Easy rigidbody and cloth physics simulation setup with enhanced stability
Physics Dropper is a comprehensive Blender extension that streamlines physics simulation setup for both rigid body and cloth simulations. With an intuitive interface, interactive force fields, and powerful baking tools, it makes complex physics accessible to everyone.
- Quick Setup: Apply active or passive rigid body physics with one click
- Multiple Collision Shapes: Convex Hull, Mesh, Box, Sphere, Capsule, Cylinder, Cone, and Compound
- Fine-Tuned Control: Adjust mass, friction, bounciness, damping, and collision margins
- High-Poly Optimization: Automatic proxy creation using voxel remeshing or decimation for better performance
- Material Presets: Pre-configured settings for Cotton, Denim, Leather, Rubber, and Silk
- Comprehensive Controls: Full control over stiffness (tension, compression, shear, bending)
- Advanced Features:
- Internal springs for soft body-like behavior
- Pressure effects for inflatable objects
- Self-collision detection with adjustable friction
- Air viscosity and quality settings
- Simple Force: Add static force fields at object locations
- Modal Force Mode (F key): Real-time interactive force field placement
- Move mouse to position force in 3D space
- Scroll wheel to adjust force radius
- Ctrl+Click for surface snapping via raycast
- Visual sphere display showing force area
- Customizable: Adjust strength (-1000 to 1000), distance, and air flow
- Dynamic World Shake: Add procedural earthquake motion to all active physics objects
- Axis Control: Enable/disable X, Y, Z axes independently
- Adjustable Intensity: 0-100% strength for subtle to extreme effects
- Non-Destructive: Uses F-curve noise modifiers for easy editing
- Smart Baking: Convert physics simulation to keyframes efficiently
- Only bakes up to current timeline position
- Preserves earthquake effects and external forces
- Automatic cleanup and state reset
- Workflow: Play simulation, pause at desired point, then bake
- Frame Range: Configurable start/end frames for simulation
- Substeps: 1-100 substeps per frame for accuracy
- Solver Iterations: 1-100 constraint solver iterations
- Split Impulse: Reduces extra velocity in collisions
- Blender 4.2.0 - 5.0 (tested up to 5.0, may work with 5.1)
- Download or clone this repository
- In Blender, go to Edit → Preferences → Extensions
- Click Install from Disk (or drag and drop the extension folder)
- Navigate to the downloaded folder and select it
- Enable Physics Dropper in the extensions list
- Find the panel in the 3D Viewport sidebar under the PhyDrop tab
- Select one or more mesh objects in your scene
- Open the PhyDrop tab in the 3D Viewport sidebar (press N if hidden)
- Choose your physics mode:
- Rigidbody: For solid objects that bounce, collide, and fall
- Cloth: For fabric, soft materials, and inflatable objects
- Adjust parameters in the sub-panels (optional)
- Press Drop button or press V key to apply physics
- Press Spacebar to play the animation
- Use Apply button or Shift+V when satisfied to finalize
| Key | Action | Description |
|---|---|---|
| V | Drop | Apply physics to selected objects |
| Shift+V | Apply | Finalize simulation and bake |
| F | Force Mode | Enter interactive force field mode |
All shortcuts are customizable in Edit → Preferences → Add-ons → Physics Dropper
- Select objects that should move and respond to forces
- Choose Rigidbody mode
- Expand Active Settings panel
- Adjust properties:
- Mass: Weight of the object (0.001-1000 kg)
- Friction: Surface grip (0-100)
- Bounciness: Elasticity (0-1)
- Collision Shape: Choose based on object geometry
- Press Drop (V key)
- Select objects that should act as static collision surfaces (floors, walls, etc.)
- Choose Rigidbody mode
- Expand Passive Settings panel
- Adjust collision shape and friction
- Press Drop (V key)
By default, Physics Dropper merges every unselected mesh in the scene into a temporary collision object. In a complex scene that means hiding anything you want left out — and toggling a collection off and on again unhides everything inside it.
The Colliders selector at the top of Passive Settings (rigidbody) or World Collision Settings (cloth) gives you three modes:
| Mode | What Drop uses as collision geometry |
|---|---|
| Auto | Every unselected, visible mesh in the scene (the original behaviour) |
| List | Only the objects and collections you put in the collider list |
| None | Nothing generated — your own passive rigid bodies and collision objects |
The active mode is shown above the Drop button, so you always know what is about to happen without opening a sub-panel.
Collider list (List mode)
- + adds the selected objects
- Collection icon adds the active collection — its contents are resolved when you press Drop, so objects added to it later are picked up automatically
- − removes the highlighted entry, trash clears the list
- Cursor selects everything the list resolves to, so you can check its coverage
Hidden objects can be collider list members. They are used as collision geometry without ever being unhidden or selected — this works for objects hidden with H, objects hidden with the monitor icon, and objects in excluded collections. Your visibility state is never modified.
Notes for None mode:
- Passive rigid bodies only simulate if they are inside the RigidBodyWorld collection. Adding them through the Physics tab puts them there automatically.
- Cloth colliders need a Collision modifier.
- If nothing collidable is found, the Drop still runs and reports a warning.
- Earthquake shakes the generated collider, so it is unavailable in this mode.
An empty list in List mode never falls back to sweeping the scene — Drop reports a warning and generates no collider.
For complex geometry with many polygons:
- Enable Use Proxy in Active or Passive Settings
- Choose optimization method:
- Voxel Remesh: Creates a solid voxel-based proxy
- Decimate: Reduces polygon count while preserving shape
- Adjust Proxy Factor for optimization level
- Select mesh objects to turn into cloth
- Choose Cloth mode
- Select a Material Preset (optional but recommended):
- Cotton: General purpose fabric
- Denim: Stiffer, heavier fabric
- Leather: Thick, resistant material
- Rubber: Stretchy, elastic material
- Silk: Light, flowing fabric
- Fine-tune in sub-panels:
- Stiffness: How resistant the cloth is to deformation
- Damping: How quickly movement dampens
- Internal Spring: Adds volume preservation
- Pressure: For inflatable objects (balloons, cushions)
- Self Collision: Prevents cloth from passing through itself
- Press Drop (V key)
- Press Add Force button in main panel
- Adjust Force Strength and Distance sliders
- Play animation to see effect
- Press F key to enter force mode
- Move mouse to position force field in 3D space
- Scroll wheel to adjust force radius (distance)
- Ctrl+Click to snap force to surface under cursor
- Left Click to confirm placement
- Right Click or Esc to cancel
Force fields appear as visual spheres showing their area of influence.
- Check Enable Earthquake in main panel
- Toggle axes (X, Y, Z) for directional shake
- Adjust Intensity (0-100%)
- Play animation to see all active physics objects shake
- Effects use F-curve modifiers and can be edited in Graph Editor
When you're satisfied with your simulation:
- Play the animation to the point you want to bake
- Pause the timeline
- Press Bake to Keyframes button
- Simulation is now permanent keyframe animation
- Safe to modify further or use in rendering
Benefits:
- Faster playback and rendering
- No need to recalculate physics
- Can edit keyframes manually
- Preserves earthquake and force effects
| Button | Function |
|---|---|
| Drop | Apply physics simulation to selected objects |
| Apply | Finalize simulation and clean up |
| Reset | Remove all physics from scene |
| Exit Drop Mode | Keep simulation running but exit edit mode |
| Pause/Play | Toggle simulation playback |
Physics Dropper uses a robust, thread-safe architecture:
- State Management: Thread-safe
PhysicsStateclass tracks all simulation data - Safe Operations:
SafeOperationcontext manager ensures error handling - Property Validation: All property updates are validated to prevent errors
- Custom Icons: Professional UI with custom icon integration
- Modular Design: Separate modules for rigidbody, cloth, earthquake, and baking systems
physics_dropper/
├── __init__.py # Main entry point and registration
├── operators.py # 13 operator classes for user actions
├── panels.py # 12 UI panel classes
├── properties.py # 80+ scene properties
├── rigidbody.py # Rigid body physics system
├── cloth.py # Cloth simulation system
├── earthquake.py # F-curve noise modifier system
├── bake_utils.py # Keyframe baking utilities
├── utils.py # State management and helpers
├── logger.py # Error handling and logging
├── constants.py # Configuration constants
├── icons/ # Custom UI icons
└── blender_manifest.toml # Extension metadata
- Use proxy objects for high-poly meshes
- Reduce substeps and solver iterations for faster preview
- Increase quality settings only for final renders
- Bake simulations to keyframes for faster playback
- Start with low force values and increase gradually
- Use Split Impulse in World Settings to reduce jitter
- Increase Solver Iterations if objects pass through each other
- Add more Substeps for fast-moving objects
- Always have a collision object (passive rigidbody or cloth collision)
- Enable Self Collision for complex folds
- Use Pin Group (vertex group) to anchor parts of cloth
- Adjust Collision Quality if penetration occurs
- Use Ctrl+Click in Force Mode to snap to surfaces precisely
- Adjust Flow parameter to convert force to air flow for cloth
- Multiple force fields can be combined for complex effects
- Animate force strength for dynamic effects
If you find Physics Dropper useful, consider supporting its development:
Contributions are welcome! Please feel free to submit issues, feature requests, or pull requests.
Physics Dropper is licensed under the GPL-3.0-or-later license.
Copyright © 2024 Elin Höhler
- Added a Colliders selector (Auto / List / None) to Passive Settings and World Collision Settings
- List mode builds the collider from a list of objects and collections you pick, with Add Selected / Add Collection / Remove / Clear / Select buttons
- Hidden objects, and objects in excluded collections, can be used as colliders without ever being unhidden — visibility state is never touched
- None mode simulates against your own passive rigid bodies and collision objects
- Collider mode is shown above the Drop button
- Drop reports a warning when no collider will be generated and the scene has nothing to collide with
- Migrated to Blender 4.5+ extension format
- Maintained backward compatibility with older versions
- Enhanced force mode with Ctrl+Click raycast surface snapping
- Improved keyframe baking system
- Updated for Blender 4.5 compatibility
- Various bug fixes and performance improvements
Made with ❤️ for the Blender community