Connect Manipulators to the Show Manipulator Tool

Writing a Manipulator to Work with the Show Manipulator Tool

The first step when creating a manipulator that works with the Show Manipulator Tool for a node is to pick a name for the manipulator that corresponds to the node type name. To determine the name of the manipulator, take the name of the node and append Manip to the end of the node name. For example, the Show Manip for footPrintLocator is footPrintLocatorManip.

plugin.registerNode("footPrintLocator", // name of node
                    footPrintLocator::id,
                    &footPrintLocator::creator,
                    &footPrintLocator::initialize,
                    MPxNode::kLocatorNode);
plugin.registerNode("footPrintLocatorManip", // name of manip
                    footPrintLocatorManip::id,
                    &footPrintLocatorManip::creator,
                    &footPrintLocatorManip::initialize,
                    MPxNode::kManipContainer);

The second step is to have the initialize method of the node call MPxManipContainer::addToManipConnectTable(). For example, in the footPrintLocator::initialize() method:

MStatus footPrintLocator::initialize()
{
    ...
    MPxManipContainer::addToManipConnectTable(id);
    ...
}

Where id is defined and declared as:

class footPrintLocator : public MPxLocatorNode
{
    ...
    public:
        static MTypeId id;
};
MTypeId footPrintLocator::id(0x81101);

Adding the Manipulator to a Context

An alternative to invoking a manipulator by the Show Manipulator Tool is to invoke the manipulator from a user-defined context.

The MPxSelectionContext class has two methods to support the management of manipulators: addManipulator() and deleteManipulator().

In addition to using these two methods, MPxSelectionContext::toolOnSetup and MPxContext::toolOffCleanup must be overridden so that toolOnSetup adds a callback for manipulators, and toolOffCleanup removes the callback when the active list is modified.

The callback can be an updateManipulators() function which actually adds and deletes the manipulators.

For example:

MCallbackId id1;
void moveContext::toolOnSetup(MEvent &)
{
    ...
    id1 = ModelMessage::addCallback(
    MModelMessage::kActiveListModified,
    updateManipulators, this, &status);
    .... 
}
void moveContext::toolOffCleanup()
{
    ...
    status = MModelMessage::removeCallback(id1);
    ...
}
void updateManipulators(void * data)
{
    ...
    moveContext * ctxPtr = (moveContext *) data;
    ctxPtr->deleteManipulators();
    ...
    // for each object selected
    MString manipName("moveManip");
    MObject manipObject;
    ctxPtr->moveM = (moveManip *) 
        moveManip::newManipulator(manipName,
        manipObject);
    ...
    ctxPtr->addManipulator(manipObject);
    ...
    ctxPtr->moveM->connectToDependNode(dependNode);
    ...
}

Example Manipulators

Following are the manipulator examples that are available in the (devkit\plug-ins) folder of the Developer Kit installation: