Set Up a Control Node

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1. 1. What is a control node?

2. 2. Types

3. 3. Usage

4. 4. Advanced stuff

   DSP_CONFIG { DATA { SCENE_LOAD { CONTROLS { # node(name); control(name); control_xyz(x,y,z); control_pyr(p,y,r); xyz(x,y,z); pyr(p,y,r); order( PYR ); parent( node_name ); attrib(INHIBIT_CONTROL);

               # Examples 
               node(PROX_OPS); control_xyz(621.0,0,978.5); control_pyr(-90,0,0); control(NODE1_PAS); parent(ORBITER_STRUCTURE);
               node(EV1_SIGNAL); control(EV1_antenna); parent(ORBITER_STRUCTURE);
               node(EV2_SIGNAL); control(EV2_antenna); parent(ORBITER_STRUCTURE);
           }
   

   ...

1.  What is a control node?

Control nodes are nodes that can be used to have node information output in a different frame, OR allow nodes to be driven in a different frame.

2.  Types

There are two types of control nodes: passive and active.

• Passive control nodes are simply an alias for the node in a different frame and are output only
• Active control nodes drive a node in the NULL frame using numbers that are auto-calculated from input numbers in the control node in its own frame

3.  Usage

• control field is the node being controlled (active control) or monitored (passive control)
• control node is active (not passive) only if the node it controls has a parent of NULL Note: If the control node's parent is erroneously set to NULL at startup, you can add 'attrib(INHIBIT_CONTROL);' to the node being controlled to make sure it will not be driven.

For example, if the user wanted to add a frame to see the position of node A in the frame of node C even though node A is actually linked to some other node then the user could define a control node B that controls node A in the frame of node C. A user would then be able to monitor node B which would be updated to reflect the position of node A relative to node C in real time as long as node A has a non-NULL parent, if the parent of node A is/becomes NULL then node A will be automatically driven in the NULL frame as if it where a child of node B in the frame of node C.

CONTROLS
 {
    node(B); control(A); parent(C);
 }

Since node A has a parent that is non-NULL (presumably), then this control node would be a passive control node and would be for output data only (a monitor node so to speak).

But, if node A has it's parent changed to NULL, the control node would become active, making it as if node A was now a child of node B with zero offset. If you want to have an offset between controllee and control node, then you can use the control_xyz and control_pyr parameters shown above.

The active control node allows the user to drive a node in a different frame, rather than just see the data. Meaning, instead of the data in the control node being output by the visuals (in the cae of a passive control node), the control node would now accept input data to drive the controllee in the control nodes frame.

4.  Advanced stuff

• if multiple control nodes are defined for a single node, then the last one defined will, by default, be the active one

• to change the active control node during runtime, the user can set the parent of the node being controlled to the new control node. EDGE will see the new parent is a control node, change it to be the active, and then relink the node back to NULL automatically.

• The algorithm to figure out the source of the transform to be used in the visuals is below

  normal node dependency_is : parent

            modified controllee
                   dependency_is : parent
                   if( parent is one of its passive controllers )
                          parent_becomes : passive_control
                          passive_contorl becomes active controller
  
                   if( INHIBIT_CONTROL_ATTRIB not set )
                          parent_becomes : null
  
            non-modified controllee
                   if( INHIBIT_CONTROL_ATTRIB not set )
                          dependency_is : active_control_node
                   else
                          dependency_is : parent
  
            active control with modified controllee
                   dependency_is : controllee
  
            active control with non-modified controllee
                   if( INHIBIT_CONTROL_ATTRIB not set )
                          dependency_is : parent
                   else
                          dependency_is : controlee
  
            passive control
                   dependency_is : controlee
  
            Use the above rules to build a dependency array (secondary parent_id)
  

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