How do 2D art assets (eg. sprites) work?

Question

I have an idea on a game and planning on developing a 2D game using XNA for Windows Phone 7.

I've started off today by free hand drawing some concept art of what I want some of the characters to looks like. Now the problem is taking those concepts and putting them in digital form.

The first thing I realized I really don't know the different parts of game art. I know there are sprites, textures and animation but that is about it. I think textures are sprites on a 3D object but not sure if that is correct? Here are some general questions about game art I have:

• Do you use textures in 2D games?
• Where do you apply the different parts of game art? For example when you use sprites vs animation.
• What are the difference between sprites, textures animation and other art?
• Are sprites, textures and animation the only art elements to a game?
• Is all 2D art in games considered sprites? Characters, background, etc.
• What size do you make your sprite sheets and each character in a sprite sheet?
• Any good books or tutorials on teaching to draw art from a digital prospective? I was thinking about getting "GIMP Bible", however most books like this teach more photo editing than digital drawing.

My objective is learn how to take my concept art(backgrounds and characters) and put them into digital form using Gimp and learning about the different parts of game art.

Anyway, thanks to anyone that can help.

Answer 1

I think textures are sprites on a 3D object but not sure if that is correct?

No.

Strictly speaking, a texture is a term for one or more images that are bundled together in an object called a "texture", within the context of a GPU-based rendering system. A texture can be used when rendering a 3D object. Or it can be used when rendering a 2D object, because 2D objects are just special cases of 3D objects.

A sprite is the term for an image, or part of an image, that is used to represent an entity (or part of an entity) in a game rendered with sprite/tile-based graphics.

You can put sprites inside textures. XNA does this internally, as it uses your 3D rendering system to render your stuff.

Do you use textures in 2D games?

XNA does. And generally most people who make games with 2D graphics do. It's the fastest way. But ultimately, this is an implementation detail that you should leave up to XNA.

Where do you apply the different parts of game art? For example when you use sprites vs animation.

This question is confused. Animations are composed of sprites. They're not separate things; one is a superset of the other. Typically you have a big image that holds multiple sprites that, when you flip between them, form animations.

What are the difference between sprites, textures animation and other art?

Again, this question is confused.

Is all 2D art in games considered sprites? Characters, background, etc.

Historically, "sprite" was used for things that move, while "tile" was used for things that don't move. However, you're using XNA, where "sprite" is used for both fixed and mobile things.

The historical reason was hardware-based. On 2D consoles, the hardware actually governed how sprites and tiles were rendered. It had hardware based tilemaps, scrolling, and sprite maps and animations. In modern graphics renderers, there's no need to make a distinction at the rendering level. Conceptually, you can make that distinction. But XNA makes you define your concepts.

What size do you make your sprite sheets and each character in a sprite sheet?

Within the hardware limitations for your platform of choice, however you see fit. That's up to you.

However, if performance is a concern (and in 2D games it often isn't a big one), you will want to pack as many sprites as possible into as few images as possible. You generally want all the terrain for your level in one sheet, and common enemies to share the same sheet. Things like that.

But you don't have to go crazy with it. The biggest thing is getting your terrain in a sheet. If you have to use different sheets for the at most 40 other characters you might be drawing on the screen, that's not going to be a major performance issue.