Photoshop is a very powerful tool. When used correctly, it is an integral component of any games designer’s toolbox.
We had a Creative Futures session dedicated to “Photoshop Basics”. Here are a few of these detailed further (Please note that all screenshots are taken with Photoshop CS 6).
Resolutions, File Sizes and the Set Up of New Files
When dealing with the resolutions of images, it is best to stick to the following guidelines:
72 DPI images tend to be fairly small in file size, which makes them great for the internet. However, once these images are printed, they tend to not look very good due to their low quality.
150 DPI for Web & Print
150 DPI images are a middle ground for images that have to be both printed and made available on the web. These are slightly larger in file size and will not load as fast as a 72 DPI image, but some quality will be preserved.
300 DPI for Print
300 DPI images are of a high quality, which make them perfect for print. However, these images are much larger in file size. This would increase the time it would take to load them on the internet. As such, we would only use 300 DPI for images that only have to be printed.
Raster (File Type)
Raster images (also known as bitmaps) are made up of pixels that each represent an individual colour. This makes them good for working on photographs (editing, for example) and photo-realistic images, as you are directly manipulating pixels. However, image quality will degrade after excessive re-sizing.
Vector (File Type)
Vector images, rather than being made up of pixels as bitmaps, are made up of mathematical projections which allows the software in use to calculate the scale of shapes being drawn. Most importantly, this allows for unlimited res-sizing of the images that are drawn.
When creating new files, it is important to pick the most suitable file type and resolution for the task at hand. For example, to bring this back to Games Design, you could use Vector to create logos and you could use Raster to create sprites for a 2D game that would be at a fixed size.
Layers in Photoshop work much in the same way as placing acetates on top of other acetates to combine different elements of an image into one. See the image below which illustrates this.
As you can see, the background layer is plain white. On top of the background layer, there are three layers. Each of these layers has a shape and they have both been placed on top of each other. Any changes to each layer will apply only to the layer that is selected. So, this means that if I was to make changes to the selected layer in the example above, the changes would only apply to the Polygon layer.
Layers can also be flattened/merged to combine all the layers into one.
There are a multitude of selection tools within Photoshop. Two of the most widely used are the Marquee Tool and the Lasso Tool.
The marquee tool is a non-standard geometric selection tool which can be used to select areas within a rectangle, much like in the below example.
The lasso tool works in much the same way, except it allows selection by means of drawing around the area you wish to select. This allows you to select things of a much stranger shape. You can see this in the below example.
The clone tool is a very powerful tool. It allows you to select an area on an image and copy it elsewhere. It works pretty much like a stamp and can be used to correct errors as a result of copying and pasting parts of an image or to even clone out blemishes in a picture.
The dodge and burn tools are used exactly like their real life counterparts. They assist with the lightening and darkening of images at certain spots.
Transformations (Edit > Transform)
This setting allows you to change a shape’s size and orientation, as well as distort shapes to make other shapes.
Adjustments (Image > Adjustments)
Curves are used to change colours on the fly. An example of this option can be seen in the image below.
You use this tool by manipulating the line on the grid, thus, creating a curve. Dragging the curve towards the white side will add more white to the image, whereas dragging the curve towards the black side will add more black to the image.
The brightness/contrast sliders alter brightness and contrast as you would expect. Photoshop also has the ability to preview the changes made with this setting before applying the changes.
The hue/saturation controls also alters the hue and saturation of the colours in the image as you would expect. Again, Photoshop has the ability to preview any changes made with this setting before they are applied.