ATi Releases More Xenos Info On Website

Hasn't it been stated enough times by now that pretty much the only advantage raytracing has over conventional rendering on today's GPUs is deep levels of reflections, and what sort of game would you build around such a feature? Throw in a couple mirror funhouses into every level?

Raytracing is one of those checkbox features that were cool once upon a time, but has lost all relevance since, except the internet laypeople doesn't yet know that.

 

Raytracing is very important to practically all ('real' or CG industry standard) implementations of global illumination, ambient occlusion, and subsurface scattering.

 

We're heavily displacing EVERYTHING here
It works well enough in most cases, because the displacement is always relative to the surface, along its normal - so when you bend a limb or something, the displacement 'moves' with the skin.
(There are methods to displace along other directions and not just the normal, but it's hard to get proper data for that... so most people stick to standard displacement.)

You have to be careful not to go too far with it though, like, displace a horn or such a big thing. First it'll kill the accuracy of your map, because the maximum displaced distance defines the amount of elevation between two intensity levels (I don't expect games to use floating point maps for this in the near future...) and second, larger features can get distorted when the underlying surface is deformed by a skeleton.

Shameless plug... here are two characters from our recent work:

http://hardwired.hu/img/wg/2/623/Warhammer_Mark_of_Chaos_52.jpg
You can see here the original geometry in a black wireframe, overlayed on top of the displaced surface (this is an ambient occlusion pass so no textures or shading here).

http://hardwired.hu/img/wg/2/623/Warhammer_Mark_of_Chaos_51.jpg
Here you can see how much silhouette detail we can get with displacement; but also that all the larger features like horns are modeled in, and that the polygons are laid out to support animation (and they're also quite uniform to make the Zbrush painters' job easier).

http://hardwired.hu/img/wg/2/623/Warhammer_Mark_of_Chaos_47.jpg
http://hardwired.hu/img/wg/2/623/Warhammer_Mark_of_Chaos_48.jpg


Also note that we're using Pixar's Renderman for these, which tesselates everything adaptively to micropolygons smaller than a final pixel. IIRC we've been using a shading rate of 0.5 which means ~4 micropolygons per pixel. The tesselator in Xenos probably won't be able to create such a dense mesh for everything in the scene... so like, you could do up to 4 tires, but go with lowpoly characters and enviroments
Seriously, I expect that developers will probably have to budget their resources properly and use the tesselation/displacement for some key elements in a scene. Like the T-rex in King Kong? Although it didn't look displaced to me, 'only' tesselated with smooth curved silhouettes.



Another interesting info is that that creature in the slides has been made by Bay Raitt, if I'm right here; he has modeled the face and most of the expressions for Gollum in the LOTR movies and is working at/with Valve for more than a year by now...


PS: you can watch the whole animation here:
www.digicpictures.com

 

Very interesting, thanks!

 

Laa-Yosh,

Very impressive work! Although that last image creeped me out. It reminded me of something I watched on the Discovery channel.

 

Laa-Yosh,

are you making games for the 360? sorry for the noob question!

 

Thank for the info. From your perspective where do you think displacement would be most useful? Character faces for closeups, details on vehicles, or scenery prehaps? Which do you think would gain the most advatange from this?

I'm guessing that as you can model the details, the main advantage to displacement is the ability to write to the displacement map. That is, everything you can displace in game, you can displace in the model used in game. Though it would have a BW saving (or would it?) so if a simple model+displacement was smaller than larger complex model, it'd be a better choice.

Just trying to understand what displacement brings to the table.

 

about realtime displacement map :

http://divideconcept.net/index.php?page=d2k4/index.php
this guy does the best per pixel realtime displacement i've seen yet.
It works on arbitrary model .It's GPU subpixel (micropolygon) displacement mapping .
He generates it's own 16 bit format to displace.
Unfortunatly, he did'nt work on the base of real dispmaps ,but just converted the diffusemap.
Try the videos sample bottom of the page.

 

No, we're doing cinematics for games at the moment, this is a trailer for the upcoming Warhammer fantasy RTS.

 

This if for Namco right?

 

Yeah, it was first shown at E3 this year.

 

Wow, this looks very cool. How can he do it, software tesselation or what? I thought there's not enough support for this in current hardware...

 

Cool, namco asked us to pitch them something using the same license.

 

It's all hardware.
he keeps some secrets ,but basically ,he don't draw new polygons, it's all pixels ,but mathematicaly in some way he works on micropolygons and heavy raytracing.He came where i work.So i've seen it realtime and live It's really impressive.

the cool thing is that he can linear Z-LOD the effect on the same geometry.
http://divideconcept.net/d2k4/render/nonuni_disp.jpg