INTRODUCTION TO MOTIONLINKS

A motionlink connects a source of position and orientation information to a target that will move corresponding to the data read from the source object. Normally the source object of a motionlink will be a sensor but it could also be path. The target types for a motionlink can be a viewpoint, movable, transform, or nodepath. The information for a motionlink is stored in a WTmotionlink object.

Motionlinks are extremely easy to create, enable, disable, and delete. While these are not the only functions that work with motionlinks they are the ones we will cover here.

Creating a new motionlink

WTmotionlink_new

Creates a new motionlink object and connects a target to a source of position/orientation information.

SYNTAX:

WTmotionlink *WTmotionlink_new(void *source, void *target, int SOURCE_TYPE, int TARGET_TYPE);

ARGUMENTS:

source -- The source of the position/orientation information this can be a pointer to a sensor or path.
target -- The target of the position/orientation information this can be a pointer to a viewpoint, movable, transform,
or nodepath
SOURCE_TYPE -- One of the predefined types WTSOURCE_SENSOR or WTSOURCE_PATH
TARGET_TYPE -- One of the predefined types WTTARGET_VIEWPOINT, WTTARGET_MOVABLE, WTTARGET_TRANSFORM, or WTTARGET_NODEPATH

RETURN TYPE:

A pointer to a type WTmotionlink

Assignment 11

project definition:

• Creates a universe with a bordered window in monoscopic mode..
• Create a cylinder that has a height of 40, a radius of 5, 12 tessellation lines, is single sided and gouraud shaded.
• Create a sphere with a radius of 10, 12 lat and long divisions, is single sided, and gouraud shaded.
• Create a movable geometry node for the cylinder whose parent is the root node.
• Create a movable geometry nodes for the sphere whose parent is the root node.
• Create and instance of the movable node containing the sphere as the 2^nd child of the root node
• Set the translation of the movable geometry containing the first sphere to (0,-20,0)
• Set the translation of the movable geometry containing the second sphere to (0,20,0)
• Set the rgb color of the sphere to red (255,0,0)
• Set the rgb color of the cylinder to blue (0,0,255)
• Set the rendering style of the sphere geometry to wireframe.
• Prebuild all the geometries
• Zooms the view in the window
• Create a task function that is associated with the node containing the cylinder. The function should rotate the cylinder in its parent reference frame around the Y axis by 15 degrees each time through the simulation loop.
• Add the mouse to the universe as a sensor
• Attach the mouse to the viewpoint using a motionlink
• Create an action function that allows the user to:
  • press q to quit
  • press p to print the scene graph from the root node. (use WTnode print)
  • press i to obtain the extents, midpoint, and radius of each node
  • press I to obtain the extents, midpoint, and radius of each geometry.
  • Press t to translate the spheres and cylinder along their local X axis.
  • Create a function that uses the WTnode_translate function and takes as an argument the node to translate, three floating point values for the translation values, and the frame in which to translate.

Enabling as Disabling Motionlinks

Every motionlink as an enabled property that can be set to TRUE or FALSE. By disabling the motionlink the target is no longer update with the source information. This is an easy way for the user to remove a link and still keep it around for future use. A good example of this would be toggling the mouse between navigation mode and pick mode.

WTmotionlink_enable

Enables and disables a motionlink

SYNTAX:

void WTmotionlink_enable(WTmotionlink *link, FLAG enabled);

ARGUMENTS:

link -- The motionlink in question
enabled -- If this argument is TRUE then the link is enables if FALSE then the motionlink is disabled

RETURN TYPE:

void

Assignment 12

project definition:

• Creates a universe with a bordered window in monoscopic mode..
• Create a cylinder that has a height of 40, a radius of 5, 12 tessellation lines, is single sided and gouraud shaded.
• Create a sphere with a radius of 10, 12 lat and long divisions, is single sided, and gouraud shaded.
• Create a movable geometry node for the cylinder whose parent is the root node.
• Create a movable geometry nodes for the sphere whose parent is the root node.
• Create and instance of the movable node containing the sphere as the 2^nd child of the root node
• Set the translation of the movable geometry containing the first sphere to (0,-20,0)
• Set the translation of the movable geometry containing the second sphere to (0,20,0)
• Set the rgb color of the sphere to red (255,0,0)
• Set the rgb color of the cylinder to blue (0,0,255)
• Set the rendering style of the sphere geometry to wireframe.
• Prebuild all the geometries
• Zooms the view in the window
• Create a task function that is associated with the node containing the cylinder. The function should rotate the cylinder in its parent reference frame around the Y axis by 15 degrees each time through the simulation loop.
• Add the mouse to the universe as a sensor
• Attach the mouse to the viewpoint using a motionlink
• Create an action function that allows the user to:
  • press q to quit
  • press p to print the scene graph from the root node. (use WTnode print)
  • press i to obtain the extents, midpoint, and radius of each node
  • press I to obtain the extents, midpoint, and radius of each geometry.
  • press t to translate the spheres and cylinder along their local X axis.
  • Create a function that uses the WTnode_translate function and takes as an argument the node to translate, three floating point values for the translation values, and the frame in which to translate.
  • Press f on the keyboard to toggle the motionlink from enabled to disabled and disabled to enabled. You should also print a message to the user indicating weather they are in pick or navigation mode.