Maya-SDK/cpp_ref/build_rotation_node_2build_rotation_node_8cpp-example.html

//-

// ==========================================================================

// 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.

// ==========================================================================

//+


// DESCRIPTION:

//

// Produces the dependency graph node "buildRotation".

//

// This example demonstrates performing a linear algebra calculation based on inputs and outputting the result.

//

// The node takes an up vector and a forward vector as inputs.

// It outputs the rotation that takes the y-axis and z-axis and rotates them to be the up and forward vectors respectively.

//

// A sample use of this node is to align an object to another surface based on a normal and a tangent vector.

// This example uses the "pointOnSurfaceNode", which is a standard node provided with Maya.

//

// sphere -radius 4;

// cone -ax 0 1 0;

// createNode pointOnSurfaceInfo;

// connectAttr nurbsSphereShape1.worldSpace pointOnSurfaceInfo1.inputSurface;

// connectAttr pointOnSurfaceInfo1.position nurbsCone1.translate;

// setAttr pointOnSurfaceInfo1.u 0.01;

// setAttr pointOnSurfaceInfo1.v 0.01;

//

// At this point, the cone is constrained to a point on the surface of the sphere.

// As the "u" and "v" attributes of the "pointOnSurfaceNode" are changed, the cone will move around the surface.

// The next step is to align the cone so that the tip points in the direction of the normal.

// The "buildRotation" node is used to do this.

//

// createNode buildRotation;

// connectAttr pointOnSurfaceInfo1.normal buildRotation1.up;

// connectAttr pointOnSurfaceInfo1.tangentU buildRotation1.forward;

// connectAttr buildRotation1.rotate nurbsCone1.rotate;

//

// Now, the cone will be constrained to the surface of the sphere and will also be aligned with the normal of the sphere at the point of constraint.

//


#include <string.h>

#include <maya/MIOStream.h>

#include <math.h>


#include <maya/MPxNode.h>


#include <maya/MFnNumericAttribute.h>

#include <maya/MFnMatrixAttribute.h>

#include <maya/MFnUnitAttribute.h>

#include <maya/MFnEnumAttribute.h>

#include <maya/MFnPlugin.h>


#include <maya/MString.h>

#include <maya/MTypeId.h>

#include <maya/MPlug.h>

#include <maya/MVector.h>

#include <maya/MMatrix.h>

#include <maya/MTransformationMatrix.h>

#include <maya/MDataBlock.h>

#include <maya/MDataHandle.h>


#define EPSILON             0.001

#define ROTATE_ORDER_XYZ    0

#define ROTATE_ORDER_YZX    1

#define ROTATE_ORDER_ZXY    2

#define ROTATE_ORDER_XZY    3

#define ROTATE_ORDER_YXZ    4

#define ROTATE_ORDER_ZYX    5


#define McheckErr(stat,msg)         \

    if ( MS::kSuccess != stat ) {   \

        cerr << msg;                \

        return MS::kFailure;        \

    }


class buildRotation : public MPxNode

{

public:

                        buildRotation();

                    ~buildRotation() override;


    MStatus     compute( const MPlug& plug, MDataBlock& data ) override;


    static  void*       creator();

    static  MStatus     initialize();


public:


    // Inputs

    static  MObject     up;           // Up vector

    static  MObject         upX;

    static  MObject         upY;

    static  MObject         upZ;

    static  MObject     forward;      // Front Vector

    static  MObject         forwardX;

    static  MObject         forwardY;

    static  MObject         forwardZ;

    static  MObject     rotateOrder;  // Desired rotation order


    // Outputs

    static  MObject     rotate;       // Rotation as a 3 Double

    static  MObject         rotateX;

    static  MObject         rotateY;

    static  MObject         rotateZ;

    static  MObject     rotateMatrix; // Rotation as a matrix


    static  MTypeId     id;

};


MTypeId     buildRotation::id( 0x80004 );

MObject     buildRotation::up;

MObject     buildRotation::upX;

MObject     buildRotation::upY;

MObject     buildRotation::upZ;

MObject     buildRotation::forward;

MObject     buildRotation::forwardX;

MObject     buildRotation::forwardY;

MObject     buildRotation::forwardZ;

MObject     buildRotation::rotateOrder;

MObject     buildRotation::rotate;

MObject     buildRotation::rotateX;

MObject     buildRotation::rotateY;

MObject     buildRotation::rotateZ;

MObject     buildRotation::rotateMatrix;


buildRotation::buildRotation() {}

buildRotation::~buildRotation() {}


MStatus buildRotation::compute( const MPlug& plug, MDataBlock& data )

{


    MStatus returnStatus;


    if ((plug == rotate) || (plug.parent() == rotate) || (plug == rotateMatrix)) {

        MDataHandle upData = data.inputValue( up, &returnStatus );

        McheckErr(returnStatus,"ERROR getting up vector data");


        MDataHandle forwardData = data.inputValue( forward, &returnStatus );

        McheckErr(returnStatus,"ERROR getting forward vector data");


        MVector up = upData.asVector();

        MVector forward = forwardData.asVector();


        // Make sure that the up and forward vectors are orthogonal

        //

        if ( fabs( up * forward ) > EPSILON ) {

            // Non-zero dot product

            //

            MVector orthoVec = up ^ forward;

            MVector newForward = orthoVec ^ up;

            if ( forward * newForward < 0.0 ) {

                // Reverse the vector

                //

                newForward *= -1.0;

            }

            forward = newForward;

        }


        // Calculate the rotation required to align the y-axis with the up

        // vector

        //

        MTransformationMatrix firstRot;

        MVector rotAxis = MVector::yAxis ^ up;

        rotAxis.normalize();

        firstRot.setToRotationAxis( rotAxis, MVector::yAxis.angle( up ) );


        // Calculate the second rotation required to align the forward vector

        //

        MTransformationMatrix secondRot;

        MVector transformedForward = firstRot.asMatrix() * forward;

        transformedForward.normalize();

        double angle = transformedForward.angle( MVector::zAxis );

        if ( transformedForward.x < 0.0 ) {

            // Compensate for the fact that the angle method returns

            // the absolute value

            //

            angle *= -1.0;

        }

        secondRot.setToRotationAxis( up, angle );


        // Get the requested rotation order

        //

        MDataHandle orderHandle = data.inputValue( rotateOrder );

        short order = orderHandle.asShort();

        MTransformationMatrix::RotationOrder rotOrder;

        switch ( order ) {

            case ROTATE_ORDER_XYZ:

                rotOrder = MTransformationMatrix::kXYZ; break;

            case ROTATE_ORDER_YZX:

                rotOrder = MTransformationMatrix::kYZX; break;

            case ROTATE_ORDER_ZXY:

                rotOrder = MTransformationMatrix::kZXY; break;

            case ROTATE_ORDER_XZY:

                rotOrder = MTransformationMatrix::kXZY; break;

            case ROTATE_ORDER_YXZ:

                rotOrder = MTransformationMatrix::kYXZ; break;

            case ROTATE_ORDER_ZYX:

                rotOrder = MTransformationMatrix::kZYX; break;

            default:

                rotOrder = MTransformationMatrix::kInvalid; break;

        }


        MTransformationMatrix result = firstRot.asMatrix() * secondRot.asMatrix();

        result.reorderRotation( rotOrder );


        double rotation[3];

        result.getRotation( rotation, rotOrder);


        MDataHandle outputRot = data.outputValue( rotate );

        outputRot.set( rotation[0], rotation[1], rotation[2] );

        outputRot.setClean();


        MDataHandle outputMatrix = data.outputValue( rotateMatrix );

        outputMatrix.set( result.asMatrix() );

        outputMatrix.setClean();

    } else

        return MS::kUnknownParameter;


    return MS::kSuccess;

}


void* buildRotation::creator()

{

    return new buildRotation();

}


MStatus buildRotation::initialize()

{

    MFnNumericAttribute nAttr;

    MFnMatrixAttribute  mAttr;

    MFnUnitAttribute    uAttr;

    MFnEnumAttribute    eAttr;

    MStatus             stat;


    // Set up inputs

    //

    upX = nAttr.create( "upX", "ux", MFnNumericData::kDouble );

        nAttr.setStorable(false);

    upY = nAttr.create( "upY", "uy", MFnNumericData::kDouble );

        nAttr.setStorable(false);

    upZ = nAttr.create( "upZ", "uz", MFnNumericData::kDouble );

        nAttr.setStorable(false);

    up = nAttr.create( "up", "u", upX, upY, upZ );

        nAttr.setDefault( 0.0, 1.0, 0.0 );

        nAttr.setStorable(false);


    forwardX = nAttr.create( "forwardX", "fx", MFnNumericData::kDouble, 0.0 );

        nAttr.setStorable(false);

    forwardY = nAttr.create( "forwardY", "fy", MFnNumericData::kDouble, 0.0 );

        nAttr.setStorable(false);

    forwardZ = nAttr.create( "forwardZ", "fz", MFnNumericData::kDouble, 1.0 );

        nAttr.setStorable(false);

    forward = nAttr.create( "forward", "f", forwardX, forwardY, forwardZ );

        nAttr.setDefault( 0.0, 0.0, 1.0 );

        nAttr.setStorable(false);


    rotateOrder = eAttr.create( "rotateOrder", "ro", ROTATE_ORDER_XYZ);

        eAttr.addField("xyz", ROTATE_ORDER_XYZ);

        eAttr.addField("yzx", ROTATE_ORDER_YZX);

        eAttr.addField("zxy", ROTATE_ORDER_ZXY);

        eAttr.addField("xzy", ROTATE_ORDER_XZY);

        eAttr.addField("yxz", ROTATE_ORDER_YXZ);

        eAttr.addField("zyx", ROTATE_ORDER_ZYX);

        eAttr.setStorable(false);


    // Set up outputs

    //

    rotateX = uAttr.create( "rotateX", "rx", MFnUnitAttribute::kAngle, 0.0 );

        nAttr.setStorable(false);

    rotateY = uAttr.create( "rotateY", "ry", MFnUnitAttribute::kAngle, 0.0 );

        nAttr.setStorable(false);

    rotateZ = uAttr.create( "rotateZ", "rz", MFnUnitAttribute::kAngle, 0.0 );

        nAttr.setStorable(false);

    rotate = nAttr.create( "rotate", "r", rotateX, rotateY, rotateZ );

        nAttr.setStorable(false);


    rotateMatrix = mAttr.create( "rotateMatrix", "rm" );

        nAttr.setStorable(false);

        nAttr.setConnectable(true);


    stat = addAttribute( up );

        if (!stat) { stat.perror("addAttribute"); return stat;}

    stat = addAttribute( forward );

        if (!stat) { stat.perror("addAttribute"); return stat;}

    stat = addAttribute( rotate );

        if (!stat) { stat.perror("addAttribute"); return stat;}

    stat = addAttribute( rotateOrder );

        if (!stat) { stat.perror("addAttribute"); return stat;}

    stat = addAttribute( rotateMatrix );

        if (!stat) { stat.perror("addAttribute"); return stat;}


    stat = attributeAffects( up, rotate );

        if (!stat) { stat.perror("attributeAffects"); return stat;}

    stat = attributeAffects( up, rotateMatrix );

        if (!stat) { stat.perror("attributeAffects"); return stat;}

    stat = attributeAffects( forward, rotate );

        if (!stat) { stat.perror("attributeAffects"); return stat;}

    stat = attributeAffects( forward, rotateMatrix );

        if (!stat) { stat.perror("attributeAffects"); return stat;}

    stat = attributeAffects( rotateOrder, rotate );

        if (!stat) { stat.perror("attributeAffects"); return stat;}

    stat = attributeAffects( rotateOrder, rotateMatrix );

        if (!stat) { stat.perror("attributeAffects"); return stat;}


    return MS::kSuccess;

}


MStatus initializePlugin( MObject obj )

{

    MStatus   status;

    MFnPlugin plugin( obj, PLUGIN_COMPANY, "3.0", "Any");


    status = plugin.registerNode( "buildRotation", buildRotation::id,

                         buildRotation::creator, buildRotation::initialize );

    if (!status) {

        status.perror("registerNode");

        return status;

    }


    return status;

}


MStatus uninitializePlugin( MObject obj)

{

    MStatus   status;

    MFnPlugin plugin( obj );


    status = plugin.deregisterNode( buildRotation::id );

    if (!status) {

        status.perror("deregisterNode");

        return status;

    }


    return status;

}