why isn't texturing perspective correct?

vigabrand · July 4th, 2003

How come no one uses perspective correct texturing in this or any other psx emu? Instead they use ugly wobbly affine texturing. Are the developers just trying to be more authentic to the real psx? Does anyone know of any emulator or plugin that enables perspective correct texturing?

**fivefeet8** · July 4th, 2003

Psx emus don't have perspective correction because the actual psx hardware doesn't have a z-buffer. For such a thing to be possible, you need to HLE the psx which would be far less compatible than current psx emus.

vigabrand · July 7th, 2003

Why should a z-buffer be needed? I would think that all the graphics hardware would need would be a z value for every vertex.

**fivefeet8** · July 7th, 2003

Exactly. No z buffer, no z-value. The psx doesn't use z-values.

**n_w95482** · July 7th, 2003

So is that the reason polygons warp in most games?

**Yeloazndevil** · July 7th, 2003

Quote:

Originally Posted by n_w95482

So is that the reason polygons warp in most games?

yup I don't like it, but I moved on from PSX games

F-3582 · July 7th, 2003

Quote:

Originally Posted by n_w95482

So is that the reason polygons warp in most games?

That polygon warping is caused by the original resolution (320*200) that is used to render 3D graphics. If you played the games in 320*200, you wouldn't see any jumping.

**fivefeet8** · July 7th, 2003

Quote:

Originally Posted by F-3582

That polygon warping is caused by the original resolution (320*200) that is used to render 3D graphics. If you played the games in 320*200, you wouldn't see any jumping.

Yeah. But that's one of the things perspective correction would fix. Actually, even at the exact psx resolution, you will still see warping graphics. I see it on the real psx on the TV. Its just more evident at higher resolutions on PC monitors. The TV hides it pretty well but not totally.

**Kane** · July 7th, 2003

You guys are talking two different things here. Perspective correction <> sub pixel accuract IIRC
The problem with the jumpy polys is because the PSX lacks sub pixel accuracy, IIRC, so therefore whatever res you are ing, the coordinates are still worked out for a 320x240 screen and simply scaled up.
Perspective correction would sort out the warping textures, which as ff8 said, requires a Z-buffer which neither does the PSX have or were the games on it designed for.

July 4th, 2003	#1 (permalink)
vigabrand Registered User Join Date: Jul 2003 Posts: 2	why isn't texturing perspective correct? How come no one uses perspective correct texturing in this or any other psx emu? Instead they use ugly wobbly affine texturing. Are the developers just trying to be more authentic to the real psx? Does anyone know of any emulator or plugin that enables perspective correct texturing?

July 4th, 2003	#2 (permalink)
fivefeet8 &-)---\|--< Join Date: Apr 2001 Location: Smallville Posts: 7,582	Re: why isn't texturing perspective correct? Psx emus don't have perspective correction because the actual psx hardware doesn't have a z-buffer. For such a thing to be possible, you need to HLE the psx which would be far less compatible than current psx emus. __________________ Play emulated games online Main Rig\|\|Intel Q6600@3.2 ghertz\|4x1gb DDR2 1066\|Asrock 1600sli 110db LGA 775\|EVGA 8800gtx@620/1450/975\|2x Seagate 160gb SATA150 Raid0\|250 gb Samsung SATA2 HD\|Seagate 7000.10 500gb HD\|NEC 3520 4x/8x DVD+R/RW DL burner\|Antec TP 650 watt\|40" Sony Bravia 1080p\|20.1" 5ms LCD 1680x1050 Native\|Logitec 5.1 Speaker System w/15" Sub\|Dual Boot Winows XP Pro/Vista 64bit\|\| 2nd Rig\|\|Athlon64 x2 3800+\|2x1 gig PC3200\|BFG Geforce 6800 Ultra OC @450/1250 agp\|60 gig Maxtor IDE HD 7200 RPM\|40 gig Maxtor IDE HD\|Asrock Dual SATA2\|Silver Aluminum ATX\|17" LCD\|\| 3rd Rig\|\|Athlon Xp 2800+\|1.5 gig PC2700\|BFG GeforceFx 5900 Ultra OC agp\|100 gig Maxtor SATA HD\|NF7-s rev2.0\|Nvidia Soundstorm MCP\|19" CRT\|\|

July 7th, 2003	#4 (permalink)
fivefeet8 &-)---\|--< Join Date: Apr 2001 Location: Smallville Posts: 7,582	Re: why isn't texturing perspective correct? Exactly. No z buffer, no z-value. The psx doesn't use z-values. __________________ Play emulated games online Main Rig\|\|Intel Q6600@3.2 ghertz\|4x1gb DDR2 1066\|Asrock 1600sli 110db LGA 775\|EVGA 8800gtx@620/1450/975\|2x Seagate 160gb SATA150 Raid0\|250 gb Samsung SATA2 HD\|Seagate 7000.10 500gb HD\|NEC 3520 4x/8x DVD+R/RW DL burner\|Antec TP 650 watt\|40" Sony Bravia 1080p\|20.1" 5ms LCD 1680x1050 Native\|Logitec 5.1 Speaker System w/15" Sub\|Dual Boot Winows XP Pro/Vista 64bit\|\| 2nd Rig\|\|Athlon64 x2 3800+\|2x1 gig PC3200\|BFG Geforce 6800 Ultra OC @450/1250 agp\|60 gig Maxtor IDE HD 7200 RPM\|40 gig Maxtor IDE HD\|Asrock Dual SATA2\|Silver Aluminum ATX\|17" LCD\|\| 3rd Rig\|\|Athlon Xp 2800+\|1.5 gig PC2700\|BFG GeforceFx 5900 Ultra OC agp\|100 gig Maxtor SATA HD\|NF7-s rev2.0\|Nvidia Soundstorm MCP\|19" CRT\|\|

July 7th, 2003	#5 (permalink)
n_w95482 Administrator Join Date: Apr 2003 Location: California Posts: 4,684	Re: why isn't texturing perspective correct? So is that the reason polygons warp in most games? __________________ Main PC: DFI LAN Party nF4 SLI-DR Expert w/406-bta BIOS, AMD Opteron 165 (CCBBE 0615 EPMW) @ 3 GHz (334x9), 1.55v w/D-Tek Fuzion WB; 2x1 GB OCZ PC4000 EB Plats @ 250 MHz, 3-3-2-8, 3:4, 2.7v; ATi Radeon X1900XT 512 MB @ 668/855 w/DD Tyee WB, 150 GB WD Raptor, 4x500 GB WD RE2 (RAID 10), SB Audigy 2 ZS, 700w OCZ GameXStream, CM Stacker 810, Windows XP Pro

July 7th, 2003	#9 (permalink)
Kane 邪魔ゎ指せない Join Date: Jan 2002 Location: Gosport, England Posts: 26,255	Re: why isn't texturing perspective correct? You guys are talking two different things here. Perspective correction <> sub pixel accuract IIRC The problem with the jumpy polys is because the PSX lacks sub pixel accuracy, IIRC, so therefore whatever res you are ing, the coordinates are still worked out for a 320x240 screen and simply scaled up. Perspective correction would sort out the warping textures, which as ff8 said, requires a Z-buffer which neither does the PSX have or were the games on it designed for. __________________ >Site Live< Pop over to my site for help with setting up PSX emulators. Help for the Final Fantasies and other RPGs avalaible Celes: (Desktop) Athlon 64 X2 4200+, 2Gb 400MHz DDR Ram, MSI K8N Platinum, GeForce 8800 GTS 320Mb, 500Gb RAID HDD, Vista Business Erika: (MCPC) Athlon XP 2400+, 1Gb 400MHz DDR Ram, geForce 6800 256Mb, 80Gb Hdd, XP 2005 MCE Kimiko: (Desktop 2) Athlon 64 3000+, 512Mb 400MHz DDR Ram, Asus K8V, geForce 6800 128Mb

July 7th, 2003	#3 (permalink)
vigabrand Registered User Join Date: Jul 2003 Posts: 2	Why should a z-buffer be needed? I would think that all the graphics hardware would need would be a z value for every vertex.

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