AuthorTopic: Pixel school  (Read 45699 times)

Offline Negative Gravity

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Re: Pixel school

Reply #50 on: August 06, 2005, 04:46:38 am
I don't think it is Fredde.  8)

Here is my almost finished piece.
I don't see anything else that could be done with it but if anybody sees anything be sure to slap a post up here.  ::)


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Offline crab2selout.png

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Re: Pixel school

Reply #51 on: August 06, 2005, 08:19:47 pm
I have a question about night time colours, Lief. At nighttime, the only light we're getting(aside from manmade stuff like lightbulbs) is sunlight reflected off of the moon. So, because when light bounces off an object, it becomes tinted by that object, does that mean that hightlights during nightime should max out at an offwhite grey colour like the moon?

And you mentioned many, many posts ago in a reply to a topic, that shadows tend to move towards the opposite colour of the light(blue light means yellow shadows). If the blue light is tinted to red or something after bouncing off an object, will the shadows still be yellow, because of how the light originally was, or will they become green?

Offline Helm

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Re: Pixel school

Reply #52 on: August 06, 2005, 08:36:01 pm
Shadows don't have a colour. It's just the eye mechanism compensating for equillibrium. The complementary shadow colour of any lightsource is the opposite one in the colour wheel. Keep in mind the impressionist yellow banana with purple shadow.

There is no 'white' or 'gray' light in nature. The closest you can get to it is with harsh flourescent lightning, which makes things look very clinical and sterile. Ugh. Light, as it reflects on the moon as you say, passes various enviromental filters to get here, and without getting too technical (not because I don't want to, but because I don't know the actual effects), isn't gray not white, but a shade of, you guessed it, desaturated deep blue.

Offline ptoing

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Re: Pixel school

Reply #53 on: August 06, 2005, 09:10:59 pm
On a sidenote about shadows and their saturation:

On skin the shadows are actually more saturated than the highlights which is due to the fact that skin is not a surface but consistsof multiple layers. Also light gets reflected under the skin and causes subsurface scattering and such. Rather complicated in fact. Just wanted to point out that shadows not always have lower saturation than lights.

ta
There are no ugly colours, only ugly combinations of colours.

Offline Negative Gravity

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Re: Pixel school

Reply #54 on: August 06, 2005, 09:18:00 pm
Whoa!  :o
I sure learned a lot. I didn't even expect there's so much stuff to just one aspect of a daily thing that you see all around (I'm talking about shadows) I'm taking notes... inside my head.  :)

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Offline BeL

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Re: Pixel school

Reply #55 on: August 06, 2005, 09:34:30 pm
yeah shadows are very interesting!
btw no1: are all these going into the wiki? cause it would be a waste to re write them.
btw no2: where the greasy is our teacher?
btw no3: yes, pixeling poo can be very interesting ::)

Offline Negative Gravity

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Re: Pixel school

Reply #56 on: August 06, 2005, 10:20:23 pm
Didn't you see his post? He went somewhere for the weekend :P School's out for now :)

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Re: Pixel school

Reply #57 on: August 06, 2005, 11:14:31 pm
Quote
Shadows don't have a colour. It's just the eye mechanism compensating for equillibrium. The complementary shadow colour of any lightsource is the opposite one in the colour wheel. Keep in mind the impressionist yellow banana with purple shadow.
No colour? well, shit, that complicates this just a bit.  :-\

While I'm thinking on this and looking up on this subsurface scattering stuff, here's another question that this has come to mind. I figure that I'll work on recolouring an older piece to practice this light stuff. The part that's confusing me when doing this though, is what happens to the colour of an object when the light isn't yellow. I know a banana is yellow when the light is yellow, but what happens to the yellow(of the banana) when the light becomes blue?

And since I probably haven't made myself clear enough. In yellow light, the colours I would use for colouring that banana would be "-whitish yellow-yellow-orange-purple". So how does it work with blue light? Something like "whitish blue-blue-purple-yellow"?

Er, and if you don't mind another question, I remember from science that light that is the same colour as an object gets reflected and the rest absorbed(I hope that's how it goes), which is why solar panels are black so they absorb light, and you wear white in the summer to reflect it, etc. etc. But what effect does that have on an objects colour? If a blueberry and a banana are sitting outside at night, what effect will the deep saturated blue light have on the blueberry compared to the banana? And how about during the day?

Thanks again for the reply, Helm. Any access to the wonderful knowledge in that big ol' brain of yours is much appreciated.

Offline Helm

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Re: Pixel school

Reply #58 on: August 07, 2005, 09:43:14 am
actually I am by far not the right person to get so technical about light. I have a few basic ideas from colour theory class, which refer to art theory, not the physical manifestation of light, and the rest is 'what-looks-good'.

However let's make a few reasonable - if possibly false - assumptions, here:

let's say that a surface, whereas has no colour of it's "own", meaning that without light to hit it, there's no hue there, when light DOES hit it, the particulars of the surface bias the hue towards a specific part of the spectrum for whatever reason. To not get into an epistemological discussion - this is just as good as saying that a surface 'tends' to be blue or 'tends' to be yellow. A banana let's say then, will be yellow when light hits it. If that light is also yellow, awesome. If it's not yellow, the banana's colour will be the colour of the light mixed with yellow. I think this is pretty much correct.

As to shadows, they indeed have no colour. As shadows don't exist themselves. Again this goes into epistemology and how we choose to define things, but a shadow occurs where something blocks out the light in a scene. It's not an individual physical entity.  However, as we said above, a surface has it's own 'colour' and a shadow is almost never pure black to mask it. So a shadowed surface should still have a tint and some saturation, depending on what type of surface it is, how it reflects ambient light etc etc.

as to 'okay in yellow, how about in blue?' question. First of all, let's mention that the sun's yellow light isn't eggyyolk yellow or anything. In rgb terms, it's something like 250,255,255. Yellow is the warmest colour on the palette anyway, so just a little tint like that does colour things strongly. So if you wanted to make something with an equally gentle tint, but only of other hue, like blue you wouldn't go nighttime nocturnal, but just 5-10 rgb points in that direction. In that case again, I theorize that the shadow tints will just be shifted in the same direction equally. The 'tinting' effect is a peculiarity of the eye, not a natural physical phenomenon. The try tries to balance out the type of colours that hit it, it's not that shadows like to turn blue or anything.

Again, these are mostly rationalizations. Maybe someone will come into this thread like goat or lief and give us actual physiological explanations for all of this.

Offline mjau

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Re: Pixel school

Reply #59 on: August 07, 2005, 06:22:25 pm
A banana let's say then, will be yellow when light hits it. If that light is also yellow, awesome. If it's not yellow, the banana's colour will be the colour of the light mixed with yellow. I think this is pretty much correct.
Sorry, but that's pretty much wrong, actually.  For example, if a pure yellow object (meaning no "blue wavelengths") gets hit by pure blue light (only blue wavelengths) and nothing else, the object will appear black.  This is because all the blue light (or more correctly, all the wavelengths of the blue light) was absorbed by the yellow object, so there's nothing left to reflect. If a pure yellow object gets hit by a pure purple light in stead, the object will appear red, because the blue wavelengths got absorbed, but the red ones got reflected.

The effect is pretty much like what you get if you create two layers in an image editor, draw the object in the bottom layer and the color of the light in the top layer, and then set the top layer combine mode to multiply.