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Scanline effects, LCDs, and a sort of recant
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Blanka:
If you look at the video with original resolution vs. overlays, and you look at the first on a high-res LCD, then you see what COULD be possible on an LCD. That quality is amazing.
Problem is that no-one ever did the overlaying right. The problems with the overlays you see today are:
- The overlay scanlines do not match the game scanlines. It is a simple 4x4 pixel pattern put over a blurred upscaling of the image.
- Overlays dim parts of the image to black to give the idea of scanlines. Well it should be more like a linear raster in printing. If the brightness is high, the lines should get wider and finally stick together, if it is dark, they should look loose.

So to do it right, it involves a three-stage rocket:
- Render the frame at original resolution
- Upscale it 5 times blocky (1200x1600, a common LCD resolution is 5 times 240x320, a common arcade resolution)
- Apply a 5x5 pixel tridot rendering, and let the bright pixels glow a little onto the surrounding pixels. Do this in a way that the AVERAGE colour of ALL 25 pixels is the SAME as in the blocky upscaling (it's a hard calculation, but it can be done)
- Scale the result down to the resoltion of the screen

It takes some OpenGL/OpenCL power, but it is no problem for any 6600GT/X1300+ videocard.
Blanka:

--- Quote from: Loafmeister on January 31, 2009, 03:04:35 pm ---Agreed. Scanlines was never something the devs intended, it was something they had to live it.
--- End quote ---
Today you have Arcade VGA and Bubalicious CRT tubes
Tomorrow we vacuum-form our 300dpi OLED foils on our dead tubes.
The Mame DEV's should start worrying about scanlines. If they want to be accurate, scanlines are going to be a part of that. Even worse: some people should document every pixel characteristic of monitors used in the original cabs, and make specific scaling textures for that.
Ummon:
Sounds good, Blanka. I think they're thinking about it. It's just not a hot topic. Aaron is thinking about everything, I think. However, check out the current Kangaroo, and pay special attention to the 'trees' and 'foliage'. There are what appear to be natural scanlines at stock settings, but no (apparent) dimness. Aaron said that was due to increasing the accuracy of the hardware emulation. HMM.
ivwshane:
I stopped by an arcade today (well it had arcade games) and I compared the different monitors to see how close my cabs display came to emulating them. I was pretty surprised to see any difference but even more surprised that the displays didn't look anything like I remembered. So I fired up mame32 to see how the built in affects compared to the real thing.

These three came the closest to looking the most accurate when viewed on an LCD.

The first one looks the closest and the last isn't too bad either.

For some reason I can't upload them (there really isn't much to see anyway).

Scanrez1_Althor.png
Scanrez2_Althor.png
Shadowmask_Twisty.png

These come with mame32 in the artwork folder.
Ginsu Victim:
I recommend Ummon's idea of rotating Scanrez2_Althor. It looks MUCH better.
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