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findankur247

Physics goes absurd when exported to PS2 from windows!

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Hey guys.... We are developing a game for PS2 using a windows based Engine. The physics for the game works fine in the windows mode...but when exported to the PS2 mode..the physics goes wayward....which is absurd!!...we've got no clue about it. Few suspects:: we were getting a bad quickstepper warning....... Maybe there's some difference in the time frames for windows and PS2..... Some math util functions that dont work for PS2...like sqrt...we dont know the list....if anybody does plzz post it...wud b a great help!.... we've got nothing more than that!!...:).... Plz rply guyzz.....we're stuck! Cheers!!!

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Quote:
Original post by Rompa
The PS2 has a single precision floating point sqrt instruction, so I'm not sure what you're on about.


That confused me too, but I think they are asking whether any maths functions don't work, rather than saying they dont.

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What's your physics step size linked to? If it's linked to frame rate, it might be that the PS2 is underpowered compared to your normal development platform, and the frame rate drops, which means larger physics steps and less stable physics.

Try setting the physics step to something constant, like 120 Hz.

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Actually, I would say the PS2 has plenty of power - if coded for "correctly".

If you simply "port" PC code, forget about decent speed.

We skin meshes faster on PS2 using the EE, VU0 and SPR than with an optimized paired-singles implementation on the Wii (which runs > 2x faster than PS2's CPU).

You NEED to code with both code-cache and data-cache in mind, specifically data cache. They're TINY on the PS2. You MUST use the scratchpad for any form of decent performance!

The only math instructions I can immediately think of that the PS2 doesn't have are transcendental functions and an unsigned min and max. This is all from my memory though.

[Edited by - Rompa on July 24, 2009 6:45:11 AM]

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