Animating Characters Whose Parts Will Need to Move Independtly

[OathkeeperX13]

I'm making a character whose top and bottom need to move independently once they're in game. The top moves to aim and shoot while the bottom runs in whatever direction the player wants. I'm going to be importing into Gamemaker and I'm new to Spriter.  Is it possible to have both parts in the same project or would I need to do separate ones? I'm just an artist, so I really have no idea.  I just want to have everything exported in a correct and efficient way for a buddy who offered to help program.

[Mike at BrashMonkey]

Hi, I think I answered you on youtube. I'll paste my response here:
There are a few potential solutions depending on which authoring system you're using and what level of Spriter support it has.

\If you'll just be exporting your animations as sprite sheets and using them as normal sprites, then just have the upper body a separate sprite pinned to the lower body at the waist. If you're using actual Spriter play-back in game with a Spriter API, then you might have two options. IMPORTANT! No matter what method you attempt, use place-holder art FIRST, spending as little time as possible on the animations so that it's not a major loss of time if you can't get it working and need to re-create your character using a different method.

 

Also, IMPORTANT: no matter which method you use, you'd also want an action point as a child of the bone the gun is attached to, always aiming the same direction as you want the bulettes to fly.

 

1) You might be able to programmatically hijack specific bones and set their angles to aim at a target or in a specific direction. (this is tricky/complicated and can only be done with the most fully featured Spriter API's such as for Construct2 or with SpriterdotNet or SpriterDotNet for Unity)

2) I personally would have the upper and lower bodies as separate Spriter objects, with an "action point" at the top of the waist of the lower body entity for use to pin the upper body Spriter object to it. I'd then create an upper body aiming animation that is exactly 360 milliseconds long and covers the full range of aiming angles that the character can shoot at, smoothly tweened from one to the other, with as many key frames in it as are needed to make the full tweening from any angle to any other angle look good. I'd then always/every tick=pin the upper body to the lower body, and set the timing of the upper body animation to match the required angle. (tricky math goes here... you'll likely need to experiment a bit)