How to Use AI-Made 3D Models in Roblox Studio

Get a Bake3D model under the limits

Bake3D models are much denser than 20,000 triangles. Our sample fox has 60,000. Our demo robot, T-rex and person, made at Standard quality, each have about 150,000. Even the cleaner option is over the limit: the Game-ready mesh option makes about 18,000 four-sided faces, which the file stores as about 34,000 triangles. So you will lower the count in Blender.

Here is what we did with our fox. It works for any Bake3D model.

1. Export from Bake3D. For an NPC, download the rigged GLB, or an animated GLB or FBX with one clip. Bake3D’s FBX holds one baked animation per file, which matches Roblox’s one-track rule. Set a height in metres at export if you want a real-world size.
2. Import it into Blender with File, Import, glTF 2.0 (or FBX).
3. Lower the triangles. Select the mesh and add a Decimate modifier. Move it to the top of the modifier list, above the Armature modifier. Set Ratio so the face count in the Statistics overlay drops below 20,000, then apply it. For our fox, a ratio of 0.33 gave 19,799 triangles.
4. Limit the bone influences. This step is easy to miss. After the cut, 277 points on our fox were moved by 5 or 6 bones, and Roblox allows 4. In Weight Paint mode, use Weights, Limit Total with a limit of 4, then Weights, Normalize All.
5. Shrink the texture. Open the texture in the Image Editor, use Image, Resize, set it to 1024 by 1024, and save it.
6. Pose it to test. Rotate a few bones in Pose Mode. If the skin still bends cleanly, as on our fox, reset the pose.
7. Export. Use glTF 2.0, or FBX with Roblox’s suggested settings from its Blender page.

Bake3D exports already meet two rules for you. Every export’s skeleton starts with motion_root. It is a joint at 0, 0, 0 on the ground that moves no skin, which is what Roblox asks of a root joint. And our fox, robot, T-rex and person each have one material, as Roblox requires.

For more on Decimate, including how far you can push it, read our guide on reducing polygon count in Blender.

Import a prop

1. In Studio, open the File menu, choose Import, and pick your file.
2. In the preview, check that the size looks right. Roblox measures in studs, and one stud is about 28 cm. If the model is much too big or too small, change Scale Unit, or set a height at export and try again.
3. Leave Import Only As Model on to bring the file in as one asset. Turn on Merge Meshes if you want one MeshPart instead of a Model.
4. Click Import, then place the model and add collisions or scripts as your game needs.

Import a creature or NPC with a custom rig

Roblox supports rigs for bodies of any shape. Its rigging page says a rigged model can be any subject and size. After import, Studio shows the skeleton as Bone objects that you can pose and animate.

1. Set Rig Type to Custom in the importer. R15 is only for human avatar bodies.
2. Check the bones. Turn on Show Constraint Details in the View menu, or open the Animation Editor.
3. Bring in the animation. In the Animation Editor, open the menu, hover over Import, and choose From FBX Animation. Import one clip at a time, because each export holds one track.
4. Play it in your game. A creature has no Humanoid. So Roblox says you must create an AnimationController with a child Animator, then play the animation through the Animator.

Bake3D rigs any body: four legs, six legs, wings, tails and wheels. Its walks, trots and runs are fitted to each rig’s own legs. That makes it a good fit for creature NPCs, which Roblox’s R15 avatars cannot be. To learn how these rigs are built, read auto rigging.

Avatar bodies need Roblox’s R15 setup

An avatar body is a different job. Roblox’s body specs say a character body is made of 15 separate meshes. They are a head, an upper and lower torso, and three parts for each arm and leg. It needs an outer cage, so layered clothing can wrap around it. The whole body can have at most 10,742 triangles.

Bake3D does not make R15 bodies. Its skeleton has its own joint names. For two-armed, two-legged rigs you can switch to Mixamo, Unity or Unreal names. None of that gives you Roblox’s R15 parts, cages or attachments.

There is a path for humans and humanoids, though. Roblox’s Avatar Setup tool can rig, cage and split a mesh into R15 parts for you. Its requirements say the body must:

• follow a general humanoid shape, with two arms, two legs, a torso and a head;
• stay within 10,742 triangles in total;
• stand in an A-pose or T-pose, facing the negative Z axis;
• be watertight, except for the eyes and mouth;
• have no accessories, such as hair, eyebrows or beards, and a neck that is not merged with the shoulders.

AI-made characters usually arrive as one surface, with hair and clothes joined to the body. So expect cleanup in Blender before Avatar Setup accepts them. Bake3D exports face +Z, so turn the model around before you import it.

UGC items: rules, fees and why AI needs care

Selling avatar items on the Marketplace has the strictest rules. From Roblox’s Marketplace policy and fees pages:

• To upload: government ID verification or a linked parental account. Each item costs 80 Robux to upload, or 500 Robux if it uses an emissive mask. Fees are generally not refunded if moderation rejects the item.
• To publish and sell: two-step verification, a refundable publishing advance, and a Roblox Plus or Premium 1000 or 2200 membership.
• Rigid accessories can have at most 4,000 triangles, and Marketplace textures cannot go over 2048 by 2048 pixels.
• Moderation reviews each item, and Roblox says this can take up to 24 hours.

AI-made items need extra care for three reasons:

1. Rights. Roblox says you must have the right to upload an asset, and permission from the owner if the idea is not yours. Crediting the creator or not charging for it does not make a copy allowed. An AI model made from a picture of a famous character is still that character.
2. Responsibility. Roblox’s AI page says you are responsible for the content you deliver to users, even if it is AI-generated.
3. Fit. A 4,000 triangle budget, attachment points and cages are hand work. An AI model is a starting point for an accessory, not a finished one.

If you sell anything made with Bake3D, make it with purchased credits. Assets made with purchased credits come with a commercial, royalty-free license that stays valid after you stop paying. See pricing for details.

Roblox’s own AI tools

Roblox also has AI tools inside Studio. Its Assistant can generate a mesh from a text prompt or from an image, but not both at once. Its maximum triangle count defaults to 10,000. That is handy for quick props that already meet the limits. Use an outside tool when you want a rig for an unusual body and motion fitted to it. It also helps when you want the same file in Blender, Unity or Godot.

Before you publish your game

• Test on the slowest device you support. Place several copies of your model in one spot and check that the game still runs smoothly.
• Check collisions. Animated bones change how a model looks but, as Roblox notes, not its physical shape for collisions.
• Keep your source files. Save the Blender file and the original Bake3D export, so you can make a new version later.

For other engines, see our guides for Unity, Godot and Unreal Engine. To change file formats first, read how to convert GLB to FBX.