コード例 #1
0
void Example1_CurvesIn()
{
    IArchive archive( Alembic::AbcCoreHDF5::ReadArchive(), "curves1.abc" );
    std::cout << "Reading: " << archive.getName() << std::endl;

    std::cout <<"constructing curves" << std::endl;
    ICurves myCurves( IObject( archive, kTop) , "reallly_long_curves_name");
    std::cout << "getting schema" << std::endl;
    ICurvesSchema &curves = myCurves.getSchema();
    std::cout << "done getting schema" << std::endl;

    // get the samples from the curves
    ICurvesSchema::Sample curvesSample;
    curves.get( curvesSample );

    // test the bounding box
    TESTING_ASSERT( curvesSample.getSelfBounds().min == V3d( -1.0, -1.0, -1.0 ) );
    std::cout << "bounds max " << curvesSample.getSelfBounds().max << std::endl;
    TESTING_ASSERT( curvesSample.getSelfBounds().max == V3d( 1.0, 1.0, 1.0 ) );

    // test other attributes
    TESTING_ASSERT( curvesSample.getPositions() -> size() == 12);

    IFloatGeomParam::Sample widthSample;
    curves.getWidthsParam().getExpanded( widthSample );
    TESTING_ASSERT( widthSample.getVals()->size() == 12);
    TESTING_ASSERT( curves.getWidthsParam().valid() );
    TESTING_ASSERT( widthSample.getScope() == kVertexScope );


}
コード例 #2
0
ファイル: ICurvesDrw.cpp プロジェクト: AWhetter/alembic
//-*****************************************************************************
void ICurvesDrw::setTime( chrono_t iSeconds )
{
    IObjectDrw::setTime( iSeconds );

    // Use nearest for now.
    ISampleSelector ss( iSeconds, ISampleSelector::kNearIndex );
    ICurvesSchema::Sample curvesSample;
    if ( m_curves.getSchema().getNumSamples() > 0 )
    { m_curves.getSchema().get( curvesSample, ss ); }
    else
    { return; }

    m_positions = curvesSample.getPositions();
    m_nCurves = curvesSample.getNumCurves();

    m_nVertices = curvesSample.getCurvesNumVertices();

    m_bounds.makeEmpty();

    m_bounds.extendBy( curvesSample.getSelfBounds() );
}
コード例 #3
0
ファイル: CurvesTest.cpp プロジェクト: AWhetter/alembic
void Example2_CurvesIn()
{
    IArchive archive( Alembic::AbcCoreOgawa::ReadArchive(), "curves2.abc" );

    ICurves myCurves( IObject( archive, kTop) , "nurbsCurve");
    ICurvesSchema &curves = myCurves.getSchema();

    // get the samples from the curves
    ICurvesSchema::Sample curvesSample;
    curves.get( curvesSample );

    // test the bounding box
    TESTING_ASSERT( curvesSample.getSelfBounds().min == V3d( -1.0, -1.0, -1.0 ) );
    TESTING_ASSERT( curvesSample.getSelfBounds().max == V3d( 1.0, 1.0, 1.0 ) );

    // test other attributes
    TESTING_ASSERT( curvesSample.getPositions() -> size() == 12);

    TESTING_ASSERT( curvesSample.getType() == kVariableOrder );
    TESTING_ASSERT( curvesSample.getWrap() == kNonPeriodic );
    TESTING_ASSERT( curvesSample.getBasis() == kBezierBasis );
    TESTING_ASSERT( ( *curvesSample.getOrders() )[0] == 4 );
    TESTING_ASSERT( ( *curvesSample.getOrders() )[1] == 2 );
    TESTING_ASSERT( curvesSample.getPositionWeights()->size() == 12 );
    TESTING_ASSERT( curvesSample.getKnots()->size() == 18 );

    IFloatGeomParam::Sample widthSample;
    curves.getWidthsParam().getExpanded( widthSample );
    TESTING_ASSERT( widthSample.getVals()->size() == 12);
    TESTING_ASSERT( curves.getWidthsParam().valid() );
    TESTING_ASSERT( widthSample.getScope() == kVertexScope );

    IFloatArrayProperty knotsProp = curves.getKnotsProperty();
    TESTING_ASSERT( knotsProp.getNumSamples() == 2 );
    ArraySampleKey keyA, keyB;
    knotsProp.getKey( keyA, 0 );
    knotsProp.getKey( keyB, 1 );
    TESTING_ASSERT( keyA == keyB );
}
コード例 #4
0
ファイル: WriteGeo.cpp プロジェクト: AWhetter/alembic
//-*****************************************************************************
void ProcessCurves( ICurves &curves, ProcArgs &args )
{
    ICurvesSchema &cs = curves.getSchema();
    TimeSamplingPtr ts = cs.getTimeSampling();
    
    SampleTimeSet sampleTimes;
    
    GetRelevantSampleTimes( args, ts, cs.getNumSamples(), sampleTimes );
    
    bool multiSample = sampleTimes.size() > 1;
    
    bool firstSample = true;
    
    for ( SampleTimeSet::iterator iter = sampleTimes.begin();
          iter != sampleTimes.end(); ++iter )
    {
        ISampleSelector sampleSelector( *iter );
        
        ICurvesSchema::Sample sample = cs.getValue( sampleSelector );
        
        //need to set the basis prior to the MotionBegin block
        if ( firstSample )
        {
            firstSample = false;
            
            BasisType basisType = sample.getBasis();
            if ( basisType != kNoBasis )
            {
                RtBasis * basis = NULL;
                RtInt step = 0;
                
                switch ( basisType )
                {
                case kBezierBasis:
                    basis = &RiBezierBasis;
                    step = RI_BEZIERSTEP;
                    break;
                case kBsplineBasis:
                    basis = &RiBSplineBasis;
                    step = RI_BSPLINESTEP;
                    break;
                case kCatmullromBasis:
                    basis = &RiCatmullRomBasis;
                    step = RI_CATMULLROMSTEP;
                    break;
                case kHermiteBasis:
                    basis = &RiHermiteBasis;
                    step = RI_HERMITESTEP;
                    break;
                case kPowerBasis:
                    basis = &RiPowerBasis;
                    step = RI_POWERSTEP;
                    break;
                default:
                    break;
                }
                
                if ( basis != NULL )
                {
                    RiBasis( *basis, step, *basis, step);
                }
            }
            
            
            if ( multiSample ) { WriteMotionBegin( args, sampleTimes ); }
        }
        
        ParamListBuilder paramListBuilder;
        paramListBuilder.add( "P", (RtPointer)sample.getPositions()->get() );
        
        IFloatGeomParam widthParam = cs.getWidthsParam();
        if ( widthParam.valid() )
        {
            ICompoundProperty parent = widthParam.getParent();
            
            //prman requires "width" to be named "constantwidth" when
            //constant instead of declared as "constant float width".
            //It's even got an error message specifically for it.
            std::string widthName;
            if ( widthParam.getScope() == kConstantScope ||
                    widthParam.getScope() == kUnknownScope )
            {
                widthName = "constantwidth";
            }
            else
            {
                widthName = "width";
            }
            
            AddGeomParamToParamListBuilder<IFloatGeomParam>(
                parent,
                widthParam.getHeader(),
                sampleSelector,
                "float",
                paramListBuilder,
                1,
                widthName);
        }
        
        IN3fGeomParam nParam = cs.getNormalsParam();
        if ( nParam.valid() )
        {
            ICompoundProperty parent = nParam.getParent();
            
            AddGeomParamToParamListBuilder<IN3fGeomParam>(
                parent,
                nParam.getHeader(),
                sampleSelector,
                "normal",
                paramListBuilder);
        }
        
        IV2fGeomParam uvParam = cs.getUVsParam();
        if ( uvParam.valid() )
        {
            ICompoundProperty parent = uvParam.getParent();
            
            AddGeomParamToParamListBuilder<IV2fGeomParam>(
                parent,
                uvParam.getHeader(),
                sampleSelector,
                "float",
                paramListBuilder,
                2,
                "st");
        }

        ICompoundProperty arbGeomParams = cs.getArbGeomParams();
        AddArbitraryGeomParams( arbGeomParams,
                    sampleSelector, paramListBuilder );
        
        RtToken curveType;
        switch ( sample.getType() )
        {
        case kCubic:
            curveType = const_cast<RtToken>( "cubic" );
            break;
        default:
            curveType = const_cast<RtToken>( "linear" );
        }
        
        
        RtToken wrap;
        switch ( sample.getWrap() )
        {
        case kPeriodic:
            wrap = const_cast<RtToken>( "periodic" );
            break;
        default:
            wrap = const_cast<RtToken>( "nonperiodic" );
        }

        RiCurvesV(curveType,
                sample.getNumCurves(),
                (RtInt*) sample.getCurvesNumVertices()->get(),
                wrap,
                paramListBuilder.n(),
                paramListBuilder.nms(),
                paramListBuilder.vals() );

    }
    
    if ( multiSample ) { RiMotionEnd(); }
    
}
コード例 #5
0
ファイル: AbcStitcher.cpp プロジェクト: kissinger31/Alembic
//-*****************************************************************************
// a recursive function that reads all inputs and write to the given oObject
// node if there's no gap in the frame range for animated nodes
//
void visitObjects(std::vector< IObject > & iObjects, OObject & oParentObj)
{
    OObject outObj;

    const AbcA::ObjectHeader & header = iObjects[0].getHeader();

    // there are a number of things that needs to be checked for each node
    // to make sure they can be properly stitched together
    //
    // for xform node:
    //      locator or normal xform node
    //      if an xform node, numOps and type of ops match
    //      static or no, and if not, timesampling type matches
    //      if sampled, timesampling type should match
    //      if sampled, no frame gaps
    //
    if (IXform::matches(header))
    {
        OXformSchema oSchema;
        init< IXform,
              IXformSchema,
              OXform,
              OXformSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        ICompoundPropertyVec iCompoundProps;
        iCompoundProps.reserve(iObjects.size());
        ICompoundProperty cp = iObjects[0].getProperties();
        iCompoundProps.push_back(cp);

        bool isLocator = cp.getPropertyHeader("locator")?true:false;

        for (size_t i = 1; i < iObjects.size(); i++)
        {
            ICompoundProperty cp = iObjects[i].getProperties();
            iCompoundProps.push_back(cp);
        }

        // stitch the operations if this is an xform node

        for (size_t i = 0; i < iObjects.size(); i++)
        {
            IXformSchema iSchema =
                IXform(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            index_t numSamples = iSchema.getNumSamples();
            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                XformSample samp = iSchema.getValue(reqIdx);
                oSchema.set(samp);
            }
        }

        // stitch "locator" if it's a locator
        OCompoundProperty oCompoundProp = outObj.getProperties();
        if (isLocator)
        {
            const PropertyHeader * propHeaderPtr =
                iCompoundProps[0].getPropertyHeader("locator");
            stitchScalarProp(*propHeaderPtr,
                             iCompoundProps,
                             oCompoundProp);
        }
    }
    else if (ISubD::matches(header))
    {
        OSubDSchema oSchema;
        init< ISubD,
              ISubDSchema,
              OSubD,
              OSubDSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the SubDSchema
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            ISubDSchema iSchema =
                ISubD(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            index_t numSamples = iSchema.getNumSamples();
            IV2fGeomParam uvs = iSchema.getUVsParam();
            if (i == 0 && uvs)
            {
                oSchema.setUVSourceName(GetSourceName(uvs.getMetaData()));
            }
            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                ISubDSchema::Sample iSamp = iSchema.getValue(reqIdx);
                OSubDSchema::Sample oSamp;

                Abc::P3fArraySamplePtr posPtr = iSamp.getPositions();
                if (posPtr)
                    oSamp.setPositions(*posPtr);

                Abc::V3fArraySamplePtr velocPtr = iSamp.getVelocities();
                if (velocPtr)
                    oSamp.setVelocities(*velocPtr);

                Abc::Int32ArraySamplePtr faceIndicesPtr = iSamp.getFaceIndices();
                if (faceIndicesPtr)
                    oSamp.setFaceIndices(*faceIndicesPtr);

                Abc::Int32ArraySamplePtr faceCntPtr = iSamp.getFaceCounts();
                if (faceCntPtr)
                    oSamp.setFaceCounts(*faceCntPtr);

                oSamp.setFaceVaryingInterpolateBoundary(iSamp.getFaceVaryingInterpolateBoundary());
                oSamp.setFaceVaryingPropagateCorners(iSamp.getFaceVaryingPropagateCorners());
                oSamp.setInterpolateBoundary(iSamp.getInterpolateBoundary());

                Abc::Int32ArraySamplePtr creaseIndicesPtr = iSamp.getCreaseIndices();
                if (creaseIndicesPtr)
                    oSamp.setCreaseIndices(*creaseIndicesPtr);

                Abc::Int32ArraySamplePtr creaseLenPtr = iSamp.getCreaseLengths();
                if (creaseLenPtr)
                    oSamp.setCreaseLengths(*creaseLenPtr);

                Abc::FloatArraySamplePtr creaseSpPtr = iSamp.getCreaseSharpnesses();
                if (creaseSpPtr)
                    oSamp.setCreaseSharpnesses(*creaseSpPtr);

                Abc::Int32ArraySamplePtr cornerIndicesPtr = iSamp.getCornerIndices();
                if (cornerIndicesPtr)
                    oSamp.setCornerIndices(*cornerIndicesPtr);

                Abc::FloatArraySamplePtr cornerSpPtr = iSamp.getCornerSharpnesses();
                if (cornerSpPtr)
                    oSamp.setCreaseSharpnesses(*cornerSpPtr);

                Abc::Int32ArraySamplePtr holePtr = iSamp.getHoles();
                if (holePtr)
                    oSamp.setHoles(*holePtr);

                oSamp.setSubdivisionScheme(iSamp.getSubdivisionScheme());

                // set uvs
                IV2fGeomParam::Sample iUVSample;
                OV2fGeomParam::Sample oUVSample;
                if (uvs)
                {
                    getOGeomParamSamp <IV2fGeomParam, IV2fGeomParam::Sample,
                        OV2fGeomParam::Sample>(uvs, iUVSample,
                                               oUVSample, reqIdx);
                    oSamp.setUVs(oUVSample);
                }

                oSchema.set(oSamp);
            }
        }
    }
    else if (IPolyMesh::matches(header))
    {
        OPolyMeshSchema oSchema;
        init< IPolyMesh,
              IPolyMeshSchema,
              OPolyMesh,
              OPolyMeshSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the PolySchema
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            IPolyMeshSchema iSchema =
                IPolyMesh(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            index_t numSamples = iSchema.getNumSamples();

            IN3fGeomParam normals = iSchema.getNormalsParam();
            IV2fGeomParam uvs = iSchema.getUVsParam();
            if (i == 0 && uvs)
            {
                oSchema.setUVSourceName(GetSourceName(uvs.getMetaData()));
            }
            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                IPolyMeshSchema::Sample iSamp = iSchema.getValue(reqIdx);
                OPolyMeshSchema::Sample oSamp;

                Abc::P3fArraySamplePtr posPtr = iSamp.getPositions();
                if (posPtr)
                    oSamp.setPositions(*posPtr);

                Abc::V3fArraySamplePtr velocPtr = iSamp.getVelocities();
                if (velocPtr)
                    oSamp.setVelocities(*velocPtr);

                Abc::Int32ArraySamplePtr faceIndicesPtr = iSamp.getFaceIndices();
                if (faceIndicesPtr)
                    oSamp.setFaceIndices(*faceIndicesPtr);

                Abc::Int32ArraySamplePtr faceCntPtr = iSamp.getFaceCounts();
                if (faceCntPtr)
                    oSamp.setFaceCounts(*faceCntPtr);

                // set uvs
                IV2fGeomParam::Sample iUVSample;
                OV2fGeomParam::Sample oUVSample;
                if (uvs)
                {
                    getOGeomParamSamp <IV2fGeomParam, IV2fGeomParam::Sample,
                        OV2fGeomParam::Sample>(uvs, iUVSample,
                                               oUVSample, reqIdx);
                    oSamp.setUVs(oUVSample);
                }

                // set normals
                IN3fGeomParam::Sample iNormalsSample;
                ON3fGeomParam::Sample oNormalsSample;
                if (normals)
                {
                    getOGeomParamSamp <IN3fGeomParam, IN3fGeomParam::Sample,
                        ON3fGeomParam::Sample>(normals, iNormalsSample,
                                               oNormalsSample, reqIdx);
                    oSamp.setNormals(oNormalsSample);
                }

                oSchema.set(oSamp);
            }
        }
    }
    else if (ICamera::matches(header))
    {
        OCameraSchema oSchema;
        init< ICamera,
              ICameraSchema,
              OCamera,
              OCameraSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the CameraSchemas
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            ICameraSchema iSchema =
                ICamera(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            index_t numSamples = iSchema.getNumSamples();
            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                oSchema.set(iSchema.getValue(reqIdx));
            }
        }
    }
    else if (ICurves::matches(header))
    {
        OCurvesSchema oSchema;
        init< ICurves,
              ICurvesSchema,
              OCurves,
              OCurvesSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the CurvesSchemas
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            ICurvesSchema iSchema =
                ICurves(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            IV2fGeomParam iUVs = iSchema.getUVsParam();
            IN3fGeomParam iNormals = iSchema.getNormalsParam();
            IFloatGeomParam iWidths = iSchema.getWidthsParam();
            IFloatArrayProperty iKnots = iSchema.getKnotsProperty();
            IUcharArrayProperty iOrders = iSchema.getOrdersProperty();

            index_t numSamples = iSchema.getNumSamples();

            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                ICurvesSchema::Sample iSamp = iSchema.getValue(reqIdx);

                OCurvesSchema::Sample oSamp;
                Abc::P3fArraySamplePtr posPtr = iSamp.getPositions();
                if (posPtr)
                    oSamp.setPositions(*posPtr);

                Abc::V3fArraySamplePtr velocPtr = iSamp.getVelocities();
                if (velocPtr)
                    oSamp.setVelocities(*velocPtr);

                oSamp.setType(iSamp.getType());
                Abc::Int32ArraySamplePtr curvsNumPtr = iSamp.getCurvesNumVertices();
                if (curvsNumPtr)
                    oSamp.setCurvesNumVertices(*curvsNumPtr);
                oSamp.setWrap(iSamp.getWrap());
                oSamp.setBasis(iSamp.getBasis());

                Abc::FloatArraySamplePtr knotsPtr = iSamp.getKnots();
                if (knotsPtr)
                {
                    oSamp.setKnots(*knotsPtr);
                }

                Abc::UcharArraySamplePtr ordersPtr = iSamp.getOrders();
                if (ordersPtr)
                {
                    oSamp.setOrders(*ordersPtr);
                }

                IFloatGeomParam::Sample iWidthSample;
                OFloatGeomParam::Sample oWidthSample;
                if (iWidths)
                {
                    getOGeomParamSamp <IFloatGeomParam, IFloatGeomParam::Sample,
                        OFloatGeomParam::Sample>(iWidths, iWidthSample,
                                                 oWidthSample, reqIdx);
                    oSamp.setWidths(oWidthSample);
                }

                IV2fGeomParam::Sample iUVSample;
                OV2fGeomParam::Sample oUVSample;
                if (iUVs)
                {
                    getOGeomParamSamp <IV2fGeomParam, IV2fGeomParam::Sample,
                        OV2fGeomParam::Sample>(iUVs, iUVSample,
                                               oUVSample, reqIdx);
                    oSamp.setUVs(oUVSample);
                }

                IN3fGeomParam::Sample iNormalsSample;
                ON3fGeomParam::Sample oNormalsSample;
                if (iNormals)
                {
                    getOGeomParamSamp <IN3fGeomParam, IN3fGeomParam::Sample,
                        ON3fGeomParam::Sample>(iNormals, iNormalsSample,
                                               oNormalsSample, reqIdx);
                    oSamp.setNormals(oNormalsSample);
                }

                oSchema.set(oSamp);
            }
        }
    }
    else if (IPoints::matches(header))
    {
        OPointsSchema oSchema;
        init< IPoints,
              IPointsSchema,
              OPoints,
              OPointsSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the PointsSchemas
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            IPointsSchema iSchema =
                IPoints(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            IFloatGeomParam iWidths = iSchema.getWidthsParam();
            index_t numSamples = iSchema.getNumSamples();
            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                IPointsSchema::Sample iSamp = iSchema.getValue(reqIdx);
                OPointsSchema::Sample oSamp;
                Abc::P3fArraySamplePtr posPtr = iSamp.getPositions();
                if (posPtr)
                    oSamp.setPositions(*posPtr);
                Abc::UInt64ArraySamplePtr idPtr = iSamp.getIds();
                if (idPtr)
                    oSamp.setIds(*idPtr);
                Abc::V3fArraySamplePtr velocPtr = iSamp.getVelocities();
                if (velocPtr)
                    oSamp.setVelocities(*velocPtr);

                IFloatGeomParam::Sample iWidthSample;
                OFloatGeomParam::Sample oWidthSample;
                if (iWidths)
                {
                    getOGeomParamSamp <IFloatGeomParam, IFloatGeomParam::Sample,
                        OFloatGeomParam::Sample>(iWidths, iWidthSample,
                                                 oWidthSample, reqIdx);
                    oSamp.setWidths(oWidthSample);
                }

                oSchema.set(oSamp);
            }
        }
    }
    else if (INuPatch::matches(header))
    {
        ONuPatchSchema oSchema;
        init< INuPatch,
              INuPatchSchema,
              ONuPatch,
              ONuPatchSchema >(iObjects, oParentObj, oSchema);
        outObj = oSchema.getObject();

        // stitch the NuPatchSchemas
        //
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            INuPatchSchema iSchema =
                INuPatch(iObjects[i], Alembic::Abc::kWrapExisting).getSchema();
            index_t numSamples = iSchema.getNumSamples();

            IN3fGeomParam normals = iSchema.getNormalsParam();
            IV2fGeomParam uvs = iSchema.getUVsParam();

            index_t reqIdx = getIndexSample(oSchema.getNumSamples(),
                oSchema.getTimeSampling(), numSamples,
                iSchema.getTimeSampling());
            for (; reqIdx < numSamples; reqIdx++)
            {
                INuPatchSchema::Sample iSamp = iSchema.getValue(reqIdx);
                ONuPatchSchema::Sample oSamp;

                Abc::P3fArraySamplePtr posPtr = iSamp.getPositions();
                if (posPtr)
                    oSamp.setPositions(*posPtr);

                Abc::V3fArraySamplePtr velocPtr = iSamp.getVelocities();
                if (velocPtr)
                    oSamp.setVelocities(*velocPtr);

                oSamp.setNu(iSamp.getNumU());
                oSamp.setNv(iSamp.getNumV());
                oSamp.setUOrder(iSamp.getUOrder());
                oSamp.setVOrder(iSamp.getVOrder());

                Abc::FloatArraySamplePtr uKnotsPtr = iSamp.getUKnot();
                if (uKnotsPtr)
                    oSamp.setUKnot(*uKnotsPtr);

                Abc::FloatArraySamplePtr vKnotsPtr = iSamp.getVKnot();
                if (vKnotsPtr)
                    oSamp.setVKnot(*vKnotsPtr);

                IV2fGeomParam::Sample iUVSample;
                OV2fGeomParam::Sample oUVSample;
                if (uvs)
                {
                    getOGeomParamSamp <IV2fGeomParam, IV2fGeomParam::Sample,
                        OV2fGeomParam::Sample>(uvs, iUVSample,
                                               oUVSample, reqIdx);
                    oSamp.setUVs(oUVSample);
                }

                IN3fGeomParam::Sample iNormalsSample;
                ON3fGeomParam::Sample oNormalsSample;
                if (normals)
                {
                    getOGeomParamSamp <IN3fGeomParam, IN3fGeomParam::Sample,
                        ON3fGeomParam::Sample>(normals, iNormalsSample,
                                               oNormalsSample, reqIdx);
                    oSamp.setNormals(oNormalsSample);
                }


                if (iSchema.hasTrimCurve())
                {
                    oSamp.setTrimCurve(iSamp.getTrimNumLoops(),
                                       *(iSamp.getTrimNumCurves()),
                                       *(iSamp.getTrimNumVertices()),
                                       *(iSamp.getTrimOrders()),
                                       *(iSamp.getTrimKnots()),
                                       *(iSamp.getTrimMins()),
                                       *(iSamp.getTrimMaxes()),
                                       *(iSamp.getTrimU()),
                                       *(iSamp.getTrimV()),
                                       *(iSamp.getTrimW()));
                }
                oSchema.set(oSamp);
            }
        }
    }
    else
    {
        outObj = OObject(oParentObj, header.getName(), header.getMetaData());

        // collect the top level compound property
        ICompoundPropertyVec iCompoundProps(iObjects.size());
        for (size_t i = 0; i < iObjects.size(); i++)
        {
            iCompoundProps[i] = iObjects[i].getProperties();
        }

        OCompoundProperty oCompoundProperty = outObj.getProperties();
        stitchCompoundProp(iCompoundProps, oCompoundProperty);
    }

    // After done writing THIS OObject node, if input nodes have children,
    // go deeper.
    // Otherwise we are done here
    size_t numChildren =  iObjects[0].getNumChildren();

    // check to make sure all of our iObjects have the same number of children
    for (size_t j = 1; j < iObjects.size(); j++)
    {
        if (numChildren != iObjects[j].getNumChildren())
        {
            std::cerr << "ERROR: " << iObjects[j].getFullName() << " in " <<
                iObjects[j].getArchive().getName() <<
                " has a different number of children than " <<
                iObjects[0].getFullName() << " in " <<
                iObjects[0].getArchive().getName() << std::endl;

            exit(1);
        }
    }

    for (size_t i = 0 ; i < numChildren; i++ )
    {
        std::vector< IObject > iChildObjects;
        for (size_t f = 0; f < iObjects.size(); f++)
        {
            iChildObjects.push_back(iObjects[f].getChild(i));
        }
        visitObjects(iChildObjects, outObj);
    }

}