[ODE] Future of physics processors and IM API

[Pierre-Laurent CHAMBERT]

Do you think a such PPU is doable with some Logic Programmable deives lice 
FPGA?
A custom chip only for Physics might by expensvie to do...
Le Samedi 14 Mai 2005 13:00, David Black a écrit :
> Hi,
>
> I have been thinking about physics hardware and how it might be accessed
> through an API effectivly.
>
> The AGEIA chip looks interesting, except what worries me is that novodex
> is a little too high level and as a result seems less flexible.
>
> I can see a number of levels for physics hardware(just considering the
> joint solver for now).
>
> The simplest would be a hardware implimentation of a gauss seidel or
> jacobi iterator(or even something smarter, like a hybrid
> iterative/dantzig solver or multi grid inspired method). This would be
> relativly simple to create an API for, ie store matrices in shared
> memory and issues requests to process them, with either an error
> tolerance or set number of iterations. Then recieving the results some
> time later.
>
> The next level in sophistication would be a chip which can perform the
> above, but in addition has the ability to build jacobians(and associated
> parameters) from a fixed set of joint descriptions(eg contact, ball and
> socket, slider etc).
>
> After this you get to the next level where you have 'physics shaders',
> in a similar way to GPUs. There function is to build the jacobians(etc)
> on the PPU while being passed joint parameters from the user.
>
> Then there is the integrator, there are many choices for this, but I
> presume something fairly standard would have to be chosen, eg RK4 or
> semi implicit euler etc. Again some sort of shader type language could
> be used, but I am not sure it is so necasery for the integrator.
>
> Following on there is group/island managment and sleeping/autodisable.
> Which is more difficult. The higher you go the more policy you need to
> put in the hardware and the less flexible it becomes.
>
> I just hope AGEIA (or someone else) comes up with a physics chip which
> can be accessed at these levels, rather than only through something like
> novodex(which is great, but not suited to everyones needs and I am sure
> given the chance people could improve upon it).
>
> I also wonder if the AGEIA chip isnt just novodex in the firmware on the
> card and executed by a CPU with some additional hardware. (Anyone
> remember rendition graphics cards?). I just dont think such an approach
> is very scalable...
>
> What are peoples thoughts?
>
> David
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