If you're trying to figure out how to write a roblox custom animation filter script, you've probably realized that the default animation system can sometimes be a bit of a pain to manage. It's one thing to make a character walk or jump, but it's a whole other ballgame when you want specific animations to take priority or stop others from overlapping in weird, glitchy ways. We've all seen those characters whose arms are flailing in a combat move while their legs are doing a casual stroll—it looks messy and breaks the immersion of your game.
The good news is that setting up a filter isn't as scary as it sounds. You're essentially just building a "traffic controller" for your character's movements. Instead of letting every animation fire off whenever it wants, you're telling the game, "Hey, if the player is swinging a sword, don't let the 'wave' emote play at the same time."
Why you actually need a filter script
You might be thinking, Can't I just set the animation priority and call it a day? Well, sure, you can try that, but Roblox's built-in priority system (Core, Idle, Movement, Action) only goes so far. Sometimes you have multiple "Action" priority animations that need to be sorted out. If you're building a complex RPG or a high-intensity fighting game, you need more granular control.
A custom filter script lets you create "tags" or categories for your animations. It gives you the power to say that certain animations are "interruptible" while others are "locked." For example, if a player gets hit and goes into a "stagger" animation, you probably want to filter out any input-driven animations until that stagger is finished. Without a script to handle this logic, your game is going to feel clunky and unresponsive.
Setting up the foundation
Before you dive into the code, you need to think about where this script is going to live. Usually, for a roblox custom animation filter script, you're looking at a LocalScript inside StarterCharacterScripts. Why? Because you want the character's animations to be handled on their own machine to keep things feeling snappy. If you try to run all of this through the server, there's going to be a tiny bit of lag that makes the character feel like they're moving through molasses.
The first thing your script needs to do is get a handle on the Humanoid and the Animator object. The Animator is where the real work happens. It's the object that actually loads and tracks what's playing. You'll also want to keep a table or a list of all the animations you plan on using, maybe categorized by their "type"—like Combat, Emote, or Utility.
The logic of the filter
The meat of your script is going to involve checking what's currently playing before you start something new. Roblox provides a handy function called GetPlayingAnimationTracks(). This is your best friend when building a filter.
Imagine your script like a gatekeeper. When a request comes in to play a "Heavy Attack" animation, your filter script should: 1. Loop through everything returned by GetPlayingAnimationTracks(). 2. Check the names or attributes of those tracks. 3. If it finds a track that shouldn't be playing at the same time (like a "Drinking Potion" animation), it calls :Stop() on that track. 4. Only then does it play the "Heavy Attack."
It sounds simple, but you have to be careful. If you stop everything, you'll accidentally stop the character's idle or walking animations, and they'll just slide across the floor like a mannequin. That's why the "filter" part is so important—you're specifically picking and choosing what to kill and what to keep.
Handling priorities properly
Even with a custom script, you should still utilize Roblox's internal priorities, but think of them as your broad strokes. Your script is the fine-tuning. One trick I like to use is assigning Attributes to the Animation objects themselves. You can add a string attribute called AnimationGroup and set it to something like "UpperBodyOnly" or "FullBody."
Then, in your script, you can just check: if track:GetAttribute("AnimationGroup") == "FullBody" then stopOthers(). This makes your life way easier because you don't have to hardcode every single animation ID into your script. You just tag them in the editor and let the script handle the rest.
Smoothing out the transitions
One thing that separates a mediocre game from a polished one is how animations blend. When your roblox custom animation filter script stops one animation to start another, don't just let it snap. That looks terrible.
The :Stop() and :Play() functions both take a fadeTime parameter. Use it! If you give it a value like 0.2, the animations will blend into each other smoothly. It makes the character feel more organic. If you're filtering out a walk cycle to start a sprint, a quick 0.1-second blend makes the transition feel physical rather than digital.
Dealing with the "Animation Weighted Blending Fix"
If you've been around Roblox for a while, you know they updated how animation blending works a year or two ago. This broke a lot of old-school filter scripts. The "Weighted Blending Fix" changed how multiple animations at the same priority level interact.
Nowadays, if you have two animations at the same priority, they'll blend based on their weight (usually 50/50 if you don't specify). This is exactly why a custom filter script is more relevant than ever. You can't just rely on the engine to "override" the old animation; you have to actively manage the weights or stop the tracks yourself to ensure the character doesn't look like they're having a glitchy seizure.
Performance considerations
You don't want your script running a massive loop every single frame. That's a one-way ticket to lag city. Instead, trigger your filter logic only when a new animation is requested. You can even wrap it in a custom module script so that your combat script, your emote script, and your movement script all call the same "PlayAnimationWithFilter" function.
This keeps your code "DRY" (Don't Repeat Yourself). If you ever want to change how the filtering works—maybe you decide that emotes can overlap with walking—you only have to change it in one spot instead of hunting through ten different scripts.
Testing and debugging
The hardest part of writing a roblox custom animation filter script is catching the edge cases. What happens if the player spam-clicks? What happens if they trigger an animation exactly as they die?
A good way to debug this is to print out the names of all playing tracks whenever a new one starts. If you see "Walk," "Run," and "Slash" all playing at the same time, you know your filter logic has a leak. Also, keep an eye on the IsPlaying property. Sometimes a track is "stopped" but hasn't fully faded out yet, which can cause weird behaviors if your script tries to restart it too quickly.
Final thoughts on customization
At the end of the day, the "perfect" filter script depends on your game's vibe. A fast-paced anime fighter needs a very aggressive filter that cuts animations instantly to keep the gameplay tight. A survival game or a roleplay game might want a much "softer" filter that allows for more overlapping and longer blend times.
Don't be afraid to experiment with things like AdjustWeight or AdjustSpeed inside your filter. Maybe instead of stopping a walk animation when the player reloads a gun, your script just lowers the weight of the walk animation's upper-body bones. This level of control is exactly why you're building a custom solution in the first place.
Once you get the hang of it, you'll realize that the roblox custom animation filter script is basically the brain of your character's visual identity. It takes a bit of trial and error to get the timing right, but seeing your character move smoothly without those awkward animation overlaps is totally worth the effort. Happy scripting!