I am wondering how it is possible to preserve, say, a walking animation while also holding a tool. Would I have to animate the tool in the person’s arms as well as the entire body?
For example, how would I go about having a person hold a tool in a custom arm position rather than just the standard holding out your arm while still preserving the idle animation set in my game? Is there a specific way to go about this programmatically or does this belong in Art Design Support?
I haven’t managed to test this right now, but it all starts in the animation editor. You can use multiple animations at a time, as long as they don’t animate the same body part or other part. When in editor, create animation for, say, arm only, and leave the other body parts unchanged (don’t even add any keyframes). When applying multiple animations, their weight and priority become important. Roblox knows four priority levels (lowest to highest): core, idle, movement and action. Animation with higher priority level always overrides animation with lower one.
In your case, you have idle animation that has priority level set to idle, so your added animation (regarding arm only) should be set probably to action.
NOTE: these priorities are set in animation editor before exporting. I also mentioned animation weight, that has actually nothing to do with priority itself, but rather with deciding which animation is played if there are two or more with the same priority, all of them intended for the same part or group of parts.
I haven’t done it myself yet, but it should work if you are talking about R15 rig. R6 rig only has one arm part, while R15 arm consists of multiple parts.