closestPointCmd.cpp

//-
// ==========================================================================
// Copyright 1995,2006,2008 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+


// MAYA HEADERS
#include <maya/MFnPlugin.h>
#include <maya/MDagPath.h>
#include <maya/MFnMesh.h>
#include <maya/MMeshIntersector.h>
#include <maya/MItSelectionList.h>
#include <maya/MItMeshPolygon.h>
#include <maya/MObject.h>
#include <maya/MSelectionList.h>
#include <maya/MArgList.h>
#include <maya/MFloatPoint.h>
#include <maya/MFnDependencyNode.h>
#include <maya/MFnPointLight.h>
#include <maya/MFloatPointArray.h>
#include <maya/MPxCommand.h>
#include <maya/MDGModifier.h>
#include <maya/MFnDagNode.h>
#include <maya/MDagPath.h>
#include <maya/MGlobal.h>
#include <maya/MIOStream.h>


#define MERR_CHK(status,msg) if ( !status ) { MGlobal::displayError(msg); } // cerr << msg << endl; }

//
//      PLUGIN DESCRIPTION
//      
//      This is an example of the closest point between a point light and a mesh.
//      
//
//      PLUGIN INSTRUCTIONS
//
//      - create a point light and a poly plane (mesh)
//      - run the command as such: closestPointCmd <pointLightName> <planeName>
//      - a sphere will be created at the closest point
//      
//      Use the following script to automatically display closest point on the mesh (assuming 
//      a point light and a mesh with the names used here exist):
//
//      global proc closestPointExample()
//      {
//              closestPointCmd pointLight1 pPlane1;
//              select -r pointLight1;
//      }
//
//      scriptJob -ac "pointLight1.tx" closestPointExample;
//      scriptJob -ac "pointLight1.ty" closestPointExample;
//      scriptJob -ac "pointLight1.tz" closestPointExample;
//
//      scriptJob -ac "pointLight1.rx" closestPointExample;
//      scriptJob -ac "pointLight1.ry" closestPointExample;
//      scriptJob -ac "pointLight1.rz" closestPointExample;
//

/*

// Alternatively use the following code to demonstrate
// the closest point
//

        loadPlugin closestPointCmd;

        file -f -new;
        defaultPointLight(1, 1,1,1, 0, 0, 0,0,0, 1);
        move -r 0 5 0 ;
        polyPlane -w 1 -h 1 -sx 10 -sy 10 -ax 0 1 0 -cuv 2 -ch 1;
        scale -r 10 10 10 ;
        closestPointCmd pointLight1 pPlane1;

        file -f -new;
        defaultPointLight(1, 1,1,1, 0, 0, 0,0,0, 1);
        move -r 2 5 0 ;
        polyPlane -w 1 -h 1 -sx 10 -sy 10 -ax 0 1 0 -cuv 2 -ch 1;
        scale -r 10 10 10 ;
        closestPointCmd pointLight1 pPlane1;
        select -cl;

        unloadPlugin closestPointCmd ;

*/




// MAIN CLASS FOR THE closestPointCmd COMMAND:
class closestPointCmd : public MPxCommand
{
        public:
                closestPointCmd();
                virtual ~closestPointCmd();
                static void* creator();
                bool isUndoable() const;
                MStatus doIt(const MArgList&);
                MStatus undoIt();

                void createDisplay( MPointOnMesh& info, MMatrix& matrix);
};



// CONSTRUCTOR:
closestPointCmd::closestPointCmd()
{
}



// DESTRUCTOR:
closestPointCmd::~closestPointCmd()
{
}



// FOR CREATING AN INSTANCE OF THIS COMMAND:
void* closestPointCmd::creator()
{
   return new closestPointCmd;
}



// MAKE THIS COMMAND NOT UNDOABLE:
bool closestPointCmd::isUndoable() const
{
   return false;
}

MStatus closestPointCmd::doIt(const MArgList& args)
// Description:
//              Determine the closest point between the point
//              light and the mesh.
//              If it does, it displays the point.
{
        MStatus status = MStatus::kSuccess;

        if (args.length() != 2) 
        {
                MGlobal::displayError("Need 2 items!");
                return MStatus::kFailure;
        }

        MSelectionList activeList;
        int i;
        for ( i = 0; i < 2; i++)
        {
                MString strCurrSelection;
                status = args.get(i, strCurrSelection);
                if (MStatus::kSuccess == status) activeList.add(strCurrSelection);
        }


        MItSelectionList iter(activeList);
        MFnPointLight fnLight;  
        MFnDagNode dagNod;
        MFnDependencyNode fnDN;
        MDagPath pathToMesh;

        float fX = 0;
        float fY = 0;
        float fZ = 0;

        for ( ; !iter.isDone(); iter.next() )
        {
                MObject tempObjectParent, tempObjectChild;
                iter.getDependNode(tempObjectParent);

                if (tempObjectParent.apiType() == MFn::kTransform)
                {
                        dagNod.setObject(tempObjectParent);
                        tempObjectChild = dagNod.child(0, &status);
                }

                // check what type of object is selected
                if (tempObjectChild.apiType() == MFn::kPointLight)
                {
                        MDagPath pathToLight;
                        MERR_CHK(MDagPath::getAPathTo(tempObjectParent, pathToLight), 
                                        "Couldn't get a path to the pointlight");
                        MERR_CHK(fnLight.setObject(pathToLight), "Failure on assigning light");

                        status = fnDN.setObject(tempObjectParent);

                        MPlug pTempPlug = fnDN.findPlug("translateX", &status);
                        if (MStatus::kSuccess == status)
                        {
                                pTempPlug.getValue(fX);
                        }

                        pTempPlug = fnDN.findPlug("translateY", &status);
                        if (MStatus::kSuccess == status)
                        {
                                pTempPlug.getValue(fY);
                        }

                        pTempPlug = fnDN.findPlug("translateZ", &status);
                        if (MStatus::kSuccess == status)
                        {
                                pTempPlug.getValue(fZ);
                        }       
                }
                else if (tempObjectChild.apiType() == MFn::kMesh)
                {
                        MERR_CHK(MDagPath::getAPathTo(tempObjectChild, pathToMesh), 
                                "Couldn't get a path to the pointlight");
                }
                else
                {
                        MGlobal::displayError("Need a pointlight and a mesh");
                        return MStatus::kFailure;
                }
        }

        MMeshIntersector intersector;
        MMatrix matrix = pathToMesh.inclusiveMatrix();
        MObject node = pathToMesh.node();
        status = intersector.create( node, matrix );
        if ( status )
        {
                MPoint point(fX,fY,fZ);
                MPointOnMesh pointInfo;
                cout << "Using point: " << point << endl;
                status = intersector.getClosestPoint( point, pointInfo );
                if ( status )
                {
                        createDisplay( pointInfo, matrix );
                }
                else
                {
                        MGlobal::displayError("Failed to get closest point");
                }
        }
        else
        {
                MGlobal::displayError("Failed to create intersector");
        }

        return status;
}

// UNDO THE COMMAND
MStatus closestPointCmd::undoIt()
{
        MStatus status;
        // undo not implemented
        return status;
}

void closestPointCmd::createDisplay( MPointOnMesh& info, MMatrix& matrix )
{
        MPoint worldPoint( info.getPoint() );
        worldPoint = worldPoint * matrix;
        MVector worldNormal( info.getNormal() );
        worldNormal = worldNormal * matrix;
        worldNormal.normalize();

        MString strCommandString = "string $strBall[] = `polySphere -r 0.5`;";
        strCommandString += "$strBallName = $strBall[0];";
        strCommandString += "setAttr ($strBallName + \".tx\") ";
        strCommandString += worldPoint.x;
        strCommandString += ";";
        strCommandString += "setAttr ($strBallName + \".ty\") ";
        strCommandString += worldPoint.y;
        strCommandString += ";";
        strCommandString += "setAttr ($strBallName + \".tz\") ";
        strCommandString += worldPoint.z;
        strCommandString += ";";

        MGlobal::executeCommand(strCommandString);

        // Other info
        cout << "Normal: " << worldNormal << " face id: " << info.faceIndex() << 
                " triangle id: " << info.triangleIndex() << endl;
}

// INITIALIZE THE PLUGIN:
MStatus initializePlugin(MObject obj)
{
        MStatus status;
        MFnPlugin plugin(obj, PLUGIN_COMPANY, "9.0", "Any");
        status = plugin.registerCommand("closestPointCmd", closestPointCmd::creator);
        return status;
}

// UNINITIALIZE THE PLUGIN:
MStatus uninitializePlugin(MObject obj)
{
        MStatus status;
        MFnPlugin plugin(obj);
        plugin.deregisterCommand("closestPointCmd");
        return status;
}