Ayla sprite demo: overlap sprites for more colors

[Bregalad]

Simple demo I did very long ago (2004) which shows how to use 2 sprite layers on a NES to have sprites that looks like SNES, in this case, Ayla from Chrono Trigger.
No source.

[slobu]

Has anyone tried instead of overlapping sprites - a sprite and a flickering "mask" sprite for half-tone effects?

Wouldn't that give some of the benefits of 2 sprite layers but reduce unintentional flicker?

[snarfblam]

This sort of thing has been discussed pretty extensively before.

[slobu]

This sort of thing has been discussed pretty extensively before.

I don't see where they specifically mentioned half-tone by a black masking sprite. Can I infer that you mean that topic reached a unanimous opinion that flickering of any sort sucks?

[Sik]

Yeah, that was about alternating between two sprites to get more colors through the checkerboard pattern, but apparently that technique outright doesn't work properly at all due to how the NES generates the video signal (lots of color interference, and also the half-dot shenanigans).

I think slobu is talking about using a solid sprite that flickers. That isn't prone to those issues... but flickering is noticeable no matter how hard you try. A good example of this would be the shield in Sonic 2, it's blatantly obvious it's flickering even at the speed it goes.

[Macbee]

Ayla is a classic, fantastic demo!

Almost everyone here on Nesdev seems to hate flickering - but I still think it's an amazing way to add more colors to NES graphics. I create new images using this technique everyday and my latest tests have less noticeable flickering.
I guess flickering results can be very good or disastrous - it all depends on how it's done.

"All unanimity is stupid" - Nelson Rodrigues

[Bregalad]

I just tried it on my PowerPak with my old CRT TV, and you can very clearly see it's flickering.

flickering of any sort sucks?

I'd say flickering is good if you want something that flickers.
If you're like "WOW I WILL FLICKER AND GET MORE COLOURS" then you're wrong, it'll just flicker.

[tepples]

The Felicia pic doesn't flicker on this Sharp CRT any more than interlaced graphics on a Dreamcast or newer console flickers.

[Macbee]

I just tried it on my PowerPak with my old CRT TV, and you can very clearly see it's flickering.

I never said that flickering isn't unnoticeable. I said it's less noticeable on my recent tests.

I'd say flickering is good if you want something that flickers.
If you're like "WOW I WILL FLICKER AND GET MORE COLOURS" then you're wrong, it'll just flicker.

Who are you to tell I'm wrong? I have my opinion and you have yours. Keep overlapping your sprites and I'll keep flickering mines.
This message board is a place to share tests and experiences - but it's hard to do it when people doesn't seem to respect different ideas.

[lidnariq]

When I visited Europe before the lead-in-CRTs ban, I could see an obnoxious flicker on standard 288i OTA broadcast. At 50Hz.

Whether or not flicker is visible basically depends on the refresh rate, ambient lighting levels, and whether the average luminosity changes too much. (example: bits of the UI in Chrono Cross have single scanline high high-contrast elements. I can see them flicker at 30Hz, stupid interlaced video modes) HOWEVER "average luminosity" is something that's spread in space as well, hence checkerboard interleaving being better. Saying that it's never appropriate is blatantly untrue. (When we discussed this last time, Sik mentioned that he uses it everywhere in ProjectMD. And it looks good.)

[Bregalad]

It's true the flickering is less noticeable if the colours are close together. But in that case you could also use dithering, and the result to the eye would be comparable, but without the flickering.

And sorry but it's not a matter of opinion - it just flickers, this is a technical fact, not "just my opinion".
Now you are right that my opinion is that it's not a good idea to do this in a game, and yes this is my opinion - Sunsoft had a different opinion when they did the intro of Batman.

And yes, some PS1 and PS2 games which used interlacing used to look very flickery, at 50Hz this can be very noticeable. This is a great reason why I use my more modern LCD TV.

[Sik]

Flickering is still noticeable because the human eye can distinguish each frame at 60FPS without much trouble =P

(When we discussed this last time, Sik mentioned that he uses it everywhere in ProjectMD. And it looks good.)

There's a difference though, here we're discussing about flickering between two solid blocks of color, while what Project MD does is alternate between two checkerboard patterns (which is a lot less noticeable since the areas are tiny and you're always seeing both colors at the same time). Moreover, it only looks right when the colors are close, in the few areas where Project MD uses this for translucency instead of gradients it's a lot more noticeable (although the monitor refresh rate not matching the emulated game probably isn't helping...).

Also it looks right on the Mega Drive because it doesn't do anything weird with the pixels, the NES has the whole half dot shifting issue that apparently interferes a lot with the effect (not to mention that colors are usually much further apart).

It's true the flickering is less noticeable if the colours are close together. But in that case you could also use dithering, and the result to the eye would be comparable, but without the flickering.

Dithering also destroys the silhouettes of the shades in question. That's why I decided to take the checkerboard flicker approach in Project MD.

[Macbee]

It's true the flickering is less noticeable if the colours are close together. But in that case you could also use dithering, and the result to the eye would be comparable, but without the flickering.

I have no interest on dithered images. Dithering creates weird diagonal lines on CRT displays like this:



You can see this even on this official Solstice video: http://youtu.be/894_PNqBkx4?t=26s
I also given up on flickering of checkerboard dithered images for the same reason. Flicker using horizontal lines is still less ugly (on CRT TVs) than dithering IMHO.

[Sik]

Horizontal lines are a tad more noticeable than checkerboard patterns though. Again, I assume this is an issue specific to how the NES generates the video signal? Because I never had any issues with flickering between two checkerboard patterns regardless of what kind of screen was displaying it (heck, it actually blends better with a CRT TV in my experience).

[TmEE]

NES shifts pixels every line and it makes all diagonal lines ani edges look weird.