max t&l verticies?

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Stellar
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max t&l verticies?

Post by Stellar »

I havent started developing for psp yet, but im preparing ( currently working on maya -> psp mesh exporter ). Theres something I dont quite understand. The specs tell that the psp is capable of rendering 30M polys per second. given that statement, and that there is only so much ram. How is it possible to store that much data in ram on the psp?

if a single vertex (t&l) consist of a vertex, normal, and uv, that would be 8 floats or 32 bytes. of course, we need 3 of these per face. I am not using indexed verticies, I hear the psp works better non-indexed.

so if I multiply 30,000,000 triangles * 3 verticies * 32 bytes = 2.88 Gigs O_o ... Ive got to be missing something, can someone please fill me in.

thanks for any responses,
-stellar
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chp
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Post by chp »

You're missing a few things, yes:

a) You can use 8-bit and 16-bit input in the vertices aswell.
b) You can kick the same object more than once.

Since you can render maximum 65535 vertices in one go, you can just simply render the same object over and over again with optimal vertex size. You won't reach even near to the maximum value using floats anyway, and that max-value is probably raw performance, which means the resulting triangle might have zero area.
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ector
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Post by ector »

You're also missing that you need to render 60 or 30 times per second, not 1.
http://www.dtek.chalmers.se/~tronic/PSPTexTool.zip Free texture converter for PSP with source. More to come.
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Stellar
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Post by Stellar »

:X heh, yeah that accounts for quite a bit ^^'

Ild also like to ask what vertex count range you guys stay when developing npc models ( excluding the map, particles, ect... just actors ).

thx, again :D
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LuMo
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Re: max t&l verticies?

Post by LuMo »

Stellar wrote:currently working on maya -> psp mesh exporter
nice!
already did that (mesh only and also colored vertices)
if you need help on that i can help you.
if you find out how to export the uv's (textures) too let me know
(as i can read the uv values, but you can have more than one uv per vertices...)

greets
lumo
PS: if you force 1uv/vertex i fot that too...
PPS: possibly we could join?
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Stellar
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Post by Stellar »

hi Lumo :D

nice to meet a fellow uhh... maya'er. yeah, i originally developed my exporter in mel but i got frustrated at the end when my final version didnt give me correct results and I coundnt do any real debugging to find out why. So i ported over to maya api. ive come along way in leaning how the puzzle goes togeather. as my exporter stands, I can export a maya file with a single mesh ( made of seperate objects (meshes) ) and break those up further by material so I can use transparancy in my rendering loop.
yeah, i got the tex coords. If you want, Ill post the source code if you wanna try to decipher it or modify for you purposes. also, thx for gesturing your assistance, good to find ppl willing to help :)

later,
-stellar
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LuMo
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Post by LuMo »

yeah, i got the tex coords. If you want, Ill post the source code if you wanna try to decipher it or modify for you purposes.
would be really cool!

greets
lumo
"Good artists copy, great artists steal."
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Stellar
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Post by Stellar »

hey man, ill post it in a day or two, I just wanna clean up a few things first :).
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Stellar
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Post by Stellar »

ok, heres my exporter. fyi, its not done yet, not nearly complete. so thats just a heads up until i post a complete version. soo...

the basic formula is as follows

export all materials

export all meshes
{
break up meshes by material

export data specified in options.cfg
}

use the options.cfg file to set parameters. this is real basic, so just drag a maya file on the exe or open dos and supply a path name.

output file does not have to be specified, but it can be (either from cfg file or cmd prompt ).

input file is specified either from cfg or cmd prompt or drag and drop, and must be specified.

binary doesnt really work yet, its not tested. debug can help you understand how the file is build.

indexed will generate indexes and fewer verticies if possible

exports will let you specify what you want exported, right now thats just normals, uvs and points. you specify the order by the order they appear in the cfg file.

notes------------

i believe the uvs are exported correctly, they need a formula if the file is to imported for directx, you can see it commented out

again, this is a work in progress, so its not perfect yet.

it does not support------------------

multiple meshes ( not correctly anyway )
bones ( yet )
animation ( yet )
weighted verticies ( yet )

tips------------------

you may want to freeze your transformations before exporting, that way your transform will be the identity matrix, which is always easier on the math.

heres the source, visual studio 2003
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LuMo
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Post by LuMo »

thanks i'll check it (although i am using mel to export my models)
think mel works in ple too (have to test that...)
mel is fucking slow at high res (but psp cant handle that anyway...)

greets
lumo
"Good artists copy, great artists steal."
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Stellar
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Post by Stellar »

well, i started using mel, and i was driven to the api ¬_¬ my last mel source wasnt generating the correct results and it took forever for me to map out, debug, and determine why. in the end tho, im much happier with the api, so youll have a good start if you need something to fall back on.
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