Table of contents

Introduction

Newton is a 2D physics simulator for Adobe After Effects CS5 or later.

Newton interprets 2D layers of the current composition as rigid bodies in a physical world. These bodies can collide with each other, slide, bounce, and react to gravity. Bodies can also be connected to each other using joints. Newton can deal with various types of bodies: some types allow bodies to be animated in After Effects while reacting to physical forces, others are entirely controlled by the solver. Newton also provides a simple, clean, and easy to use interface, offering fast OpenGL preview and intuitive controls. Once simulation is completed, Newton export the animation to After Effects using standard keyframes.

Newton Interface
Newton Interface

Bodies Back To Top

Newton transforms composition 2D layers (except audio, guide, null and video-disabled layers) into physical objects called bodies. These bodies can bounce, slide, and collide with each other. To change the properties of a body, you must first select it in the body list or directly in the preview. One of the most important body properties is the body type.

General Properties Back To Top

Type

Newton supports the following types of body:

Density

This parameter is used to determine the mass of a non-static body. High-density body doesn't fall down faster than low-density body (they fall at the same speed), however when collision occurs, the difference of density is easily noticeable.

Friction

This parameter is used to make bodies slide along each other. A value of 0 turns the friction off, and a value of 1 makes the friction strong.

Bounciness

This parameter is used to make bodies bounce. A value of 0 means no bounciness (e.g., a ball falling on the ground will not bounce), a value of 1 means maximum bounciness (e.g., a ball falling on the ground will bounce indefinitely).

Color

This parameter sets the body color used in the simulation preview.

Mesh Precision

This parameter is used when a body is formed by a shape with round corners. Default value is 2. Higher value increases precision but performance may suffer. For complex shapes, it is highly recommended to keep this value as low as possible.

Linear Velocity

This parameter sets the linear velocity of a body. Force is applied to the center of mass. You can also set the velocity directly in the preview by using the Velocity tool (P).

Note:

Angular Velocity

This parameter sets the angular velocity of a body. Force is applied to the center of mass.

Linear Damping

This parameter is used to reduce the linear velocity of a body.

Angular Damping

This parameter is used to reduce the angular velocity of a body.

AEmatic Damping

This parameter is used only by AEmatic bodies. It corresponds to the damping coefficient of the joint connecting the motion path set in AE (desired path) and the motion path determined by the solver.

AEmatic Tension

This parameter is used only by AEmatic bodies. It corresponds to the tension of the joint connecting the AE motion path and the motion path determined by the solver.

Note:

Advanced Properties Back To Top

Collision Group, Collide With

You can assign a collision group to a body (five groups are available), and specify which groups the body should collide with. By default every body belongs to the same group and can collide with every other groups.

Fixed Rotation

This parameter is used to prevent body rotation.

Gravity Scale

This parameter allows you to set a custom gravity per body. A value of 0 turns gravity off for the body.

Note that negative values are allowed.

Use Convex Hull

This parameter allows you to approximate the geometry of a complex body, using the convex hull of the shape vertices. In some situations, when working with text for instance, this option can highly increase performances while producing realistic simulation.

Magnetism Type

This parameter allows you to transform a body into a magnet that can either attract or repulse other bodies.

Magnet Intensity

This parameter specifies the intensity of magnetism.

Magnet Distance

This parameter determines the maximum distance at which the magnet is active.

Accept Magnetism

This parameter specifies whether the body is sensitive to magnetism of other bodies.

Joints Back To Top

Newton allows you to create joints between bodies. A joint is used to add a constraint between two bodies.

To add a new joint, select two bodies and use one of the Add Joint buttons above the joint list. To remove a joint, select it in the joint list (or press W when one of the connected bodies is selected), and click on the Remove Joint button (or press Alt W).

To modify joint properties, you must first select the joint, and then change its properties.

Notes:

Distance Joint Back To Top

A distance joint implies that the distance between two points (joint anchors) on two bodies must be constant. This is not always true since you can give elasticity to the joint, and obtain a soft distance joint.

Tension

This parameter allows you to give elasticity to the joint. This can be used for instance to create a soft body (by connecting several small bodies with soft distance joints).

Damping

This parameter is used to reduce or soften the amount of motion.

Collide Connected

This parameter specifies whether the two connected bodies should collide with each other.

Pivot Joint Back To Top

A pivot joint forces two bodies to share a common anchor point or pivot point. The joint angle is the relative rotation between the two bodies and can be restricted to a specific range.

Enable Limit

This parameter is used to force the joint angle to remain between a lower and upper bound.

Lower Angle

This parameter specifies the lower bound of the joint angle.

Upper Angle

This parameter specifies the upper bound of the joint angle.

Enable Motor

This parameters determines whether the joint motor is enabled.

Motor Speed

This parameters allows you to specify the joint speed.

Max Motor Torque

This parameters allows you to specify the maximum motor torque allowed.

Collide Connected

This parameter specifies whether the two connected bodies should collide with each other.

Piston Joint Back To Top

A piston joint allows for relative translation of two bodies along a specified axis. Its parameters are similar to the pivot joint parameters, except that rotation is replaced with translation.

Enable Limit

This parameter is used to force the joint translation to remain between a lower and upper bound.

Lower Translation

This parameter specifies the lower bound of the joint translation.

Upper Translation

This parameter specifies the upper bound of the joint translation.

Enable Motor

This parameters determines whether the joint motor is enabled.

Motor Speed

This parameters allows you to specify the joint speed.

Max Motor Force

This parameters allows you to specify the maximum motor force allowed.

Collide Connected

This parameter specifies whether the two connected bodies should collide with each other.

Spring Joint Back To Top

A spring joint constrains two bodies to move like they were connected by a spring.

Springiness

This parameter controls the strength of the spring.

Damping

This parameter allows you to reduce the amplitude of oscillations.

Desired Length

This parameter specifies the length of the spring when it is inactive.

Preview Back To Top

Newton provides an OpenGL view to preview the result of the simulation. The view handles mouse and keyboard events. For instance, you can zoom and pan in the view, or select and move bodies in the scene. A contextual menu also provides some common operations (accessible from both the preview and the body list).

Tool Buttons

There are five tool buttons above the preview, each one being used for a specific operation :
Tool Buttons
Tool Buttons
Notes

Zoom

You can zoom in and out the preview by using either the zoom slider, the mouse wheel, or the dedicated buttons. The Best Fit Zoom button allows you to automatically scale the scene to fit the view.

Zoom
Zoom

Background Color

By default the preview background color is equal to the current background color of the composition. You can change it by using the color picker next to the zoom slider.

Background Color
Background Color

Preview Options

The following visualization options are available in the View Options popup menu:
Preview Options
Preview Options

Simulation Commands

To start the simulation, click on the Play button (shortcut key: 0). The other available commands allow you to restart (shortcut key: Enter (numpad) or Home), step one frame (shortcut key: 1 or PageDown) and loop the simulation from 0 to current time (shortcut key: 2).

Simulation Commands
Simulation Commands

Scene Snapshots

The Take Scene Snapshot button above the preview allows you to save temporarily the current scene settings. To restore a Scene Snapshot, double-click on it. You can delete it by using either the context menu of the snapshots list (right click > Delete), or the delete/backspace key. This feature is useful for creating multiple versions of the same scene without having to export separated settings file for each one.

Scene Snapshots
Scene Snapshots

Context Menu

A context menu regrouping some common operations is available by right-clicking in the preview. This context menu is also attached to the body list.

Context Menu
Context Menu

Gravity Back To Top

Gravity is a force acting on all bodies. You can set its magnitude and direction using the text fields, the gravity view or the Gravity tool (G). You can animate it either by capturing mouse movement, or using the Inherit From checkbox that allows you to select a composition layer.

Gravity
Gravity

Magnitude

This parameter specifies the magnitude of the gravity vector.

Direction

This parameter specifies the direction of the gravity vector. When changing the gravity in the gravity view or with the Gravity tool, hold the Shift key to snap the vector to the nearest axis.

Inherit From

Use this option if you want the gravity to inherit its value from the position of a layer. For instance, position [0,10] represents the default gravity which has magnitude 10 and direction 90°.

Capture, Apply

When Capture is active, every mouse movement in the gravity view is recorded. By clicking on the Apply button, the recorded values are assigned to a new null layer that is automatically selected in the popup menu.

Note:

Solver Back To Top

Internally Newton uses part of the Box2D library, a 2D physics engine initially developed for game programming.

Time Divider

This parameter affects the time step used for solving physical equations. It can be viewed as a time remap controller. For instance, a value of 5 produces a slower animation similar to high precision slow motion. Default value is 1.

Collision Tolerance

This parameter specifies the constraint and collision tolerance of the solver. Default value is 50. Smaller value often reduces gap between touching bodies, but may introduce overlap or instability when collision occurs.

Substeps

This parameter allows you to subdivide the time step. Default value is 2. Higher value may produce a simulation of higher quality at the expense of extra computation time.

Actions History Back To Top

You can use the Actions History panel to quickly jump between past operations. The maximum levels of undo is set to 100 by default, but this can be changed in Newton Box2 dialog. To clear history, right-click in the view and chosse Clear.

Actions History
Actions History

Loading and Saving Settings Back To Top

Once you have assigned settings to bodies (including position and rotation), you can save them as an XML file. When saving settings, Newton also stores unique identifier for each body. This allows you to change your composition (adding new layers for instance), and reapply saved settings on the appropriate bodies.

If the Auto Load/Save Settings option is active, Newton will try to load (at startup) or save (at quit) the last scene settings. This option is particularly useful when you need to jump frequently back and forth between Newton and the same After Effects composition (the project must also be the same).

Load/Save Settings
Load/Save Settings

Separating Shapes Back To Top

When a layer contains more than one mask or path, the Shapes Separation dialog pops up. You must specify whether Newton should interpret each shape of a layer as an individual layer (AE) or body (Newton). If you don't separate shapes, the compound shape will be considered.

Shapes Separation
Preprocessing step: shapes separation

Applying Result Back To Top

When your are satisfied with the simulation, specify the frame range to be exported and hit Render. Two additional options allow you to specify whether the result must be applied to a copy of the original composition, and whether motion blur must be enabled for moving bodies.

The simulation is solved again, but this time animation data are stored in memory. At the end of the simulation, stored values are converted to standard After Effects keyframes, and Newton quits.

Render
Export Newton animation to After Effects keyframes

Keyboard Shortcuts Back To Top

You can open the Keyboard Shortcuts dialog either using the menu command Help > Keyboard Shortcuts... or using Alt . shortcut. The following table enumerates the available shortcuts.

Notes:
KeyResult
Setting type of selected bodies
SSet to static
KSet to kinematic
DSet to dynamic
ASet to dormant
MSet to AEmatic
ESet to dead
Moving/Rotating selected bodies
←↑→↓Move by 1 pixel
Shift ←↑→↓Move by 10 pixels
+/-Rotate by 1 degree
Shift +/-Rotate by 10 degrees
Selecting bodies
CSelect bodies with the same color
LSelect bodies with the same label
QSelect bodies with the same collision group
TSelect bodies with the same type
IInvert selection
Selecting joints
WSelect joints of selected bodies
Alt WRemove joints of selected bodies
FSelect joints with the same type
Selecting tools
VSelect the Selection Tool
HSelect the Hand Tool
Space BarSelect temporarily the Hand Tool
YSelect the Joint Anchor Tool
GSelect the Gravity Tool
PSelect the Velocity Tool
Simulation commands
0Start or Pause
HomeGo to first frame
1 or Page DownGo to next frame
2Loop simulation from 0 to current time
Joint Anchors
XMove AEmatic anchor to center of mass
Alt moveRelative shift of selected AEmatic anchors
Move anchorA and anchorB of selected distance joints
Relative shift of selected pivot joints
Move anchorA and anchorB of selected spring joints
Creating distance joints
Alt ClickShortest distance
Alt Shift ClickShortest distance on anchorA-anchorB line
Ctrl Alt ClickBetween every pair
Ctrl Alt Shift ClickTriangulation
Show or hide panels
Alt 1Bodies
Alt 2Joints
Alt 3Global Properties
Alt 4Body Properties
Alt 5Joint Properties
Alt 6Export
Alt 7Info
Alt 8Actions History
Ctrl Alt 1Toggle All
Alt 0Reset to default layout
Menu Commands
Ctrl Alt POpen Preferences
Alt OLoad Settings
Alt SSave Settings
F1 (win), Cmd ? (mac)Open User's Guide
Alt .Open Keyboard Shortcuts
Ctrl Alt QQuit Newton
Miscellaneous
Delete or BackspaceRemove selected scene presets
Crtl Alt Shift +/-Increase or decrease line width of selected open shape
ZReset pan and zoom

Troubleshooting Back To Top

If you detect a bug or have any questions about Newton, do not hesitate to contact our customer support team.