AuthorTopic: --- Expanding the C64 palette to 32 colors ---  (Read 16906 times)

Offline Mathias

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--- Expanding the C64 palette to 32 colors ---

on: July 05, 2011, 01:12:52 am
Currently engaged in a game project. All graphics use only the Commodore 64 palette. After already completing quite a bit of art, the game is now changing significantly.

As a result I feel the C64 pal is now inadequate for what I want to do with the game's art, since a slightly different art direction is being chosen. So I set out to "update" it.

Unfortunately, I assumed I could remap the palette easily and quickly with new/better colors, while not manually re-pixelling any existing art. But no. This was a naive notion on my part. Afterall, the C64 palette is a good generic 16 color palette. Not easily thwarted.

-- View a quick test --

So, that was a failure. Learned, and moved on.

___


Rather than alter the existing pal, I'm just going to add to it, round it more. That way the existing art can stay and not require updating, and at the same time I can create new game art with the new colors.

Sven suggested I not exceed 32 colors for the new expanded C64 pal. I agreed.

So, the idea is to add 16 more colors. I suck at palette creation. Never tried it before actually. With so many great palettes readily available I haven't had the need until now.

___


Let's get started.

The rest of this post is pretty much images, since this is an inherently visual/graphical issue, I figure why not. I hope the following images are decipherable. They convey my C64 pal editing progression.

Notice, the first thing I do is investigate the existing C64 pal's underlying luminosity values.







Disappointing, but this is as far as I've gotten. I'm hoping for some insights from you Pixelatians.

I get the haunting feeling I should have more midtones and less darks and lights. As of right now, my luminosity range is pretty much an even gradient from black to white, with a little bias towards shadows (mainly because I've always wanted more darks in the C64 pal).




Thoughts?

Offline ptoing

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #1 on: July 05, 2011, 02:07:23 am
I see you have somewhat averaged the closeness of the light blue/grey and light red/green lumapairs. Those are very close on the real thing, almost so close that they can be used for almost invisible PAL blending with each other.

Also, the nice thing about the lumapairs on the real thing is that you can get new colours by arranging them in lines. Like alternating likes of blue/brown/blue and so on will yield a new colour, and you acutally get a different one if the first colour is brown (depends on which colour is on odd or even lines I think). So you can actually get 14 new clean colours like this and with the mixing of the 2 close pairs a bit more (not as clean).

This effect tho you can not do see on a PC monitor (apart from some emulators and there not quite perfect yet), it has to do with how the PAL signal works.
So perhaps you should make a call on which colour you want darker in each pair, and give up on the lumapairs, which are only good for really really subtle tinting, and to be honest I do not see any subtle tints in your stuff to begin with, everything is very poppy and bright. Maybe worth a try.
There are no ugly colours, only ugly combinations of colours.

Offline Mathias

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #2 on: July 05, 2011, 04:08:43 am
So, you're basically saying that the lumapairs is pointless on a PC?

One reason I like the lumapairs is that it simplifies using the palette - when you're shading something you only worry about 16 shades, with my new palette. If each color was a different luminosity, you'd have 32 shades to worry about. Not a bad thing, though . . .

I dunno. Seems like a major decision I better make right now, before going further. Can't decide . . .

Offline HughSpectrum

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #3 on: July 05, 2011, 09:22:51 am
I'd probably recommend, especially for your darks, to use teal and a dark gold at the very least.  I find that these colors do a good job of having a similar effect to greyscale where they act as buffers to many other colors, which should make them useful for shading.  A bluish-purple should work too for shadows and the like (since it's also an intermediate color).

Not sure about the light colors.  Maybe a tan (which would make be useful for skin and buffering alike), but I don't work with light colors often enough to really know what should be there.

Offline Helm

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #4 on: July 05, 2011, 10:49:16 am
Α global palette over 16 colors is counter-intuitive. What you're doing imo doesn't achieve a step up from the original palette, regardess of the interesting SCIENCE! behind it. Just take the plunge and either work with 8-bit limitations or not. Middle-steps do not achieve an esthetic end, and you can't improve 8-bit artwork just by throwing more colors at it, you'll have to repixel it.

Offline Mathias

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #5 on: July 05, 2011, 11:28:56 am
I'll keep that in mind, Kitten. Thanks.


Α global palette over 16 colors is counter-intuitive. What you're doing imo doesn't achieve a step up from the original palette, regardess of the interesting SCIENCE! behind it. Just take the plunge and either work with 8-bit limitations or not. Middle-steps do not achieve an esthetic end, and you can't improve 8-bit artwork just by throwing more colors at it, you'll have to repixel it.

True, part of why I'm doing this is the interesting science behind it. But, I'm not really trying to improve the C64 palette; once out of the 16 color realm we enter a different "bracket".
Working with 8-bit limitations was never my intention. Originally, deciding to use the C64 pal was meant to capture some automatic nostalgia, but is now a detriment.

Agreed; adding more colors doesn't improve/fix, therefore ALL game art objects will not have more than 16 colors. Imposing this restriction disallows me to repixel the large story screen images (such as the one used in the "tests"), since they all already have the original 16 colors, and preserve the general "graphical depth" of all new game art assets.

This initiative to expand the C64 pal may or may not be particularly useful to others, but for me, it at least solves a specific problem and will allow me to move forward with my game art creation.

__

Right now, I'm trying to decide:

1) Whether I'm ditching lumapairs.
2) If I should focus on more midtones instead of shadows. The orig C64 pal is mainly midtones. My underlying luminosity ramp may need weighting towards the middle-range.
3) Add in more grey colors like orig pal?

Offline yrizoud

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #6 on: July 05, 2011, 01:21:51 pm
You may want to try DawnBringer's perceptual lightness, to see if it shows different "gaps" where an extra color with a unique lightness would fit.
Quote
sqr[(0.26*r)^2, (0.55*g)^2, (0.19*b)^2] , multiplying with 1.56905 normalizes to a scale of 0-255

RGB is notably a bad space to work in, things that are mathematically "pretty" (even statistical distribution, linear interpolation) will not produce the best visual result.

Offline Mathias

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #7 on: July 05, 2011, 02:53:36 pm
what

Offline ptoing

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #8 on: July 05, 2011, 04:13:31 pm
you can do it in google with this (if i understood him right)

Code: [Select]
(sqrt((0.26 * R)^2 + (0.55 * G)^2 + (0.19 * B))) * 1.56905
Where the result would be a number which you enter for all 3 values to get a straight grey.

I just tried it with one of the c64 colours and it is the same result as going greyscale in Promotion.
Which might have been a fluke. Just tried another colour and it did not produce the same grey as it does in PM (and as is the proper luma value)
« Last Edit: July 05, 2011, 04:16:10 pm by ptoing »
There are no ugly colours, only ugly combinations of colours.

Offline Mathias

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Re: --- Expanding the C64 palette to 32 colors ---

Reply #9 on: July 05, 2011, 05:27:46 pm
Crap that reminds me, I'm applying luminosities to each color with  . . . PHOTOSHOP.

Will have to proof PS's output against PM's and make necessary adjustments. OR I can figure out PM's palette gizmos and work exclusively in PM for all this. (but I doubt it)
OR OR
sven can do it all for me!