surfaceTwist.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.
// ==========================================================================
//+

#include <maya/MStatus.h>
#include <maya/MObject.h>
#include <maya/MString.h> 
#include <maya/MArgList.h>
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MItSelectionList.h>
#include <maya/MItSurfaceCV.h>
#include <maya/MItMeshVertex.h>
#include <maya/MPoint.h>
#include <maya/MVector.h>
#include <maya/MMatrix.h>
#include <maya/MDagPath.h>
#include <maya/MFileIO.h>
#include <maya/MLibrary.h>
#include <maya/MIOStream.h>
#include <math.h> 

MStatus twistSurf();

int main(int /*argc*/, char **argv)
{
        MStatus stat;

        stat = MLibrary::initialize (argv[0]);
        if (!stat) {
                stat.perror("MLibrary::initialize");
                return 1;
        }

        MString fileName("surf1.ma");

        cout << ">>>> Attempting to load surf1.ma <<<<\n";
        stat = MFileIO::open(fileName, "mayaAscii", true);
        if ( stat )
                cout << ">>>> Load Successfull <<<<\n";
        else {
                cout << ">>>> Load Failed <<<<\n";
                stat.perror("MFileIO::open");
                return 1;
        }

        stat = twistSurf();
        if (!stat)
                return 1;

        cout << ">>>> Attempting save as surf2.ma <<<<\n";
        stat = MFileIO::exportAll("surf2.ma", "mayaAscii");
        if (stat)
                cout << ">>>> Save Successfull <<<<\n";
        else {
                cout << ">>>> Save Failed <<<<\n";
                stat.perror("MFileIO::exportAll");
        }

        MLibrary::cleanup();
        return 0;
}

#define NUM_SPANS        30
#define WIDTH            10.0
#define VERTICAL_SCALING 4.0

static MStatus twistNurbsSurface(MDagPath& objectPath, MObject& component)
{
        MStatus status;

        MPoint  center;
        MVector toCenter( -center.x, 0.0, -center.y );
        double  rotFactor = 0.5;

        // We have a nurbs surface or component
        //
        MItSurfaceCV cvIter( objectPath, component, true, &status );

        if ( status ) {
                // We successfully created a nurbs surface iterator
                //
                for ( ; !cvIter.isDone(); cvIter.nextRow() ) {
                        for ( ; !cvIter.isRowDone(); cvIter.next() ) {
                                // Get the location of the CV
                                //
                                MPoint pnt = cvIter.position( MSpace::kWorld );
                                pnt = pnt + toCenter;
                                // Calculate rotation in radians about the y-axis
                                //
                                double rotation = pnt.y * rotFactor;
                                MMatrix rotMatrix;
                                // Set matrix to a rotation about the y axis
                                //
                                rotMatrix(0,0) = cos( rotation );
                                rotMatrix(0,2) = sin( rotation );
                                rotMatrix(2,0) = -sin( rotation );
                                rotMatrix(2,2) = cos( rotation );
                                pnt = ( pnt * rotMatrix ) - toCenter;

                                status = cvIter.setPosition( pnt, MSpace::kWorld );
                                if ( !status ) {
                                        status.perror("MItSurfaceCV::setPosition");
                                        break;
                                }
                        }
                }
                // Tell maya to redraw the surface with all of our changes
                //
                cvIter.updateSurface();
        } else
                status.perror("MItSurfaceCV::MItSurfaceCV");
        return status;
}

static MStatus twistPolygon(MDagPath& objectPath, MObject& component)
{
        MStatus status;

        MPoint  center;
        MVector toCenter( -center.x, 0.0, -center.y );
        double  rotFactor = 0.5;

        MItMeshVertex vertIter( objectPath, component, &status );

        if ( status ) {
                // We successfully created a polygon vertex iterator
                //

                for ( ; !vertIter.isDone(); vertIter.next() ) {
                        // Get the location of the vertex
                        //
                        MPoint pnt = vertIter.position( MSpace::kWorld );
                        pnt = pnt + toCenter;
                        // Calculate rotation in radians about the y-axis
                        //
                        double rotation = pnt.y * rotFactor;
                        MMatrix rotMatrix;
                        // Set matrix to a rotation about the y axis
                        //
                        rotMatrix(0,0) = cos( rotation );
                        rotMatrix(0,2) = sin( rotation );
                        rotMatrix(2,0) = -sin( rotation );
                        rotMatrix(2,2) = cos( rotation );
                        pnt = ( pnt * rotMatrix ) - toCenter;

                        status = vertIter.setPosition( pnt, MSpace::kWorld );
                        if ( !status ) {
                                status.perror("MItMeshVertex::MItMeshVertex");
                                break;
                        }
                }
                // Tell maya to redraw the surface with all of our changes
                //
                vertIter.updateSurface();
        } else
                status.perror("MItSurfaceCV::MItSurfaceCV");
        return status;
}

MStatus twistSurf()
{
        MStatus status;

        cout << ">>>> Start twist routine <<<<" << endl;

        MString surface1("surface1");
        MGlobal::selectByName(surface1, MGlobal::kReplaceList);

        // Create an iterator for the active selection list
        //
        MSelectionList slist;
        MGlobal::getActiveSelectionList( slist );
        MItSelectionList iter( slist );

        if (iter.isDone()) {
                cerr << "Nothing selected\n";
                return MS::kFailure;
        }

        MDagPath objectPath;
        MObject component;

        for ( ; !iter.isDone(); iter.next() ) {
                status = iter.getDagPath( objectPath, component );

                if (objectPath.hasFn(MFn::kNurbsSurface))
                        status = twistNurbsSurface(objectPath, component);
                else if (objectPath.hasFn(MFn::kMesh))
                        status = twistPolygon(objectPath, component);
                else {
                        cerr << "Selected object is not a NURBS surface or a polygon\n";
                        return MS::kFailure;
                }
        }

        if ( status ) {
                cout << ">>>> Twist Successfull <<<<\n";
        } else {
                cout << ">>>> Twist Failed <<<<\n";
        }

        return status;
}