Frosting Manual

Installation

Frosting installs like any other Blender add-on. No external libraries, no compiled binaries, no internet connection required.

1. Open Blender and go to Edit › Preferences › Add-ons.
2. Click Install… (top right) and pick the frosting.zip file.
3. Enable the Frosting checkbox once it appears in the list.
4. Press N in the 3D Viewport — a new Frosting tab is added to the sidebar.

Quick start

The shortest path from "empty scene" to "objects raining onto the floor". Six steps. Roughly a minute.

1. Put the objects you want to scatter into a Collection.
2. Have a Floor mesh in the scene — a plane, a terrain, a bowl, anything that catches.
3. Open the Frosting panel and assign Collection, Floor, and an Empty as the emitter.
4. Set Count (try 100) and press Scatter.
5. Play the timeline. Watch them fall.
6. When the pile settles, press Freeze here to lock the pose, or Bake animation to keep the fall as keyframes.

Distribution modes

Frosting has four distribution modes. They share the same physics and the same source collection — only the way instances are introduced into the scene changes. Pick a mode in the DISTRIBUTION MODE row at the top of the panel.

Emitter mode

The default and most flexible mode. An Empty object defines the spawn position, and instances are released from there over one or more frames.

• Window (frames) spreads the release across N frames so instances don't all collide at frame 1.
• With Window > 1, instances exist before their spawn frame but are hidden and kinematic — they follow the Empty without falling. This is normal.

Curve mode

Use this when you want a precise spatial path instead of a single point source. Any open or closed Bezier or NURBS curve works. The number of spawn points equals Count, distributed evenly along the curve length.

• Click Create curve to drop a starter Bezier into the scene.
• In Curve mode all instances spawn at the same frame (the emission window is disabled).
• A Live preview button shows where the spawn points will land before you commit.

Brush mode

A non-simulated mode for precise placement. Press Paint instances and stamp objects onto the floor with the cursor.

Volume mode

For dense, structured stacks: bricks in a pallet, rocks in a crate, ice cubes in a glass. Defines a 3D box on the floor and fills it with a regular grid of instances that then collapse under gravity.

1. Drag on the Floor to set the XY base of the cube.
2. Release and move the mouse up to set the Z height.
3. Click to confirm. The cube fills with a grid of instances.
4. Press Start simulation to make the stack collapse.

05

The same volume-cube placement is also exposed as a workspace tool — the Volume Grid tool — so you can keep dropping stacks without leaving the mode.

Panel reference

Field-by-field description of every control in the Frosting sidebar. Some sub-panels appear or disappear depending on the active distribution mode.

Sub-panel Inputs

Collection	Source collection — the objects to distribute.
Floor	Mesh that catches the instances. Auto-converted to a passive rigid body.
Collider (collection)	Optional. Extra colliders (walls, props, characters) that also block the falling objects.
Animated colliders	Tick if any collider has keyframes or constraints, so Bullet re-bakes them every frame.
Empty / Curve	The emission source. Hidden in Brush and Volume modes.
Create curve	(Curve mode only) Drops a starter Bezier into the scene and assigns it.

Sub-panel Emission EMITTER / CURVE

Count	Number of instances to spawn.
Seed	Randomisation seed. Same seed + same scene = same result.
Window (frames)	How many frames the emission is spread over. Emitter only — Curve always releases at once.

Sub-panel Brush BRUSH MODE

Radius	Brush circle radius in world units.
Spacing	Minimum distance between two painted instances. Smaller = denser paint.
Align to normal	Tilt each instance to follow the floor's surface normal.

Sub-panel Variation

Scale min / max	Each instance gets a uniform random scale in this range.
Rotation	How the spawn rotation is computed. Three modes: Random — fully random Euler. Align to normal — face the local surface normal. Upright — keep Z up, randomise Z rotation.
Linked duplicates	Re-use source mesh data. Saves a lot of memory at high counts; trades off the ability to edit instances independently.

Sub-panel Physics

Collider	Collision shape used by Bullet: Convex hull — recommended. Fast and stable. Exact mesh — precise but slow, can be unstable. Box — bounding box. Sphere — bounding sphere.
Mass	Per-instance mass.
Friction	0 = ice, 1 = sandpaper.
Bounciness	0 = clay, 1 = rubber ball.

Solver (nested)

Substeps	More substeps = more stable, slower simulation.
Iterations	Solver iterations per substep.

Sub-panel Simulation end

Start / End	Simulation range. Stays in sync with the scene timeline while no session is running.
Auto-freeze	When the timeline reaches Frame, freeze the session automatically. Handy for batch / overnight bakes.
Frame	The frame at which Auto-freeze fires.

Sub-panel Action

The Action sub-panel changes depending on whether a session is running.

When idle (no session)

Scatter	Run the scatter for the current mode.
Delete last	Remove the collection produced by the most recent Scatter. Sources are not touched.
Clear cache	Free the Bullet point cache. Use this if the simulation behaves oddly after editing settings.

During a live session

Freeze here	Stop the simulation and snapshot the current pose. Instances become regular keyframe-free objects.
Bake animation	Convert the running simulation into keyframes on every instance, then end the session. Plays without the rigid body world.
Cancel session	Throw away the scatter and restore the scene.

Movement tools

Toggle MOVEMENT TOOLS at the top of the Frosting panel to enter a post-production mode. The distribution panels disappear and three workspace tools are added to the 3D Viewport toolbar (left edge, T).

Tweak

RELOCATE ONE

Click and drag a single instance to a new position. Useful for the one rock that landed in a stupid place.

Plough

SCULPT WITH PHYSICS

Paint a force field on the floor while the sim runs. Push piles together, carve trails, sculpt with physics.

Inputs and simulation

Visible only when Movement Tools is enabled.

Tips & gotchas

Small facts that save big headaches. None of these are bugs; they are consequences of how Bullet and the Blender dependency graph interact.

Support

Frosting is published under the GNU GPL v2 (or later). The full license text ships with the addon in license.txt.

Thank you for using Frosting. Happy scattering.