Physics Engines

I was somewhat taken aback last night when Iain told me that physics chips for games were no good.
He expanded on this by saying that because the data flows over the PCI bus, it slows everything down.

Now, wouldn’t they be PCI-express cards? Hm.

Today I ran across a Slashdot story titled
Comparing PC Game Physics,
which details how the companies behind the two big physics engines are depating each other’s merits on public forums.

Apparently it started when Havok, the company behind Half-Life 2’s physics engine (I guess it’s a 3rd party library that the Half-Life guys licensed?)
commented on
Ageia’s PhysX card being used in Ghost Recon Advanced Warfighter, which also a Havok game.

Ageia has now
shot back a response.

Interesting goings-on..



6 Responses to “Physics Engines”

  1. iainb Says:

    Ageia has released a new driver (2.4.3) that fixes the issue first noted by AnandTech. The Tech Report is still waiting for their review sample so I am holding my breath until then.

  2. MikeC Says:

    What I got from that response was that the people at Havok lied about the Ageia system in some instances. Or maybe they were just wrong? What really disturbed me though, was that Ageia didn’t adress what Havok said about the extra objects put in by Ageia’s PPU and how they didn’t affect game play and weren’t solid, physical pieces of debris. Is that just in Ghost Recon? Or did I miss something?

  3. rae Says:

    I think you’re right Mike. It looks to me like the PhysX effects were just tacked-on eye candy in Ghost Recon; rushed out the door so the game could get the “PhysX” stamp on its box. PhysX is getting a lot of hype, and having that in the game causes lots more people to buy it.

    I think to really see how good the PhysX engine is, we need to see a game that uses all of its abilities (like Cell Factor).

  4. Iain Says:

    While it might be too early to say, I think I am leaning toward Havox FX
    as my choice for a physics solution. Havok FX works on any Shader Model 3.0 compatible GPU. I don’t have the space (well, barely, but heat then becomes an issue) for a PhysX’s card so I would prefer something that would run off of my 7800 GTX 512’s.

  5. rae Says:

    I suppose that a PhysX card requires also having a high-end video card, right? Or is there some benefit that could be had with something older, like say an ATi 9800 Pro?

  6. iainb Says:

    PhysX requires an add-in graphics card supporting Microsoft ®DirectX® 9.0 Shader Model 2.0 or higher. The 9800 Pro does support Shader Model 2.0 so it will work with the PhysX technology. Cool!

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