afk.ai/Auto-rig/Spiders and insects
Auto-rig a spider, insect or crab with AI
Eight legs is a lot of bones to place by hand. afk.ai finds every leg for you, fits an eight-legged skeleton with fangs and an abdomen, and plays a walk cycle where the legs move in the right order.
Before is the sample model as it's uploaded: a mesh with no bones. After is the same spider on afk.ai's skeleton, playing its animations.
How it works
- 1
Upload
Drop in your spider as a GLB, a self-contained glTF or an FBX. Sign in with Google; it's free.
- 2
The AI finds its body
An AI reads the mesh and works out where everything is. On a good graphics card it runs right in your browser; otherwise the cloud rigger does it.
- 3
Skeleton and skin
afk.ai fits its spider skeleton to what the AI found and weights the skin, so the mesh bends at the joints.
- 4
Animate and export
Preview every animation on your model, then download one GLB with the skeleton, skin weights and all of the animations.
What the spider rig includes
Spiders, crabs and insects: eight jointed legs, fangs and an abdomen.
Skeleton: 56 joints
- Hips, a two-bone body and the head
- Two fangs
- Eight legs, each with three segments and a tip
- A three-bone abdomen
9 animations
Attack, Bite, Death, Death 2, Eating, Hit, Idle, Jump, Walk.
Download the rigged spider (.glb, 0.6 MB)The sample above with its skeleton and all 9 animations. CC0: use it for anything.
Models that rig best
- Legs spread out around the body, not tucked underneath, fit best.
- When afk.ai asks what it is, pick Spider or insect, for crabs too.
- One creature per file.
Use your rigged spider in Unity, Unreal, Godot or Blender
Unity 6
- Open Window > Package Manager, click +, choose Add package by name and enter com.unity.cloud.gltfast (glTFast).
- Drag the .glb into Assets. It becomes a prefab with the mesh, skeleton and one Animation Clip per animation.
- Create an Animator Controller, drag the clips into it and assign it to the Animator on the prefab.
- Prefer FBX? Export one from Blender, then in Unity set Rig > Animation Type to Generic (creatures aren't Humanoid avatars) and click Apply.
Unreal Engine 5
- Drag the .glb into the Content Browser (or +Add > Import). Unreal 5.1 and later import glTF natively.
- Click Import in the options dialog. You get a Skeletal Mesh, its Skeleton, a Physics Asset and one Animation Sequence per animation.
- Creatures keep their own skeleton, so there's nothing to retarget to the mannequin.
Godot 4
- Copy the .glb into your project folder. Godot imports it as a scene with a Skeleton3D and an AnimationPlayer holding every animation.
- For cycles like walks and idles, double-click the .glb, select the animation, set Loop Mode to Linear and click Reimport.
- Instance the scene and play one: $AnimationPlayer.play("Walk").
Blender
- File > Import > glTF 2.0 (.glb/.gltf), and pick the file.
- The mesh comes in on its armature, with the first animation active: scrub the timeline to play it.
- The other animations are on NLA tracks named after them. Click a track's star (Solo) to play it.
Questions
›Does it work for insects with six legs, or crabs?
afk.ai uses the spider skeleton for spiders, crabs and insects. It has eight legs, so it fits spiders most closely.
›What animations come with it?
Walk, Idle, Attack, Bite, Jump, Eating, Hit and two deaths. All of them are in the download.
›Can I use it in a commercial game?
Yes. Your model stays yours and the animations are CC0.
›Is afk.ai free?
Yes. Rigging, the animations and the GLB export are free. You sign in with Google, and the site is supported by ads.
›What do I need to run it?
A computer with Chrome or Edge. With a decent graphics card the AI runs in your browser (the first rig downloads the 1.1 GB AI model once). On phones and weaker computers, afk.ai offers its cloud rigger instead.