Activities/Physics: Difference between revisions

Line 93:

|'''Hints and tips''': Single clicking (no drag) with the circle, triangle or box tool, will add a default sized shape. Once you have used a shape tool, it remembers the last shape you made with it, a single click will add a clone of that last shape.

|}

== Did you know? ==

There is a Plugin for [[Activities/TurtleArt|Turtle Blocks]] that lets you create projects for the Physics Activity:

[[File:Physics pallette.jpg]]

Use these blocks to create objects that are added to the bodylist and jointlist of a Box2d database used by the Physics Activity. Objects are positioned by the turtle x,y and colored based on the current pen attributes. From left to right:

* density: set the object density (0 is light; 1 is heavy)

* friction: set the object friction (0 is slippery; 1 is sticky)

* bounciness: set the object restitution (0 is rigid; 1 is bouncy)

* start polygon: use the current turtle x,y position to specify the first vertex of a polygon

* add point: use the current turtle x,y position to add a vertex to a polygon

* end polygon: use the current turtle x,y position to specify the last vertex of a polygon

* end filled polygon: use the current turtle x,y position to specify the last vertex of a ''filled'' polygon

: '''Note:''' The polygon must be 'normal', e.g., no crossed lines; no holes. Since Box2d does not support concave polygons, all polygons are converted to triangles (triangulation). (In Turtle Blocks, these triangles are shown by slight variations in color.)

* triangle: add a triangle object at the current turtle x,y position

* circle: add a circle object at the current turtle x,y position

* rectangle: add a rectangle object at the current turtle x,y position

* gear: add a gear object at the current turtle x,y position with the number of teeth as the argument

* gear radius: returns the radius of a gear with the number of teeth as the argument (useful for positioning gears)

* motor: add a motor at the current turtle x,y position (attached to the object at this position)

* pin: add a pin at the current turtle x,y position (attached to the object at this position) to prevent movement

* pen: add a pen at the current turtle x,y position (attached to the object at this position) to trace motion

* joint: add a joint between the object at the current turtle x,y position and the object at x, y

* save as Physics project: save the current bodylist and jointlist as a Physics project in the Journal

'''Note:''' The current model is cleared whenever the Erase button is pressed or a Clean block is run.

===== Example =====

A simple gear and motor generated in Turtle Art:

[[File:TAGearTA.png|300px]]

[[File:TAGear.png|300px]]

'''For Turtle Blocks versions 107 - 183'''

[[File:TAgear.ta]] [[File:Gear.physics]]

'''For Turtle Blocks verisons 184 - '''

[http://people.sugarlabs.org/walter/physics-plugin.tar.gz]

'''A chain'''

[[File:Chain.png|300px]]

Turtle Blocks project file: [http://people.sugarlabs.org/walter/chain.tb]

===Downloads===

[[File:Physics-plugin.tar.gz]] Physics plugin

[http://github.com/walterbender/physics-plugin git repository]

= Development =

@@ Line 93: / Line 93: @@
 |'''Hints and tips''': Single clicking (no drag) with the circle, triangle or box tool, will add a default sized shape. Once you have used a shape tool, it remembers the last shape you made with it, a single click will add a clone of that last shape.
 |}
+== Did you know? ==
+There is a Plugin for [[Activities/TurtleArt|Turtle Blocks]] that lets you create projects for the Physics Activity:
+[[File:Physics pallette.jpg]]
+Use these blocks to create objects that are added to the bodylist and jointlist of a Box2d database used by the Physics Activity. Objects are positioned by the turtle x,y and colored based on the current pen attributes. From left to right:
+* density: set the object density (0 is light; 1 is heavy)
+* friction: set the object friction (0 is slippery; 1 is sticky)
+* bounciness: set the object restitution (0 is rigid; 1 is bouncy)
+* start polygon: use the current turtle x,y position to specify the first vertex of a polygon
+* add point: use the current turtle x,y position to add a vertex to a polygon
+* end polygon: use the current turtle x,y position to specify the last vertex of a polygon
+* end filled polygon: use the current turtle x,y position to specify the last vertex of a ''filled'' polygon
+: '''Note:''' The polygon must be 'normal', e.g., no crossed lines; no holes. Since Box2d does not support concave polygons, all polygons are converted to triangles (triangulation). (In Turtle Blocks, these triangles are shown by slight variations in color.)
+* triangle: add a triangle object at the current turtle x,y position
+* circle: add a circle object at the current turtle x,y position
+* rectangle: add a rectangle object at the current turtle x,y position
+* gear: add a gear object at the current turtle x,y position with the number of teeth as the argument
+* gear radius: returns the radius of a gear with the number of teeth as the argument (useful for positioning gears)
+* motor: add a motor at the current turtle x,y position (attached to the object at this position)
+* pin: add a pin at the current turtle x,y position (attached to the object at this position) to prevent movement
+* pen: add a pen at the current turtle x,y position (attached to the object at this position) to trace motion
+* joint: add a joint between the object at the current turtle x,y position and the object at x, y
+* save as Physics project: save the current bodylist and jointlist as a Physics project in the Journal
+'''Note:''' The current model is cleared whenever the Erase button is pressed or a Clean block is run.
+===== Example =====
+A simple gear and motor generated in Turtle Art:
+[[File:TAGearTA.png|300px]]
+[[File:TAGear.png|300px]]
+'''For Turtle Blocks versions 107 - 183'''
+[[File:TAgear.ta]] [[File:Gear.physics]]
+'''For Turtle Blocks verisons 184 - '''
+[http://people.sugarlabs.org/walter/physics-plugin.tar.gz]
+'''A chain'''
+[[File:Chain.png|300px]]
+Turtle Blocks project file: [http://people.sugarlabs.org/walter/chain.tb]
+===Downloads===
+[[File:Physics-plugin.tar.gz]] Physics plugin
+[http://github.com/walterbender/physics-plugin git repository]
 = Development =