forums.ps2dev.org

[Grom]

Hi, guys

At first, thanks for a great work - PSPSDK.

I'm playing with it now. My job is to determine the performance of PSP to make 3D games.

At this time, I found that I can draw ~30K of textured lit triangles at 20 fps. Is it a limit or I can draw more triangles at 20 fps?

I'm using Holger's PSPgl.
And right now my demo consists of 64 3D tanks turning over themselves. So as you can figure out, trinagles are not so big.

Please, give me any real info about PSP performance.

Thanks in advance.

[jsgf]

Well, its fairly hard to tell what you're actually measuring. 30k triangles/frame sounds a bit low, but I haven't really done a lot of benchmarking yet.

If you use the my PSPGL (http://www.goop.org/psp/gl), you can use the PSP_statistics extension to get a bit of information about how long the library is spending waiting on the hardware vs. total time. This will tell you whether you're CPU bound or GE bound.

Are you using begin/end or vertex arrays? In general, vertex arrays will give you the best performance. With goop.org PSPGL, you can use compiled vertex arrays and vertex array objects to put the array data into the GE's VRAM, which may or may not help.

Are you using indexed arrays or not? What primitive are you drawing (tris, strips or fans)?

What kind of textures are you using? Are you using mipmaps? goop.org PSPGL supports texture objects, and will put your textures into VRAM which could give you some performance improvement. It does not currently swizzle textures, which people say give a performance boost.

What kind of texture format are you using? In general the PSP is happier with fewer bits/pixel. Rather than using 32-bit RGBA, try a 16-bpp format, or use an indexed 8 or 4bpp format.

How many lights are you using? It seems that using 4 lights is more than 4x the cost of using a single light. Are you using spotlights or directional?

[Grom]

I'm using a vertex array. It is compiled.
My model is an indexed mesh with 410 faces and about 500 vertices and I draw it as tris.

Texture is a raw 128x128 RGB file withour mipmaps.

There is only one directional light.

So new questions here:
Will mipmaps increase speed of rendering?
Do you have any information about vertex cache? Maybe I need to sort vertices&indices in a specific order?
Does texture switch have a big effect to perfomance?

Please tell me which perfomance do you have if you think 30K is a bit low.

P.S. To be honest, I have built my sample on you sample "test-bezier". I ported it to C++, added model and removed a bezier mesh (but I plan to turn it on again). My task is to discover how many details I can have in scene with heightfield and some war units like tanks, troops.

[jsgf]

[Grom]

OK, I will try to make my best on the PSP. I will report here about my achievements. I also ask you to post here your own info and tricks about PSP possibilities.

[Grom]

-- posted 2 times by a mistake --
please,delete this message

[CyberBill]

Most 3D engines on the PSP are seeing performance around 1mil polys a second. You are seeing about 600,000 polys a second (30k * 20fps)... Definately some room for improvement. :)

However most games are not a bunch of models, its mostly ground terrain and stuff.

[Grom]

I have interesting problem.

Bezier patches a good for heightfield terrain. But how to calculate a height at this landscape? My tank now sometimes fly over landscape and sometimes running beneath it.

There is also another problem:
PSPglreport an error here:

[jsgf]