Drag and draw to create Objects and Joint

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With simPHY you can create simulation scenes with mouse using simple drawing tools like boxes, circles, polygons, gears etc, optionally connected by joints like spring or ropes . Composite bodies can be created by adding multiple fixtures or using constructive area geometry. You can also Edit and make changes by rotating, scaling, moving, cutting or cloning your objects.

Supported Objects Type

1. Box
2. Disc/Ring
3. Polygons
4. Chains and gears
5. You can also create special complex objects by adding multiple fixtures or using constructive area geometry

Supported Joints Type

1. Spring and Distance Joint
2. Rope joint
3. Prismatic Joints
4. Revolute Weld and Wheel Joint
5. Pulley Joint

Editor Options

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SimPHY supports all major editor options for objects and joints to make experience better.

• Multiple Selection
• Cut
• Copy
• Paste
• Redo
• Undo
• Delete

All these operations can be done using well known keyboard shortcuts like Ctrl+C for copy, etc

Fields supported

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• Gravity:

  The gravitational force on an object is calculated as
  Force = mass x gravity x gravityFactor

• Electrostatic field:

  Electrostatic field (in N/C)added to the world, apply force on object if and only if it has non zero charge and it is inside bounds of field.

• Magnetic field:

  The magnetic lorentz force on an object is calculated asForce = charge x speed x magnetic field  and is perpendicular to the velocity

• Buoyancy and drag:

  Buoyancy can be added to a region representing hypothetical liquid in that region. The density and viscosity of liquid can be changed while adding/editing field.

Gui Widgets

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From SimPhy 3.0 onwards there is support of widgets that can be added to simulations. few of widgets are just for information purpose (like label and text widget), while other widgets respond to event by associating scripts with them(like button, slider etc).

Simphy supports follwing widgets

• Non Scriptable Widgets (label, Text and Graphs)
• Button
• Slider
• List and Combo
• Timer

Analyse and Visualise

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Any Simulation created can be analysed to learn actual physics behind it in following ways

• Draw Free Body diagram showing all forces on body (with their values) is extremely useful in understanding dynamics of body
• Plot variation of velocity, position, angular speed etc of body, select camera tool(by clicking over it) and press over the object.
• View Simulation in Frame of Object Camera will have its focus at center of mass of selected object(s) and hence center of mass of selection will always seem to be at rest.
• Attach tracer to any point on body to view/study path of object.

Mouse Gestures

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SimPHY supports many Moue based gestures to draw objects and joints and to edit/delete them without need of switching tools.

Few of them are

• Selection gestures

  Individual body or joint can be selected by simply clicking over them. Selection clears when clicked somewhere else.

• Object Creation gestures

  If drawn figure is closed curve it will be transformed to disc, box triangle or polygon

• Joint Gestures

  Joining 2 bodies with straight or zigzag curve creates distance or spiring joint etc.

• Other Gestures

  Simply draw a vertical line to pause or resume simulation, draw line over selected objects to delete them and many more

Scripting

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SimPhy allows to write Javascript code corresponding to events associated with world, such as

Scripting on World Events

• Start Stop or update of simulation
• Keyboard Events
• Mouse Events

Scripting on Widget Events

• Click of Button
• Change of Slider Value
• Timer fire

Advanced features

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For finer control over simuation SimPHY supports some advanced features:

• Material properties for body: Each body can be modified to simulate materials like rubber, stone wood etc by changing friction, restitution or choosing from predefined set of objects
• Key Controllars for Body: Motion of can be controlled by binding keyboard key to it, on pressing the key body can be accelerated or rotated.
• Collision filtering It is used to only allow a category of bodies to collide with another category.
• Setting Html text to BodyThe body can display text in HTML format, which is extremely useful to display information in simulation in eye catching/fancy way.

Animations

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Now we can create frame by frame animations and associate them to bodies in simphy by simple code

body.setAnimation(world.getAnimation("animation name"));

Or you can display animation on screen by function

world.playAnimation("animation name");

Actions

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Each body now can have a action, which is updated each frame by the bodies act method. Many types of actions are included which can be instantiated, configured, and added to an actor. When the action is complete, it will automatically be removed from the actor.

Animation actions modify various properties of your actor, such as location, rotation, scale and alpha. They are:

• FadeIn – changes alpha of your actor from actor’s current alpha to 1
• FadeOut – changes alpha of your actor from actor’s current alpha to 0
• FadeTo – changes alpha of your actor from actor’s current alpha to specific value
• MoveBy – moves your actor by specific amount
• MoveTo – moves your actor to specific location
• RotateBy – rotates your actor by specific angle
• RotateTo – rotates your actor to specific angle
• ScaleTo – scales your actor to specific scale factor

Composite actions combine multiple actions in one action, there are:

• Parallel – execute given actions in parallel – all actions at once
• Sequence – execute given actions in sequence – one after another

Other actions:

• Repeat – repeats given action n-times
• Forever – repeats given action forever
• Delay – delays execution of given action for specific amount of time
• Remove – removes given Actor from stage

var rotate =actions.rotateTo(60,0.5f); //rotate Actor to angle 60 in 0.5 s

Example of creating more complex action sequence:

body.setAction(actions.sequence(actions.moveTo(10, 2), actions.delay(0.5f), actions.rotateTo(180,5)));