Polygon rednering problem

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seewan
Posts: 6
Joined: Wed Oct 19, 2005 8:14 pm

Polygon rednering problem

Post by seewan »

I have encounter 3 problem

where can u get a detail explaination of the psp hardware and doc on the pspdev?

1) vertex data format

Is there a fix order in which the data is of the vertex should be?
for example UV come freist then vertex color then normal then vertex position

2) I am loading a file which i exported from 3dmax . I create a memeory for the verteices and copy the file data into the memory area i created

then i draw the vertex array

however i found that not all the array will appear and it take sometime for all the triangle to appear.

sometime it only appear after i press home then cancel to go back to the game . why is this so? is there some special timing for memeory issue i shoudl consider?

thanks
memon
Posts: 63
Joined: Mon Oct 03, 2005 10:51 pm

Post by memon »

The pspgu.h header file is good place to checkout that kind of stuff. The vertex ordering info is also available at the wiki (http://wiki.ps2dev.org/psp:ge_vertex_format) The order is:

* Vertex order:
* [for vertices(1-8)]
* [texture uv]
* [weights (0-8)]
* [color]
* [normal]
* [vertex]
* [/for]

The 'for' stuff means that you can define vertex with multiple values and blend between them using the hardware.

I would guess that the second problem is about cache. You need to either write to uncached address when creating the vertex array, or flush the data chache after you have finished creating the vertex array. Search back a little this forum and you will find that this is the usual solution to any flickering not not appearing problems :) I hope this info eventually finds its way to the wiki, as it is usually the first weird thing to think about when coming from pc platform.
jsgf
Posts: 254
Joined: Tue Jul 12, 2005 11:02 am
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Post by jsgf »

The cache document is at http://goop.org/psp/cache-howto.html. I'll put it on the wiki when I get the chance, but it seems to be down right now.
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