General questions and research.
1.What is a game character sprite sheet?
Okay, first let us look at what is a sprite. a sprite is a rectangular image with a certain width and height in pixels, for instance, 140px x 140px for each pixel. For each pixel, a amount of memory is used to save its colour depth, which is by default 32bit.
Depending on your graphics hardware you can only use certain sizes, so sometimes your sprite must be filled with unused pixels to match hardware constraints. This can increase memory usage.
So if we use the wasted memory by packing more sprites into that space (empty), this is then referred to as a sprite sheet.
In conclusion, a game character sprite sheet must then consist of the different states of the character movements(run, walk, jump, idle, swim, climb, crouch etc.)
In the example below is the Character Rossi from the old arcade classic Metal Slug’s complete sprite sheet.
in some of the characters movement, we can see only the torso in its different states, this is due to the lower leg movements staying the same depending on if the character is walking or running while doing an action.
2.How many instances does a game object sprite sheet such as a hero character have?
I think this depends on the number of movements that your character can perform during the game. So for instance, if your character can move only up, down, left and right, walk, run and jump. you would have to build out those sprite sheets individually per movement or action your character performs.
3.Best Practices for creating a game object sprite sheet?
This has been made easy with some software (Adobe Animate CC 2017) that can after you created and animated your character, export those movements as sprite sheets with the necessary code that your gaming engine uses to read those file, already included. YAY! thank god for that!