Configure Active Rigid Body in Blender

Setting up an active rigid body in Blender allows 3D objects to react dynamically to gravity, forces, and collisions within a physics simulation. This guide provides a straightforward walkthrough on how to assign rigid body physics to any mesh, set its type to active, choose the correct collision bounds, and adjust simulation parameters such as mass and bounciness for realistic movement.

Step 1: Select the Target Object

  1. Open your scene in Blender.
  2. Left-click to select the 3D mesh you want to participate dynamically in the physics simulation.

Step 2: Add Rigid Body Physics

  1. Navigate to the Properties Editor on the right side of the interface.
  2. Click on the Physics Properties tab (represented by a blue icon of an orbiting planet).
  3. Click the Rigid Body button to enable physics on the selected object.

Alternatively, you can select the object in the 3D Viewport and go to the top menu: Object > Rigid Body > Add Active.

Step 3: Set Rigid Body Type to Active

Under the Settings panel within the Rigid Body settings:

  • Locate the Type dropdown.
  • Ensure it is set to Active. Active objects are affected by gravity and external forces, causing them to move and interact with other rigid bodies.
  • Make sure the Dynamic checkbox is enabled so the object moves during playback.

Step 4: Adjust Mass and Physical Attributes

  • Mass: Enter the weight of the object in kilograms. Heavier objects will transfer more momentum during collisions.
  • Animated: Check this box only if you want keyframed animations to override physics temporarily before releasing the object into dynamic simulation.

Step 5: Configure Collisions

Expand the Collisions panel to control how the object's boundaries are calculated:

  1. Shape: Choose the collision shape that best fits your object's geometry:
    • Convex Hull: The default and most computationally efficient shape for general non-concave meshes.
    • Mesh: Best for concave or complex geometries, though more computationally demanding.
    • Box, Sphere, Capsule, Cylinder: Best for primitive shapes to maximize simulation performance.
  2. Surface Response:
    • Friction: Adjust how much the surface resists sliding against other objects (0 is frictionless, 1 is high resistance).
    • Bounciness: Adjust how elastic collisions are (0 produces no bounce, 1 creates maximum bounce).

Step 6: Test the Simulation

  1. Move the playhead to frame 1 in the Timeline.
  2. Press the Spacebar to play the animation and observe the active rigid body falling and reacting to the environment.