The Mt2D Control plug-in moves, scales, and rotates an object in 2D. Mt2D Control allows multi-finger 2D manipulation of an object in the scene. When the object is touched, it translates, rotates, and scales to keep the object underneath the user’s fingers as closely as possible. It moves within the screen relative 2D plane through the object’s center position defined by the objects orientation axes.

The container being manipulated must not have any local non-uniform scale. Mt2D Control forces y and z scale so they are equal to x scale when the object is touched. If non uniform scaling is required on object in the container, put the object’s container in a group and scale the parent. Or put Mt2D Control on an identity group and insert the object to be moved as a child container. All transformations set on the manipulated container’s parents are preserved.

This page contains the following topics and procedures:

Mt2D Control Configuration

• Momentum: Enables movement or rotation with momentum after the object is released.

  • Friction: Sets the amount of friction used when momentum is enabled.

• Lock Translation: Allows only rotation and scaling of the object.

• Lock Translation (Screen X): Prevents movement left-to-right on the screen.

• Lock Translation (Screen Y): Prevents movement up-and-down on the screen.

• Lock Translation (Object X): Prevents movement along the object’s local X axis.

• Lock Translation (Object Y): Prevents movement along the object’s local Y axis.

• Lock Rotation: Prevents rotation of the object.

• Lock Scale: Prevents resizing of the object.

• Limit Position: Limits the maximum and minimum position of the X and Y axis.

• Limit Rotation: Limits the maximum and minimum rotation of the X and Y axis.

• Limit Scale: Limits the maximum and minimum scale.

• Id: Gives additional context in the handler script, specify a string that identifies any notifications dispatched by Mt2D Control. This is often included as an argument for the event so a common script may handle events from a number of plug-ins.

• Set Shared Memory: Enables shared memory to be updated for the plug-in notifications when set to On.

  • Shared Memory Prefix: This sets a ‘prefix name’ to be prepended to the shared memory variables maintained by Mt2D Control notifications. For plug-ins that maintain multiple fields each field name has the prefix prepended to it followed by a dot ‘.’ so as to mimic member access to an object: if the prefix is ‘Obj’ the fields ‘field1’ and ‘field2’ would be identified with the strings ‘Obj.field1’ and ‘Obj.field2’. The shared memory field ‘Obj’ is also maintained and is simply an integer that is modified every time any of its ‘subfields’ is updated.

  • Shared Memory Type: Click either Global, Scene, or Distributed. This selects the shared memory area to update.

• Set Data Pool: Shows ‘you wish’ plug-in notifications to set a Data Pool variable.

  • Data Pool Variable: Shows the name of the Data Pool variable to have set.

• Active during screen wide telestration?: If the button to is to stay active when the screen-wide telestrator is on, set to On. The default is off, which means the button cannot be triggered when telestration is on.

• Hit Coordinate Type: Selects the Coordinate system to use. Click either Local, World or Screen. 

• Produce delta values, don’t move object: Does not alter transform of object with attached controller, but instead provide ‘deltas’ in the event notifications.

Events and Notifications

The events dispatched by Mt2D Control are:

OnGrab (when object is ‘grabbed’):

sub ONGrab (HitContainer as String, Id as String, HitPoint as Vertex, plug-inContainer as String, FirstChildContainer as String)

end sub

• HitContainer as String

• Id as String

• HitPoint as Vertex

• plug-inContainer as String

• FirstChildContainer as String
  OnGrabUpdate (when object is moved):

sub OnGrabUpdate (HitContainer as String, Id as String, Position as Vertex, Rotation as Vertex, Scale as Vertex, Pressure as Double)

end sub

• HitContainer as String

• Id as String

• Position as Vertex

• Rotation as Vertex

• Scale as Vertex

• Pressure as Double

OnAnimation (dispatched when post grab animation (momentum) is started, followed by OnGrabUpdates):

sub OnAnimation (HitContainer as String, Id as String)

end sub

• HitContainer as String

• Id as String
  OnGrabRelease (when both touch grab and momentum animation are complete):

sub OnAnimation (HitContainer as String, Id as String)

end sub

• HitContainer as String

• Id as String

The Shared Memory Field names updated are:

• HitContainer (the name of the container that was ‘hit’)

• Id (the user ID string entered in the notification interface)

• HitPoint

• plug-inContainer

• FirstChildContainer

• Position

• Rotation

• Scale

• Pressure

• State

The Data Pool structure updated is:

• Mt2D Control:

  • string HitContainer

  • string Id

  • string HitPoint

  • string plug-inContainer

  • string FirstChildContainer

  • string Position

  • string Rotation

  • string Scale

  • string Pressure

  • string State

To Create a Simple Scene with Mt2D Control

1. Create a new Scene.

2. Add a new group Container.

3. Add a Cube Geometry to the Container.

4. Add Mt2DControl to the Container.

5. Open the Scene in On Air. Move, rotate or scale the Cube with the touch input device.

6. Use the Mt2DControl editor to modify the plug-in behavior as required.