HalfLife2 like facial expressions and physics

#1 There has been talk of implementing the Open Dynamics Engine into TGE opende.sourceforge.net/ But i dont know if anyone has finished. The other stuff you talk about, why bother building something in hl2, and then have to rebuild it in some other engine (can you afford to licence that engine... heh) afterwards? Why not just spend a little time learning TGE and create whatever you want and sell it instead of making a mod that will be overlooked because its not "Counter Strike 2" or whatever.

Basically, what you are asking is probably possible in TGE (the dynamics are at least possible, just needs some elbow grease to get it working), Cel Shading has been done, The rest depends on your and your team's skill.

For me, this sucks because im a slacker and the only person working on my game. Heh.

Of course, thats just my $0.02, and the hl2 sdk might be like really fricken ninja sweet.

Ryan Ackley
JKAP Games

#2 @Trane: competing with the top notch technology as an Indie isn't an option. Unless you are a very skilled programmer who has already published a couple of titles and have written some papers on 3d theory.

#3 You said the Cel Shading's been done? Give me a link... I'd like to see how well. And as for the dynamic part... I'd be happy to get it done, but... would need some help... not even sure how they got it done.

I would rather build it in Torque... especially if those features can be built in to it.

#4 @Trane: let me say that you will most likely not be able to implement a physics system like halflife's. Definetly not, cel shading, sure, it's an easy extra render pass, though since torque's rendering system is distributed all over you would have to add the extra render pass to every renderable object. But hl2 like physics? Forget it.

#5 Facial animation definitely possible. The animation system already in the TGE can support bone driven facial animation and expression that can be blended on top of the movement animations. I have done tests with this so I know the art end of it works. The coding end of the system to drive the face would need to be done, but the art is certainly not going to be a big problem.

#6 @Joe: Or you could always have fake mouth movings or random ones, that play while the char is talking :)

#7 ...which is what lots of RPGs do, and it looks like crap, but hey, it works. I like halflife2's approach a lot better.

HL2 type physics aren't impossible with Torque, but they'd take some work, as you said. I don't know if anyone's done a lot of work with Torque's physics, seeing what's possible with what's there. Quite a bit, I think...

#8 Doesn't Half-life 2 use Havok2 for it's physics? I think that's "only" ~$50,000. So if you license that you can have the exact same physics as half life :)

However ODE is a great option for the rest of us. And to be fair it doesn't seem that far behind (and in some areas better). ODE has an excellent mail list / archive, community, and wrappers for virtually every language. It's handedness and major columns are the same as OpenGL. Which makes it fairly awkward to use in Direct3D, but suits Torque fine.

Tokamak is another free alternative and allows a good few things even havok can't do. However it looks like they're angling to sell you version 2.

A full physics engine would take far too long to be viable. Especially when considering these excellent alternatives. The only exception to that is the VS/PS based physics systems, but you can't do the really impressive stuff until version 3.0 of either (that would be the next gen of hardware).

The facial animation that Half-life 2 uses is something very different to the normal approaches. The closest I've ever seen was at a presentation by nVidia (Vertex clusters groups or something like that). I've never found the presentation online though, so I only have my rather poor notes on it. There are licensable face creation / animation engines though, but I don't know of any free ones. However as Joe pointed out, there are perfectly valid alternative approaches.

There is some GPL stuff that analyses wave file (and some Intel SDK's) and produces text / phonemes. These can be used to drive morph targets that can produce some very high-grade animation, something that could potentially be done quite quickly,

#9 For free facial animation tools, check expression.sourceforge.net/...

#10 So what's the deal with opensource? Does that mean I can use the code as a foundation, develop upon it, and integrate with my code for use in a commercial product? As long as I give copyright recognition to the respective owners?

And is the TGE built with C++? Because I keep getting different answers on this. If I use TGE, will I want to use open code written in C++? Will it be compatible?

I am poised to take a programming course in C++, so I just want to know what I'm getting myself into, and if I should get my hopes up, when I see things like expression.sourceforge, and the ODE.

#11

Quote:So what's the deal with opensource? Does that mean I can use the code as a foundation, develop upon it, and integrate with my code for use in a commercial product? As long as I give copyright recognition to the respective owners?

It depends on the specific license you're talking about. GPL software means you need to open source your program as well. LGPL means you need to open source any changes to the library you use, as well as allow the user to update the library independently of your application.

Torque is written in C++.

#12 Mark is correct about the licenses, there's lots more but those two are the most important ones and widely used.
Now you give me one more point to say, that you should forget about hl2 like physics, you don't know C++. It will take you years to put up with a skill level to be able to hack on Torque to integrate those physics systems, It isn't like click, drag, copy files, done, we now have ODE. You will have to modify all the Torque physics engine to use calls to ODE specifics and make it react using ODE's responses. Not easy, not at all. It can be done as it was said before, but in the 2~3 years Torque has been out in GG no one has done it, and we have some very talented programmers in the community.

#13 Xavier, not exactly true, as Jeff said the other day :
-Tube Twist uses ODE for the physics in a TGE game
-Another unnamed, commercial TGE project uses it too :)
To paraphrase Jeff (can't remember which thread he mentioned this in), neither team has plans to release their work to the community, so far.
Apparently, not that hard :)

#14 Didn't bother to read the other posts so I dont know if this has been said already but just about everything that looks good about HL2 comes in part from the Havok physics engine. Everything in the game to barrels to your body has a wieght mass and displacement force blah blah. The facial expressions I read somewhere were due to place wieght and mass in some specific places where muscles would move and a insanely complex bone structure then they just animated certain frames for animations so this means that all the chars in game have the same set of expressions tied to this complex bone structure which means in short that I don't see why you couldn't do this in torque as long as you are using 3dsmax. Seems to be a few major issues with the exporter for milkshape.

#15 @Nicolas: How is that an answer to what I said? You are saying than because it's done it's easy to do so?

#16 I only answered to you saying "No one has done it"

#17 Oh, well, I meant done it and released it :)
I knew about the tubes game, and even Ben Garney did some work...

And by now.. I'm doing ODE work too ;)
Stay tuned.hehe

#18 So is anyone going to release a little bit of work using ODE?
Or maybe even a little basic resource meant as an example?
Something like an example of how to make a simple test using a few crates or barrels or a rope would be cool, just something to show how it could be done and show a starting point!

*Brain goes into overdrive*

#19 If you need an example download the ODE source code and look at their examples.

#20 Far down the road, when I've got my ragdoll stuff done, I want to try to work with Tim or another GG employee to get some basic ODE support into HEAD.

But that's six months or more down the pipe, so don't hold your breath. :)