To rig a simple model in Blender:
- Set up Blender to Studio's relative scene units before importing a model to rig.
- Create and reposition bones within the mesh object.
- Parent the mesh to the armature to bind the bone armature to the mesh object.
- Assign vertices to specific bones to define which parts of the mesh is driven by which bones.
- Test your rigged mesh to ensure that the bones are properly positioned and influenced within the mesh.
To start the process of creating a rigged mesh, first set up the following in your Blender project:
- Set up Blender's scene unit and unit scale properties to Studio's proportions.
- Import the model into Blender using Blender's file importer.
When setting up Blender projects for Roblox Studio to import, you should modify Blender's default scene units and unit scale properties to ensure they closely align with Studio's scale.
To start a new Blender project and set scene unit properties:
Open a new General project in Blender.
Select the default shape, camera, and lights, then press Delete.
In the left-hand navigation of the Properties Editor, navigate to Scene Properties.
In the Units section, change the Unit Scale to 0.01 and the Length to Centimeters.
For this example, import a robot model into Blender as your mesh object.
To import an existing .fbx model:
In the topbar, click File. A pop-up menu displays.
Select Import, then the file format of the model you're importing. For this example, select FBX (.fbx) and the .fbx reference model. The model displays on the 3D viewport.
Now that your model is within Blender, you must add an armature and bones to your mesh object. An armature is a skeleton-like rigging object that acts as a container for bones, while bones are objects that control the movement and deformation of the group of vertices, or vertex group, that surround the bone.
An armature is a structure required to add bones to your mesh. After you add in an armature, you can create and reposition any number of bones inside of your mesh object.
To add an armature:
At the top of the 3D viewport, select Add → Armature.
For better visualization of the bones, in the left-hand navigation of the Properties Editor, navigate to Armature Object Properties.
In the Viewport Display section, navigate to the Show property, then enable In Front.
When you add an armature to your project, Blender automatically adds one bone to the armature at a default position and scale which will act as the root bone.
To add and position two additional bones:
Click on the bone to highlight it.
At the top of the 3D viewport, click on the Mode dropdown, then switch to Edit Mode.
In the Viewport, click Add → Single Bone. Perform this step twice.
In the Viewport or Outliner, click on a newly created bone to highlight it.
Press G and use your mouse to drag the bone onto the right arm.
Click on the second bone and press G to drag the bone on the left arm.
Click on the top of the right bone so that the tip is highlighted. Press G to drag and orient the bone horizontally toward the right.
Click on the top of the left bone so that the tip is highlighted. Press G to drag and orient the bone horizontally toward the left.
In the Outliner, double-click and rename your bones so they can be easily referenced later.
After you create and position the bone structure, you need to connect the armature to the mesh object by parenting the armature to the mesh object.
In this guide, you should also use Blender's Automatic Weights function when you are parenting an armature, as it automatically adds weights and influences to your mesh.
To parent an armature to a mesh:
At the top of the 3D viewport, click on the Mode dropdown, then switch back to Object Mode.
Press Alt+A (Windows) or Option+A (Mac) to deselect every object.
Hold Shift and select the mesh object and then the armature. The selection order is important.
In the Viewport, right-click on the mesh object. A pop-up menu displays.
Select Parent, then With Automatic Weights.
With your armature connected to the mesh object, you can now assign the mesh vertices of your limbs to be fully influenced by their corresponding bones. As a rigid model, each limb will completely bend and articulate when the bones are rotated, which is ideal for a non-organic character like a robot.
To assign bone influence to the left and right arms:
In Object Mode, select the robot mesh object.
In the Mode dropdown, switch to Edit Mode.
At the top-right of the Viewport, switch to X-Ray view using the Material Preview options.
Drag and select the vertices you want to move with the right bone.
Navigate to the Object Properties panel.
In the Vertex Group section, select the name of the bone you want to assign and click Assign.
Repeat steps 4-6 for the other bone and arm vertices.
Drag and select the rest of the vertices in the center of the robot.
Navigate to the Object Properties panel.
In the Vertex Group section, select the Middle bone and click Assign.
You can test your rig in different poses in Pose mode. It's important to test your rigs after applying or changing influences before exporting.
To test your applied influences:
In Object Mode, select any part of your model.
At the top of the 3D viewport, click on the Mode dropdown, then switch to Pose mode.
Hold Shift and click the bone you want to test to highlight it, then press R to test the rotation.
Press Alt+A to deselect the current bone, then reselect and test another bone.