PSP Poly Counts...

#1

Well, it’s been bothering the heck out of me recently, The 3d departmenthas recently been at a loss, Wile we have all of our models we dont have a safe number for poly counts. Myself as a level designer, I’d really like to know what a limit is aswell. (We dont have access to the dev kit, or connection to sony)

So far all of our test are based on a low end machine with a TNT2 card with similar specifacations to the PSP and buffered as close as we can get to the specs.

But the hardware is entirely different from a PC so our scale may be off in either direction.

I read before that the PSP can render about 300,000 Polygons per frame (In theory) but what is a realistic number?

The project is a first person shooter

Right now our model poly counts are similar to HL1

Weapons:
view model’s - 400 max (average 345)
World models - 100 max

Player models:
main characters - 800 max
Side characters - 650 max
enimies - 700 max

Vehicles:
Tanks/apc’s - 1500 max (locked view when driving to reduce to around 400 polygons)
jeep’s - 1000 max ( also locked but only to the back)

World’s are only limited to scene’s large areas are limited so about 3000 polygons per area which is a bit hindersome of cource we need better numbers to create larger areas…

So How far are we off? these are from out tests to maintain 60 frames per second using these poly counts on our test machine.

#2

The number I hear tossed around the most is 80,000, that’s with some optimization but also a lot of effects and animation and textures and stuff. Probably a safe target!

#3

Thanks, Currently we are looking at how much we are using up and that seems rather close to our estimates.

I appreciate your help

#4

I was able to contact a developer from DC-Studios and we discuss possibilities.

80k polygons would be a stretch. you could get about 30 fps and thats with some keen optimization.

I discussed what I had he said that its possible but what would be best is a proper cliping system and limiting the large views

a 45,000 triangle count would be safest (includes AI, animation, and weak physics) a variation of frames between 30 and 60 frames, but of cource this is an estimate. (this is for any given view area not content poly limit)

With proper optimization this is more than enough, as I have managed to test it. we found a large number of wasted polygons on our models and we created 2 LOD’s for models wile the PSP can create LOD’s for the textures by itself.

Its all about how you manage it I guess…

Most PSP games wont be touching this, not unless they are well experience PS2 developers.

One other thing to mention, the triangle count can rise in the future. due to sony clocking the PSP to lower frequencies to conserve battery. This is expected to change to the default clock speeds (about 3/2 the original clock speeds) at the later part of the PSP’s life span some sugest that sony is doing this to get the best out of the PSP. even at the end of its life span.

#5

The PSP proc is currently under-clocked at 222mHz.This is set by the firmware but individual programs can set the clock speed back to it’s designed speed of 333mHz. Some homebrew emulaters do this as a brute force way of getting old SNES games running at their original speed (on psp’s with firmware 1.0 or 1.5 only).
The rumor is that when Sony release GT4 (soon!) that they’ll set it back to 333mHz because they need GT4 to look and run amazing (maybe it doesn’t run well at 222mHz at the moment anyway?). Another rumor is that Sony will also release a new higher capacity battery in parallel to the GT4 release (presumedly so people don’t complain that after buying GT4 their batterys don’t last long?)
Whether the clock change for GT4 will just be temporary while the game is running or Sony release a new firmware on the UMD that keeps the psp @333mHz remains to be seen.

#6

They released Info on it, I cant remember if they released it in Japan.

Yes the proc is underclocked… so is the GPU, their way at attacking the batterylife problem.

But if you think about it its like strapping 2 PDA’s togeather and making them run on 2 AA batteries… It’s going to eat through them.

Yes when Sony Clocks the processor back up this polycount will increase slightly but Its not sugested, mainly because you are buggering on the 60 FPS line or even 30 if you are touching the limit like a large person in the air ducts… The project I’m working with is optomizing it to ensure it works on 222mhz and 111mhz(GPU) with a minimum of 60 FPS with 30 FPS being the extream Spike… but we always hope to be after the 333mhz curve…

#7

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