Part II: Shading
In part one we discussed light casting and gradients, in this one I want to go over advanced shading. Shading consists of three basic things midtones, highlights, and shadows. Midtones can be thought of as your base color value; a highlight is any value that is higher in brightness than the base color; shadows are any value lower in brightness.
This is similar to the light casting examples on the primitives; the light being casted creates a highlight and a shadow. The concept is a pretty simple one that you already understand; anything that is raised on a surface will cast a shadow.
There are 2 ways of getting shadow and highlight values, one method uses the color mixer, the other is layer modes. I use the program GIMP for most of my artwork; it is free and contains some really powerful tools that rival and sometimes surpasses photoshop. You can get GIMP here (
https://www.gimp.org/)
Color mix method:
The color mix method works like this; you open your color mixer in gimp by clicking on your color swatch in the tool tray it looks like this.
A window will open like this:
This is the color mixer; it contains 6 options for altering colors: Hue, Saturation, Brightness value, Red, Green, and Blue. What we are interested in for the moment is the Brightness value it is the slider marked on this panel by
V. This slider works in percentage so 0% is pure black, 100% would be pure white; very simple.
The mixer works the same way with any color that you add, if you are working with a default red, green, or blue as a base you may need to saturate the color in order to get highlights. You can do this very easily by adjusting the slider marked
S.
Layer mode method:
The layer mode method is a little more complex though it does have advantages over the color mixer method. This is the method that I used throughout classes and is still my preferred method of shading. To start off you will need 2 layers that you should rename to highlight and shadow.
Starting with your highlight layer look over to your layers panel, at the top of this panel you should see the layer mode which says “normal” we want to set this to the mode “screen”
for your shadows layer you will want to set the mode to “multiply”, these modes use grayscale values to apply brightness to the layer below it, regardless of color or brightness value present. Pure black on the highlight layer results in the image not changing what so ever, as you increase the white value the area becomes brighter, conversely white added to the shadow channel results in no change, the darker gray makes the area darker.
There are different ways to use this technique: one way is to use the color mixer to select your value by using the brightness value slider; alternatively you can use my preferred method, and that is to use the brushes opacity to set your value.
By setting your color to pure black or white, and setting the opacity to 10% you have essentially the same thing as using 10% brightness. If you mess up you can simply swap your color to shift from light and to dark and vice versa.
Let’s start applying some of the techniques we have learned so far, I’ll start by creating myself a new document with an alpha channel, I’ll add my highlight and shadow layers and set my modes. I want to create a simple rock object, I need to select a base color and I want my rock to look as if it was made from granite so I will start with a base color of 50% gray. I’ll just grab a random brush out of the brush palette and draw a blob on the screen without much concern for the shape of it.
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So I’ve got this kind of shape, it’s not perfect but it doesn’t matter at all, at this point I want to determine where my light source is going to be and start drawing in my major shadows, I know that my light source is top and to the left so that means my right side will be quite dark, I bust open the color mixer and change my brightness value to 40% and literally scribble on a shadow to the right.
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I did not spend any time counting pixels or concern myself at all with the shape of this, I took my pencil tool and just scribbled, afterward I went back to fix the lines and make them a little nicer. So, I have my right side shadow I need my front side to finish defining the shape of my rock. I’ll open up my color mixer again and set my brightness to 45% and scribble out the front shadow.
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Neato, it’s starting to look like something; at this time I’m gonna switch to my shadows layer and start adding details using my preferred technique. So, I am swapping my colors for black and white, I set my opacity on my brush to 10% and start working on my shadows layer with black selected.
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I’ve placed my shadows, I have a super-secret technique for doing this: I just scribble, I literally scribbled this entire rock so far.. This isn’t hard, Time to add the highlights.
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Highlights are in, I took this time to play around with my values a little bit, I did all this by just using those two layers and my pencil tool opacity set from 5% to 10%. Now I admit this isn’t my best work ever but it isn’t my worst either.
Let’s do a human sprite shall we? I’ll strip out the base character from SS13.
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Now, I have some anatomy issues with this character: the head shape is bad and he does not have shoulders; I’m going to correct the shoulders and not concern myself too much about the head shape at the moment.
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That’s better, I need a base color for our character; I’m going to bang one out in the color mixer really quick. Tutorials on how to use the color mixer including palette selection will come in future lessons.
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I’m happy with this color, I now I need to create my highlight and shadow layers, and just like for the rock I want to figure out the basic shapes by applying lighting first.
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I’ve got my base shading down; I want to further this by creating muscle definition using the same techniques I did for the rock.
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Here’s what I’ve come up with after about 10 minutes of work, not too shabby.
That’s about it for this installment; I encourage you to play around with highlights and shadows to see what kind of results you can get. In the next one we will start to explore the color mixer more in depth.