Soft shadows

[EsH]

Hi

It's looking more likely that the next Doom3 engine will give us the soft shadows we're looking for:

http://www.ce.chalmers.se/staff/tomasm/soft/

Interestingly, the next Unreal engine might have the upperhand in this, as an earlier screenshot seemed to imply this new engine was using soft shadows. Does anyone know anything about this?

I guess this is another example of how fast things are being outdated. When Doom3 was first shown, it was state of the art as far as most of us were aware. Now, with the game not even out yet, yet we have demos of high-dynamic range post-proccessing, soft shadows, subsurface scattering using spherical harmonics... It's really amazing, but frightening because Id has put so much hard work into creating an impressive visual experience, but thanks to the internet, we have access to all these one-upper's.

For larger, extensive games, it might be next to impossible to keep technologically ahead of smaller games. This might actually give "garage" developers an advantage over the larger publishers-- they'll be able to offer the latest technology, and get the game out there, while the larger more elaborate games will have these long, somewhat stagnating art production cycles. But of course, graphics technology is just one aspect of a game, and isn't the foundation for good gameplay.

[Linguica]

AFAIK Carmack always planned for Doom 3 tech to do straight stencil shadows and the next-gen engine after that to do soft shadowing.

[BNA!]

Thanks for the link!

Never mistake an isolated tech demo with a full game engine which as n-more tasks to process before swapping the back to the front buffer.

These demos run with 50fps for complex scenes and 150fps for simple scenes. If they use multiple objects casting shadows onto each other frames will drop below 1fps.

Since you can consider each scene in a game as complex, performance for the lighting and shadowing part alone would require a relative long rendering time.

I doubt that we'll see robust soft shadows with a unified lighting model in the next few years, but I'm clearly not an expert.

Regarding the next Unreal engine:
The movie I saw looked like the engine looks up a texture to render the shadow outlines with a gradient which makes it look soft.
Real soft shadows in a meaning where they have a real time computed fall off are far away from us (IMHO). Still the shadows in Unreal could be "just" projected shadow maps which get rendered to texture and then projected.

So far there's no game engine yet which comes close to Doom³.

There are engines which offer a similar feature here and there, but as a generalized solution I'd like to think that the Doom³ engine stands on top right now and for some time to come.

[EsH]

Hi BNA.

Yeah, I know there's a heap more to an engine than the shadow rendering code :) I didn't mean to imply that a small team could compete with the Doom3 engine on a code-base basis, only that it's possible to create smaller, more modest engines that none the less meet or excede the general rendering quality of comercial engines in certain ways. For example, the Tenebrae engine http://tenebrae.sourceforge.net/index.php?page=screenshots.txt is not as robust as Doom3's-- the complex culling algorithms, the surface tracking-- it just isn't there. But it still is capable of showing the same sort of output as Doom3 (especially if you look at the newer maps especially designed for the engine). I guess the point of what I'm trying to say is that a smaller developer could "whip out" a smaller game, and ride the technology crest of another, more popular game such as Doom3 before that more popular game even comes out. Yeah, I guess this is a blatently obvious and pointless thought.

The shadows in the new Unreal engine were cast from and onto complex, not-nessesarily-convex objects. AFAIK, projected shadows require simply bounded convex type meshes, and don't self shadow. Shadow depth mapping only really works with the stencil buffer (and so doesn't do soft shadows). So, Unreal is either using a method similar to the one described in the paper mentioned in the first post, or (as it was a static scene) they are using some sort of spherical function to do self shadowing. Or something else ;) What I saw didn't look like primitive shadow mapping or anything.

[BNA!]

Thanks for your reply EsH!
I fully agree with your post above.

Regarding the next Unreal engine:
I saw a couple of short tech movies from various gfx board launch events. It looks good, but it looks odd - can't describe it any better.