Blender Rigid Body Physics: A Step-by-Step Guide to Collision Simulation

What will you learn in this guide?

Blender’s Rigid Body system uses physics simulation to create the movement and orientation of solid objects in a scene. Rather than bending or deforming geometry, it moves objects as a whole. Because the system works with animation, bodies can be used with parent-child relationships, animation constraints, and drivers.

This guide covers assigning mesh objects as Active or Passive, checking the collections that define the simulation’s scope, and using the bake options in the Cache panel. The examples are suited to scenarios such as a decorative object falling in an architectural visualization scene or a stationary tabletop. These are example use cases; the source guides do not guarantee specific scene outcomes.

Requirements and getting started

This guide is based on the Rigid Body and Rigid Body World pages in Blender’s official manual. The sources do not specify a particular Blender version, account type, fee, or hardware requirement. Therefore, no additional assumptions about version or performance are made here.

Only mesh objects can be included in the simulation. Before you begin, identify the objects that will move and the stationary objects that will serve as collision surfaces. For example, in an interior presentation, an object that tips over on a table could be set as Active, while the tabletop could be set as Passive. This distinction makes it easier to plan which objects will be moved by physics.

Step-by-step Rigid Body setup

1. Select the mesh objects to include in the simulation. Check that the objects you want to include in the Rigid Body system are meshes. If every target object in the scene needs to participate, review the body type and collection settings for each one.

2. Choose the body type. You can add a Rigid Body to a selected object from the Physics tab in Properties or use the Rigid Body options in the Object menu. Add Active is for objects that will take part in a dynamic simulation; Add Passive defines objects intended to remain stationary. Setting a falling decorative object to Active and the floor or furniture surface it will touch to Passive is a straightforward way to get started.

3. Consider the Animated option as needed. The official manual states that both Active and Passive bodies can be driven by the animation system when the Animated option is enabled. If you use this option, consider the roles of animation and physics simulation together. For dynamic bodies, the simulation controls the object’s location and orientation during playback. Keep in mind that the object’s location and rotation values do not change directly during this process.

4. Check the Rigid Body World collections. The Rigid Body World panel in the Scene tab defines the collections of bodies and constraints included in the simulation. When you add a Rigid Body to an object, a group named RigidBodyWorld is created by default, and bodies are added to it. However, the Collection field in the panel determines which collection is used in the simulation. As a result, bodies or constraints that aren’t in the listed collection may not be included in the calculation. You can also create multiple Rigid Body World collections and place objects in different collections.

5. Adjust the timing and accuracy settings. The Speed setting changes the flow of time for the physics motion. Substeps Per Frame determines how many simulation steps are used for each frame; increasing the value can provide a more detailed calculation, but it also slows the process. Solver Iterations controls the number of iterations used to solve constraints at each step. Higher values can help stabilize constraints and stacked objects, but may also increase calculation time.

6. Use Split Impulse with care. This setting helps reduce excess velocity that can occur during collisions and may improve results in some scenes. However, it can reduce simulation stability somewhat. Rather than leaving it enabled all the time, test it in scenes where it’s needed. Check the results especially when many objects are stacked on top of one another.

7. Apply object transforms when needed. Physics simulation controls the movement of a dynamic object in the scene, but that movement is not automatically written to the object’s own location and rotation values. If you need to transfer the transforms produced by the simulation to the object, consider using the Apply Object Transform operator. Also note that scale affects the simulation, but is controlled by the animation system.

Baking the cache

The Cache subpanel in Rigid Body World defines the frame range in which the simulation starts and ends. Baking calculates the physics motion across the specified range and saves the result to the cache. Make sure you’re in Object Mode before starting the bake. Save your project file beforehand, too: according to the Blender manual, a cache created in an unsaved file may remain in memory and can be lost if the file isn’t saved.

Once baking is complete, you can clear the cache with Delete Bake. The manual also describes options for calculating up to the current frame, baking from the current cache, and baking or deleting all physics caches in the scene. Check the start and end frames in the Cache panel before starting so you know exactly which range the calculation will cover.

Common mistakes

• An object doesn’t appear in the simulation: Check that it’s a mesh and is included in the collection selected in the Rigid Body World panel. Also check which collection contains the constraints.

• Baking won’t start: Switch to Object Mode first. If the file hasn’t been saved yet, save it; otherwise, the cache in memory may be lost.

• Stacked objects are unstable: Increasing Solver Iterations can improve the stability of constraints and stacks. Change the setting and test the result in your scene.

• Collision motion isn’t producing the desired result: Substeps Per Frame affects accuracy, while Split Impulse affects the reduction of excess velocity during collisions. Test the effects of these settings separately; Split Impulse can reduce stability.

• The object’s location and rotation values aren’t updating as expected: The simulation may control motion without directly changing the object’s values. Consider using the Apply Object Transform operator to transfer the transforms to the object.

Use in architectural and visualization workflows

Rigid Body can be used to create falling, collision, or stacking motions in architectural animations. In an interior presentation, setting the moving decor to Active and the surface it will touch to Passive helps distinguish the roles of objects in the scene. A similar setup can be tried in product or furniture visualizations. However, results should be assessed in the context of the scene and the settings used.

The sources don’t specify any particular hardware requirements or performance comparisons. In your workflow, keep in mind that increasing the simulation steps can extend processing time, that the file should be saved before baking, and that the objects intended for the simulation need to be in the correct collection. The sources also provide no information about a specific software version or paid license, so this guide makes no additional claims on those points.

Next steps

Start by observing the basic behavior in a simple scene with one Active and one Passive mesh object. Then adjust the frame range, Substeps Per Frame, and Solver Iterations as needed, and compare the results. When you change settings, compare each result under the same scene conditions. Finally, check the collections, save the file, and bake the simulation. This makes it easier to investigate body type, scope, timing, and caching separately if something goes wrong.

Sources and license

This guide is adapted into Turkish from the Rigid Body World and Rigid Body introduction pages in Blender’s official manual. Both sources are published under the CC BY-SA 4.0 license.