jumps in and says you shouldn’t be discussing this because…

I think you’ve fallen for the age old trick long used by the Mac community against Apple. Throw a few ideas out into cyberspace, wait to see which one incurs the wrath of Apple’s legal gestapo and bingo! you’ve hit the jackpot. Works against Apple every single time. And because of that I think you can now expect to see the first post in this thread quoted on every website, whether it is true or not.

All I’ll add is that as long as it works, who really cares how it’s done.

[Crusoe_the_Painter]

Since it’s been stated many times that Zbrush does not use the 3d card much ( what card could rotate a 6 million+ model in real time? ), there are all sorts of cute tricks zbrush could be using under the hood. As a programmer, I’d love to read a white paper about it. The fact it’s disk and processor bound in terms of polygon count is awesome.

I have a few ideas of my own though…