How to make an AI 3D model work in Roblox (Meshy, Tripo, Blender)

AI 3D generators such as Meshy and Tripo turn a prompt or picture into a textured model in minutes. Dropping that model straight into Roblox Studio rarely goes well: it comes in at the wrong size, floats above the floor, carries far more triangles than a pet needs and sometimes arrives without its texture. This tutorial fixes each of those in Blender, step by step, with the export and import settings Roblox documents. Settings are checked against the Roblox Creator Hub as of October 2026.

Why do AI 3D models fail in Roblox?

Generators optimize for a good-looking render, not for a game engine: they don't know about Roblox's studs, triangle budgets, single-material MeshParts or rig rules. Each of those needs a fix before import.

Hard limits come from Roblox's modeling specifications: no mesh over 20,000 triangles and no vertex influenced by more than 4 bones. Roblox's texture specifications allow textures up to 4096 × 4096 pixels since 2026 (parts of the page still say 1024) and require OpenGL-style tangent-space normal maps. For a pet, 1024 px is already more than players see.

Step 1: Import and clean the mesh

In Blender, set Scene Properties > Units > Unit System to None so Blender units line up with studs, as Roblox's Blender guide recommends. Import the GLB with File > Import > glTF 2.0. Then, in Edit Mode with everything selected:

1. Mesh > Clean Up > Merge by Distance. AI meshes often have duplicate vertices along UV seams; merging closes the cracks.
2. Select > Select Loose, then delete floating bits the generator left around the model.
3. Mesh > Normals > Recalculate Outside to fix faces that render dark or see-through.
4. If the model came in as several objects, join them with Ctrl+J. One mesh with one material imports as one MeshPart.

Step 2: Reduce triangles

Add a Decimate modifier in Collapse mode. Its panel shows the face count; set the ratio to target ÷ current (for example 4,000 ÷ 16,000 = 0.25), turn on Triangulate and apply it. Collapse keeps the UV map, so the existing texture still fits; check the seams for stretching. Pick the target from what the model is:

The Zombie Piranha pet from our homepage before and after Proppo's Roblox optimize at the pet preset: 51% fewer triangles with the same silhouette.

Check the result from the distance the game camera will see it, not in a close-up. If decimation chews up thin parts such as antennae or fins, lower the ratio less there: decimate the body and the details separately, then join them.

Step 3: Bake one texture at 1024 or less

A MeshPart uses one material, so the goal is one UV map and one color texture. If you only decimated, open the texture in the Image Editor and use Image > Resize to 1024 px or less (512 px is plenty for most pets), then save it as PNG.

If you remeshed, or the model has several materials, bake:

1. Unwrap the low-poly mesh (UV > Smart UV Project) and add a new 1024 × 1024 image in an Image Texture node of its material.
2. Switch the render engine to Cycles. In the Bake panel choose Diffuse and leave only Color ticked under Contributions.
3. Select the original high-poly model, then the low-poly one, tick Selected to Active, set a small Extrusion and press Bake. Save the image.
4. Optional: bake a Normal map the same way to keep surface detail. Roblox reads OpenGL-style normal maps, which is Blender's convention.

Generators often deliver PBR textures where roughness and metalness are packed into one image, as glTF does. Roblox's SurfaceAppearance wants them as separate grayscale images; split the channels or keep only the color map. See texture baking in the glossary.

Step 4: Scale to studs and set the pivot

With Unit System None and FBX Unit Scale on export, 1 Blender unit becomes 1 stud. Scale the model to the height you want: a default avatar is about 5 studs tall, so pets usually land at 2 to 4 studs (Proppo uses 3 for pets and 3.5 for eggs).

1. In Edit Mode, select the lowest vertices, press Shift+S > Cursor to Selected, then move the cursor to the center in X and Y.
2. In Object Mode, Object > Set Origin > Origin to 3D Cursor. The pivot is now at the bottom center.
3. Move the object to 0, 0, 0 (Alt+G) and face its front the way your other models face.
4. Ctrl+A > All Transforms, so location, rotation and scale are baked into the mesh.

Step 5: Check bones and weights

Skip this step for static models. For a rig, Roblox's specifications require frozen bones (scale 1, rotation 0), a root bone at 0, 0, 0 with no influences, and at most 4 bones per vertex. In Weight Paint mode use Weights > Limit Total with a limit of 4, then Weights > Normalize All.

Step 6: Export FBX with Roblox settings

Select the mesh (and armature, if any) and use File > Export > FBX. These are the settings from Roblox's export requirements:

Static models can also go out as GLB, which Roblox notes needs no extra scale settings. FBX is the safer choice once a rig is involved.

Step 7: Import into Studio and check

In Studio, use File > Import with Scale Unit set to Studs. Before placing the model, check:

• The importer shows no warnings in the hierarchy; hover any icon to read it.
• The model stands on the ground and is the right size next to a 5-stud avatar.
• The texture is there. If not, add a SurfaceAppearance and set its ColorMap.
• CollisionFidelity is Box or Hull for pets and small props, and CanCollide is off for pets that follow players.

The import guide explains every importer setting, and the triangle and texture guide covers budgets for phones.

What if the model still looks wrong in Roblox?

Most leftover problems trace back to one skipped step: transforms not applied, textures not embedded or weights over the limit.

Is there a faster way than doing this by hand?

Yes: tools built for Roblox run these steps automatically. Proppo is our own product: it generates the model with AI and then runs our own Blender pipeline on it.

That pipeline merges by distance, recalculates normals, decimates to the preset budget, limits skinned vertices to 4 normalized influences, triangulates, resizes textures to the preset size, scales to studs with the origin at the bottom center, applies transforms and writes an FBX with FBX Unit Scale, copied and embedded textures and no leaf bones. Optimize costs 5 credits, an auto-rig 10 credits and rarity variants 5 credits per set. Doing it by hand in Blender, as above, is free and gives you full control. For a broader comparison of generators, see AI 3D tools for Roblox and Roblox Cube vs AI generators.