Spritesheets v Atlases

[jonbon]

Hi,

 

Im wondering what the difference is between Spritesheets and Atlases?

 

I know that Spritesheets have to have a fixed frame size but in the context of creating an animated sprite, you could achieve this with either a Spritesheet and an Atlas.

 

Is the advantage of a Spritesheet that you don't have to name all the frames which could get tedious with large animations?

 

Thanks

[Ezelia]

when you animate using spritesheet you need to draw every animation frame and redraw the whole character each frame.
when using Atlas you only draw each element once and compose them with rotations/scaling/animating to create every animtion without redrawing the whole frame.
 

There are some software to help you create animations with atlases : http://dragonbones.github.io/demo.html http://esotericsoftware.com/  http://www.brashmonkey.com/index.htm

 

[feiss]

I don't completely agree with Ezelia. You can perfectly use an Atlas for storing the animation of the full body of one character, why not? it's not just for body parts, there's no technical restriction or difference in that sense.. (of course, the use of an Atlas is compulsory if you have the animation in parts, but that not excludes it for a full body anim)

 

I don't think there are more differences than those jonbon said, I think it's more a matter of your organization and pipeline, and your preferences..

[rich]

There is no technical advantage of using a sprite sheet at all. They tend to use more space both in memory and bandwidth because they don't pack frame data as efficiently as a texture atlas does.

 

However, there are lots of legacy graphics out there in that format, and its still quite popular today. So we support them. But you should try and pack graphics into atlases where possible to save on ram.

[jonbon]

Got it. Thanks for clarifying guys!

[Chris]

when using Atlas you only draw each element once and compose them with rotations/scaling/animating to create every animtion without redrawing the whole frame.

 

Sorry, thats not true. You can perfectly do that with a sprite sheet as well.

 

The only difference between sprite atlas and sprite sheet is that in a sprite sheet, all sprites need to have the same dimension and are addressed by a index number (from which x/y/w/h in the sheet is calculated), where in a sprite atlas, you can combine sprites of all possible sizes that are addressed by x/y/w/h coordinates. A sprite atlas doesn't even force you to name/key all your sprites - an array with coordinates and dimensions does the same job very well.

[Ezelia]

what I wanted to say is that, frame by frame animation when you redraw the whole frame is easier with spritesheet than atlas (you dont have to deal with specific coordinates of each frame).

on the other side, skeleton animations are better with Atlases since you are not forced to use a specific dimension for all body parts.

you are always able to use both of the technics with spritesheet or Atlas but depending on the animation technique you use, one is more suited than other.