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GSDX: Upscaling -  [Bug Report] God Of War 2 - Half pixel offset Broken in dx 11?
#21
(02-10-2016, 10:32 AM)yoshijin Wrote: Regarding the HPO hack I have this feeling that it overcompensates for the misalignment. This leads to white/whitish upper and left borders, best appreciated in fullscreen in games, as in the screenshot of SotC. (I have pasted the screenshot on a black background to make it noticeable)

Please ignore if it is an expected behaviour or known bug.  Unsure

Do you know what resolution the game was running at in your screenshot?

The white lines are probably due to upscaling - unless HPO behavior is close to that of upscaling. In GT4, I just tested DX11/OGL renders, and HPO or not; non-native resolutions cause white lines (or rainbow with HW depth Tongue ) just like you are describing here.
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#22
It was running at 3X native. Sorry forgot to mention that.
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#23
I think I get it. The PS2 might had deliberately used that little amount of misalignment to provide some sort of antialiasing or post processing meant for TVs as Bob said earlier, and upscaling the res in PCSX2 just multiplies that effect leading to noticeable rainbow effect / white lines.
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#24
Rainbow effect is due to interpolation of the depth as color. Ideally we should disable interpolation for depth texture. But I think it will better to avoid the rescaling in the first place. It is a limitation of my depth implementation but it could be improved.

However I think there is something wrong with the hack. If I remember correctly GoW uses this effect.
* scale down by 2x the RT
* Reapply the smaller RT on top of the big RT with bi-linear interpolation.
The effect requires than 2n pass is done with a half-texel offset (due to the bi-linear interpolation).

When you apply scaling of 2x, you apply a linear transformation of 2x on all sizes. So if you have a texture of size 500, the GPU texture will be 1000. Which is equivalent to a texture with pixels that are 2 times smaller. Unfortunately the effect isn't linear, it requires a half-texel offset.

Without the hack, the 0.5 GS texel will become a 0.5*2 = 1 GPU texel. It is bad we need a half-texel offset not 1. So ghosting
With the hack, 0.5 GS texel is removed (IIRC). So it will become (0.5-0.5)*2 = 0 GPU texel. Bad again the effect will likely create a small overlay. It would be more like the PS2, if only a 0.25 GS texel were removed. But the main issue remains, how to detect rendering that need a non-linear scaling operation...
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#25
I had issue with floors that doesn't appeared and just ended up with reflections so i had to play the game in software mode.
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#26
i fixed using agressive CRC.
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#27
This should be retested with the new HPO hack. I don't own this game unfortunately.
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#28
This might be related, but it happens also in software mode.
Some resolution lines are completely missing from x1 native res, it might be wrong frame buffer size detection..?
https://github.com/PCSX2/pcsx2/issues/2257
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#29
(01-22-2018, 07:45 AM)James-F Wrote: This might be related, but it happens also in software mode.
Some resolution lines are completely missing from x1 native res, it might be wrong frame buffer size detection..?
https://github.com/PCSX2/pcsx2/issues/2257
That's a completely unrelated issue.
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#30
(01-22-2018, 12:12 AM)CK1 Wrote: This should be retested with the new HPO hack. I don't own this game unfortunately.

How do I use the HPO hack? I'm having the same issues mentioned in this thread, including the weird lines while swimming under water. I'm using version PCSX2 1.4.0


[Image: MP2t13i.jpg]
[Image: tiCP4Zm.jpg]
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