Multi core processor support in CoD

[Skinny]

I havent coded in like 20 years, but mazex is spot on. People who think creating a game engine that can make proper use of 2/4/8 or more threads is easy need to do some reading. There is a reason most software today barely scales beyond 2 threads. Heliocon, maybe you should just try it.

What I am curious about is the physx claim, that it would be useless for flightsims. I dont know about the API, maybe that is useless, but calculating the physics (rather than PhysX) does seem something that could benefit greatly from GPGPU (CUDA or OpenCL).

[Heliocon]

Originally Posted by Skinny

I havent coded in like 20 years, but mazex is spot on. People who think creating a game engine that can make proper use of 2/4/8 or more threads is easy need to do some reading. There is a reason most software today barely scales beyond 2 threads. Heliocon, maybe you should just try it.

What I am curious about is the physx claim, that it would be useless for flightsims. I dont know about the API, maybe that is useless, but calculating the physics (rather than PhysX) does seem something that could benefit greatly from GPGPU (CUDA or OpenCL).

Hey, why dont you read my bloody posts before you comment? I never said it was easy, I infact said it was hard to do. Dont put words in my mouth. I took issue with his definitions of memory which are factually incorrect.

Also physx (which I never mentioned btw as someone implied I did) is mainly geared to particles and cloth/hair etc. It would certainly work for stuff like clouds and smoke that interact with planes passing through, but I dont know of its effects on flight models. CUDA is meh.

[Skinny]

Originally Posted by Heliocon

Also physx (which I never mentioned btw as someone implied I did) is mainly geared to particles and cloth/hair etc. It would certainly work for stuff like clouds and smoke that interact with planes passing through, but I dont know of its effects on flight models. CUDA is meh.

Particles is what its mostly used for, for obvious reasons: many (/most) gamers dont have physx enabled hardware, therefore its used for eye candy that can easily be turned off without affecting actual gameplay.

That doesnt mean its not usable for physics simulation like aerodynamics. Surely you've seen all the hydrodynamics simulations. If it works for water, I dont see why it couldnt work for air:

http://www.youtube.com/watch?v=ok8ThRR-59Q

[Heliocon]

Originally Posted by Skinny

Particles is what its mostly used for, for obvious reasons: many (/most) gamers dont have physx enabled hardware, therefore its used for eye candy that can easily be turned off without affecting actual gameplay.

That doesnt mean its not usable for physics simulation like aerodynamics. Surely you've seen all the hydrodynamics simulations. If it works for water, I dont see why it couldnt work for air:

No reason that I know off, I just dont know how they manage the flightmodel/air interaction. If there "zones"/boxes of air with different property? So If I enter one area I get turbulence or something? Or is it managed dynamically or prodcedually? I have no idea tbh

The main difference is Physx is not really a mechanic focused on physics as much as it is focused on solving and then "presenting" the effects. Its also GPU tied which needs to be rendering. Physx is great, but unless you have a dedicated card its better to buy a second card then have a non physx gpu. Atleast thats what people seem to think on the EVGA forums.

[Skinny]

Originally Posted by Heliocon

No reason that I know off, I just dont know how they manage the flightmodel/air interaction. If there "zones"/boxes of air with different property? So If I enter one area I get turbulence or something? Or is it managed dynamically or prodcedually? I have no idea tbh

The main difference is Physx is not really a mechanic focused on physics as much as it is focused on solving and then "presenting" the effects. Its also GPU tied which needs to be rendering. Physx is great, but unless you have a dedicated card its better to buy a second card then have a non physx gpu. Atleast thats what people seem to think on the EVGA forums.

Actual calculation of airflow over a plane wing and prop is probably many years out. That stuff is so compute intensive super computers struggle with it and may not do it in realtime.

I do remember seeing a video of Rise Of Flight where air movement was visualized with arrows, showing wind, prop wash, thermals and the like. I cant find the video, it was really impressive, and showed that game is modelling airflow to some extend (though probably not to calculate aerodynamic behavior of the plane). I was just guessing stuff like that could be offloaded to the GPU.

As for PhysX as API, I was talking more generally about GPGPU. There is also OpenCL which works on both ATI and nVidia cards.

[The Kraken]

Originally Posted by Skinny

Particles is what its mostly used for, for obvious reasons: many (/most) gamers dont have physx enabled hardware, therefore its used for eye candy that can easily be turned off without affecting actual gameplay.

That doesnt mean its not usable for physics simulation like aerodynamics. Surely you've seen all the hydrodynamics simulations. If it works for water, I dont see why it couldnt work for air

Well air is compressible, water is not PhysX is primarily designed for rigid body physics (the water animation also belongs to that area) and not too useful for more complex problems, although I have to admit I'm not sure what the most current state of the API is.

The bigger problem though is this: the flight dynamics engine is the core of any flight sim. You cannot rely on proprietary solutions like PhysX because you have to make sure it works for everyone, and also the same for everyone. It is much harder to debug, it is additional work even if only parts of the calculations are moved to the GPU and you run the risk of ending up with a dead solution should nVidia decide to drop it one day or maybe go out of business.

[Heliocon]

[QUOTE=The Kraken;217731]Well air is compressible, water is not PhysX is primarily designed for rigid body physics (the water animation also belongs to that area) and not too useful for more complex problems, although I have to admit I'm not sure what the most current state of the API is.

The bigger problem though is this: the flight dynamics engine is the core of any flight sim. You cannot rely on proprietary solutions like PhysX because you have to make sure it works for everyone, and also the same for everyone. It is much harder to debug, it is additional work even if only parts of the calculations are moved to the GPU and you run the risk of ending up with a dead solution should nVidia decide to drop it one day or maybe go out of business.[/QUOTE

Yep I agree, I dont think physx should be in because it hurts ATI users, they need to come up with a standard system, but I dont think Havok will cut it either (specially not for flight modeling).