MAMEWorld Central >> News
View all threads Index   Flat Mode Flat  

Bart T.
Reged: 01/07/06
Posts: 194
Send PM
Re: And the next top model is...
04/02/11 03:59 AM


Anything that causes the frame rate to drop substantially is due to the graphics engine (as opposed to apparent slow down in the game logic, which is not reflected in the emulator's frame rate and is caused by CPU timing inaccuracy). The graphics engine frequently encounters a few common "problems":

1. Large polygons; especially on video hardware that doesn't perform too well to begin with or can just barely achieve 60 FPS in the first place. I think this might be due to the complexity of the fragment shaders creating some sort of fill-rate problem. On my development PCs, which cannot achieve anywhere close to 60 FPS on Daytona 2, the frame rate drops substantially -- sometimes by nearly a factor of 2 -- when the camera pans close to the vehicles in the attract mode sequences. Clearly not a geometry-related problem.

2. Too much geometry. I removed instrumentation code to keep track of the complexity of scenes a long time ago, so I don't know how much of a problem this really is. Generally, scenes aren't that complex by today's standards. I haven't checked, but this may be the cause of slowdown in the Star Wars trench scene and just before, when the tie fighters are descending into the trench. Model 3 has automatic geometry level-of-detail control, which usually isn't very important, but it's possible that it's being put to extensive use here. Supermodel always selects the most complex level of detail.

3. Texture uploads. Due to a bug in my caching algorithm somewhere, I play it safe each time a texture is uploaded and re-upload the entire 2048x2048 texture sheet (individual textures range from 32x32 to 512x512, and are usually somewhere in the middle of that range). Generally, games pre-load textures, but Step 2.x games often swap new ones in during game play. Daytona USA 2 and Sega Rally 2, for example, always do this in the same parts of the track.

3. Weird scene data. This is what's killing Harley, ECA, and Ocean Hunter, and it also seems to happen in Daytona 2 Power Edition in the desert segment of the advanced track. The scene database is a hierarchical structure that is traversed recursively and sometimes, infinite loops appear. Well-behaved games don't have more than a dozen or two levels of nesting, but some of the Step 2.x games have several hundred (almost certainly a problem with our current understanding of these structures).


Scenarios 2 and 3 are probably what you're seeing the most of.

If you play the Daytona 2:PE tracks in reverse (hold start during course selection, I think), you'll see that most of the geometry disappears. It's a scene database traversal problem.


Bart







Entire thread
Subject Posted by Posted on
* And the next top model is... Bart T. 04/01/11 09:48 AM
. * Discuss this in MAME Chat from here out. Closed because it's no longer news and it's getting a little creepy. (nt) kthx SmitdoggAdministrator  04/05/11 11:15 PM
. * any ClrMAME .dat file available ? CiroConsentino  04/05/11 07:46 PM
. * Re: And the next top model is... Cable  04/04/11 11:36 PM
. * Re: And the next top model is... Elratauru  04/04/11 11:42 PM
. * Re: And the next top model is... BIOS-D  04/04/11 11:20 PM
. * Re: And the next top model is... c0de  04/04/11 10:09 PM
. * Re: And the next top model is... R. Belmont  04/04/11 10:57 PM
. * Re: And the next top model is... c0de  04/05/11 08:04 PM
. * Re: And the next top model is... GraphicArts  04/05/11 09:55 PM
. * Re: And the next top model is... Bart T.  04/05/11 12:02 AM
. * Re: And the next top model is... xxanderr1234  04/05/11 04:06 AM
. * Re: And the next top model is... Elratauru  04/05/11 05:55 AM
. * Re: And the next top model is... xxanderr1234  04/05/11 01:48 PM
. * Thanks for all the great feedback but.. Bart T.  04/04/11 10:07 PM
. * Re: Thanks for all the great feedback but.. gregf  04/04/11 10:22 PM
. * Re: And the next top model is... karadaniano  04/04/11 09:16 PM
. * Re: And the next top model is... GraphicArts  04/04/11 09:46 PM
. * Re: And the next top model is... Cyberzinho Punk  04/04/11 03:53 AM
. * 64-bit Windows build now available. Bart T.  04/03/11 08:56 PM
. * Re: 64-bit Windows build now available. Outrun2006  04/04/11 07:47 PM
. * Re: 64-bit Windows build now available. bart lover  04/04/11 07:54 PM
. * Re: 64-bit Windows build now available. RetroRepair  04/04/11 08:11 PM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 09:06 PM
. * Re: 64-bit Windows build now available. bart lover  04/04/11 10:19 PM
. * Re: 64-bit Windows build now available. RetroRepair  04/04/11 09:57 PM
. * Re: 64-bit Windows build now available. GraphicArts  04/04/11 10:06 PM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 10:05 PM
. * Re: 64-bit Windows build now available. Outrun2006  04/04/11 09:43 PM
. * Re: 64-bit Windows build now available. CrapBoardSoftware  04/04/11 11:32 PM
. * Re: 64-bit Windows build now available. CrapBoardSoftware  04/04/11 09:19 PM
. * Re: 64-bit Windows build now available. gregf  04/04/11 10:30 PM
. * Re: 64-bit Windows build now available. CrapBoardSoftware  04/04/11 11:29 PM
. * Re: 64-bit Windows build now available. Elratauru  04/04/11 04:25 AM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 05:29 AM
. * Re: 64-bit Windows build now available. Elratauru  04/04/11 09:40 AM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 05:37 PM
. * Re: 64-bit Windows build now available. bart lover  04/04/11 06:30 PM
. * Re: 64-bit Windows build now available. GraphicArts  04/04/11 06:44 PM
. * Re: 64-bit Windows build now available. bart lover  04/04/11 03:18 PM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 05:31 PM
. * Re: 64-bit Windows build now available. GraphicArts  04/04/11 05:11 PM
. * Re: 64-bit Windows build now available. Bart T.  04/04/11 05:29 PM
. * Re: 64-bit Windows build now available. GraphicArts  04/04/11 05:48 PM
. * strange performance Chine  04/03/11 04:58 PM
. * Re: strange performance Chine  04/03/11 07:40 PM
. * Re: strange performance zambr  04/03/11 05:28 PM
. * Re: strange performance Chine  04/03/11 05:38 PM
. * Re: strange performance Elratauru  04/03/11 06:10 PM
. * Re: strange performance GraphicArts  04/04/11 09:12 PM
. * Re: strange performance GraphicArts  04/04/11 07:21 PM
. * Re: strange performance zambr  04/03/11 05:59 PM
. * Re: strange performance Anonymous  04/04/11 03:53 AM
. * Re: strange performance GraphicArts  04/03/11 08:04 PM
. * Re: strange performance GraphicArts  04/03/11 06:39 PM
. * Re: strange performance luke2fr  04/03/11 07:14 PM
. * Re: strange performance R. Belmont  04/03/11 08:15 PM
. * Re: strange performance GraphicArts  04/03/11 10:44 PM
. * Re: strange performance GraphicArts  04/03/11 08:50 PM
. * Re: strange performance R. Belmont  04/03/11 11:30 PM
. * Small source update Bart T.  04/03/11 12:42 AM
. * Re: Small source update CiroConsentino  04/03/11 02:51 PM
. * Re: Small source update zambr  04/03/11 03:27 PM
. * Re: Small source update CiroConsentino  04/03/11 08:00 PM
. * Re: And the next top model is... Cyberzinho Punk  04/02/11 09:17 PM
. * Re: And the next top model is... karadaniano  04/02/11 08:38 PM
. * Re: And the next top model is... ShengLong  04/02/11 10:14 PM
. * Re: And the next top model is... Bart T.  04/02/11 11:01 PM
. * Re: And the next top model is... zambr  04/02/11 10:52 PM
. * Re: And the next top model is... GraphicArts  04/02/11 07:26 PM
. * Re: And the next top model is... GraphicArts  04/02/11 08:06 PM
. * Re: And the next top model is... Bryan Ischo  04/02/11 03:33 PM
. * Re: And the next top model is... Vas Crabb  04/02/11 04:19 PM
. * Re: And the next top model is... GraphicArts  04/02/11 03:55 PM
. * Re: And the next top model is... R. Belmont  04/02/11 05:45 PM
. * Re: And the next top model is... GraphicArts  04/02/11 10:01 PM
. * Re: And the next top model is... etabeta  04/03/11 12:44 PM
. * Re: And the next top model is... Bart T.  04/02/11 11:04 PM
. * Re: And the next top model is... pjay  04/02/11 11:25 PM
. * Re: And the next top model is... karadaniano  04/03/11 12:20 AM
. * Re: And the next top model is... Bart T.  04/03/11 12:52 AM
. * Re: And the next top model is... pjay  04/03/11 08:09 AM
. * Re: And the next top model is... R. Belmont  04/03/11 11:31 PM
. * Re: And the next top model is... GraphicArts  04/05/11 10:02 PM
. * Re: And the next top model is... karadaniano  04/05/11 11:18 PM
. * Re: And the next top model is... R. Belmont  04/03/11 12:37 AM
. * Re: And the next top model is... firebricks  04/03/11 09:02 PM
. * Re: And the next top model is... Dr. Spankenstein  04/02/11 11:40 PM
. * Re: And the next top model is... karadaniano  04/01/11 11:43 PM
. * Re: And the next top model is... Ceto  04/01/11 10:27 PM
. * feature request - mouse on course select screens zambr  04/01/11 09:14 PM
. * Re: And the next top model is... GraphicArts  04/01/11 08:52 PM
. * Re: And the next top model is... pjay  04/01/11 06:58 PM
. * Re: And the next top model is... GraphicArts  04/01/11 05:43 PM
. * Re: And the next top model is... Bart T.  04/01/11 05:52 PM
. * Re: And the next top model is... MAMu_  04/01/11 06:39 PM
. * Re: And the next top model is... GraphicArts  04/01/11 05:59 PM
. * Re: And the next top model is... Bart T.  04/01/11 06:11 PM
. * Re: And the next top model is... GraphicArts  04/01/11 06:23 PM
. * sound? VirtuaIceMan  04/01/11 05:28 PM
. * Re: sound? R. Belmont  04/01/11 06:39 PM
. * Re: And the next top model is... Cable  04/01/11 04:57 PM
. * Re: And the next top model is... AnimalBear  04/01/11 04:27 PM
. * Re: And the next top model is... HowardC  04/01/11 02:25 PM
. * Re: And the next top model is... Bart T.  04/02/11 12:05 AM
. * Re: And the next top model is... HowardC  04/02/11 05:00 AM
. * Re: And the next top model is... Anonymous  04/02/11 02:03 AM
. * Re: And the next top model is... R. Belmont  04/01/11 02:23 PM
. * Re: And the next top model is... belegdol  04/02/11 09:22 AM
. * Re: And the next top model is... R. Belmont  04/02/11 11:29 AM
. * Re: And the next top model is... belegdol  04/02/11 12:39 PM
. * Re: And the next top model is... Solstar  04/02/11 12:55 PM
. * Re: And the next top model is... belegdol  04/02/11 01:11 PM
. * Re: And the next top model is... R. Belmont  04/02/11 05:43 PM
. * Re: And the next top model is... belegdol  04/02/11 06:28 PM
. * Re: And the next top model is... R. Belmont  04/02/11 11:29 AM
. * Re: And the next top model is... Outrun2006  04/02/11 10:35 AM
. * Re: And the next top model is... Bart T.  04/01/11 05:12 PM
. * Re: And the next top model is... JacKc  04/01/11 02:08 PM
. * Re: And the next top model is... Elratauru  04/01/11 01:57 PM
. * Re: And the next top model is... zambr  04/02/11 01:14 PM
. * Re: And the next top model is... Anonymous  04/01/11 09:49 PM
. * Re: And the next top model is... GraphicArts  04/01/11 03:25 PM
. * Re: And the next top model is... Bart T.  04/01/11 05:06 PM
. * Re: And the next top model is... RetroRepair  04/01/11 03:34 PM
. * Re: And the next top model is... GraphicArts  04/01/11 04:02 PM
. * Re: And the next top model is... GraphicArts  04/01/11 02:16 PM
. * Re: And the next top model is... HowardC  04/01/11 02:05 PM
. * Re: And the next top model is... Bart T.  04/01/11 05:09 PM
. * Re: And the next top model is... Elratauru  04/01/11 02:46 PM
. * Re: And the next top model is... Bart T.  04/01/11 05:23 PM
. * Re: And the next top model is... GraphicArts  04/01/11 02:51 PM
. * Re: And the next top model is... RetroRepair  04/01/11 02:56 PM
. * Re: And the next top model is... Bart T.  04/01/11 05:17 PM
. * Re: And the next top model is... GraphicArts  04/01/11 05:25 PM
. * Re: And the next top model is... VirtuaIceMan  04/01/11 03:01 PM
. * Re: And the next top model is... CiroConsentino  04/01/11 01:53 PM
. * Re: And the next top model is... Elratauru  04/01/11 01:09 PM
. * Re: And the next top model is... Bart T.  04/01/11 11:22 PM
. * Re: And the next top model is... Elratauru  04/02/11 03:18 AM
. * Re: And the next top model is... Bart T.  04/02/11 03:59 AM
. * Re: And the next top model is... Ville Linde  04/01/11 11:50 PM
. * Re: And the next top model is... Bart T.  04/02/11 12:03 AM
. * Re: And the next top model is... GraphicArts  04/01/11 01:21 PM
. * Re: And the next top model is... GraphicArts  04/01/11 12:24 PM
. * Re: And the next top model is... GraphicArts  04/01/11 01:09 PM
. * Re: And the next top model is... Elratauru  04/01/11 12:21 PM
. * Scchhwweeett! - nt Naoki  04/01/11 12:04 PM
. * Re: And the next top model is... Elratauru  04/01/11 11:56 AM
. * Re: And the next top model is... MAMu_  04/01/11 11:27 AM
. * Re: And the next top model is... GraphicArts  04/01/11 11:43 AM
. * Re: And the next top model is... GraphicArts  04/01/11 11:46 AM
. * Re: And the next top model is... Elratauru  04/01/11 11:09 AM
. * Re: And the next top model is... Ziggy100  04/01/11 11:39 AM
. * Re: And the next top model is... GraphicArts  04/03/11 05:53 PM
. * Re: And the next top model is... MAMu_  04/01/11 10:51 AM
. * Re: And the next top model is... pjay  04/01/11 10:26 AM
. * Re: And the next top model is... Outrun2006  04/01/11 10:29 AM
. * Re: And the next top model is... HowardC  04/01/11 10:52 AM

Extra information Permissions
Moderator:  John IV, Tafoid 
5 registered and 23 anonymous users are browsing this forum.
You cannot start new topics
You cannot reply to topics
HTML is enabled
UBBCode is enabled
Thread views: 28769