//-*****************************************************************************
void ISubDDrw::setTime( chrono_t iSeconds )
{
    IObjectDrw::setTime( iSeconds );
    if ( !valid() )
    {
        m_drwHelper.makeInvalid();
        return;
    }

    // Use nearest for now.
    ISampleSelector ss( iSeconds, ISampleSelector::kNearIndex );
    ISubDSchema::Sample psamp;

    if ( m_subD.getSchema().isConstant() )
    {
        psamp = m_samp;
    }
    else if ( m_subD.getSchema().getNumSamples() > 0 )
    {
        m_subD.getSchema().get( psamp, ss );
    }

    // Get the stuff.
    P3fArraySamplePtr P = psamp.getPositions();
    Int32ArraySamplePtr indices = psamp.getFaceIndices();
    Int32ArraySamplePtr counts = psamp.getFaceCounts();

    Box3d bounds;
    bounds.makeEmpty();

    if ( m_boundsProp && m_boundsProp.getNumSamples() > 0 )
    { bounds = m_boundsProp.getValue( ss ); }

    // Update the mesh hoo-ha.
    m_drwHelper.update( P, V3fArraySamplePtr(),
                        indices, counts, bounds );

    if ( !m_drwHelper.valid() )
    {
        m_subD.reset();
        return;
    }

    // The Object update computed child bounds.
    // Extend them by this.
    if ( !m_drwHelper.getBounds().isEmpty() )
    {
        m_bounds.extendBy( m_drwHelper.getBounds() );
    }
}
Example #2
0
//-*****************************************************************************
void ProcessSubD( ISubD &subd, ProcArgs &args, const std::string & facesetName )
{
    ISubDSchema &ss = subd.getSchema();

    TimeSamplingPtr ts = ss.getTimeSampling();

    SampleTimeSet sampleTimes;
    GetRelevantSampleTimes( args, ts, ss.getNumSamples(), sampleTimes );

    bool multiSample = sampleTimes.size() > 1;

    //include this code path for future expansion
    bool isHierarchicalSubD = false;
    bool hasLocalResources = false;
    
    
    
    std::vector<IFaceSet> faceSets;
    std::vector<std::string> faceSetResourceNames;
    if ( facesetName.empty() )
    {
        std::vector <std::string> childFaceSetNames;
        ss.getFaceSetNames(childFaceSetNames);
        
        faceSets.reserve(childFaceSetNames.size());
        faceSetResourceNames.reserve(childFaceSetNames.size());
        
        for (size_t i = 0; i < childFaceSetNames.size(); ++i)
        {
            faceSets.push_back(ss.getFaceSet(childFaceSetNames[i]));
            
            IFaceSet & faceSet = faceSets.back();
            
            std::string resourceName = args.getResource(
                    faceSet.getFullName() );
            
            if ( resourceName.empty() )
            {
                resourceName = args.getResource( faceSet.getName() );
            }
            
#ifdef PRMAN_USE_ABCMATERIAL
                
                Mat::MaterialFlatten mafla(faceSet);
                
                if (!mafla.empty())
                {
                    if (!hasLocalResources)
                    {
                        RiResourceBegin();
                        hasLocalResources = true;
                    }
                    
                    RiAttributeBegin();
                    
                    if ( !resourceName.empty() )
                    {
                        //restore existing resource state here
                        RestoreResource( resourceName );
                    }
                    
                    
                    WriteMaterial( mafla, args );
                    
                    resourceName = faceSet.getFullName();
                    SaveResource( resourceName );
                    
                    RiAttributeEnd();
                }
#endif
            faceSetResourceNames.push_back(resourceName);
            
        }
    }
#ifdef PRMAN_USE_ABCMATERIAL    
    else
    {
        //handle single faceset material directly
        if ( ss.hasFaceSet( facesetName ) )
        {
            IFaceSet faceSet = ss.getFaceSet( facesetName );
            ApplyObjectMaterial(faceSet, args);
            
        }
    }
#endif
    
    
    
    
    

    if ( multiSample ) { WriteMotionBegin( args, sampleTimes ); }

    for ( SampleTimeSet::iterator iter = sampleTimes.begin();
          iter != sampleTimes.end(); ++iter )
    {
        
        ISampleSelector sampleSelector( *iter );

        ISubDSchema::Sample sample = ss.getValue( sampleSelector );

        RtInt npolys = (RtInt) sample.getFaceCounts()->size();

        ParamListBuilder paramListBuilder;

        paramListBuilder.add( "P", (RtPointer)sample.getPositions()->get() );

        IV2fGeomParam uvParam = ss.getUVsParam();
        if ( uvParam.valid() )
        {
            ICompoundProperty parent = uvParam.getParent();
            
            if ( !args.flipv )
            {
                AddGeomParamToParamListBuilder<IV2fGeomParam>(
                    parent,
                    uvParam.getHeader(),
                    sampleSelector,
                    "float",
                    paramListBuilder,
                    2,
                    "st");
            }
            else if ( std::vector<float> * values =
                    AddGeomParamToParamListBuilderAsFloat<IV2fGeomParam, float>(
                        parent,
                        uvParam.getHeader(),
                        sampleSelector,
                        "float",
                        paramListBuilder,
                        "st") )
            {
                for ( size_t i = 1, e = values->size(); i < e; i += 2 )
                {
                    (*values)[i] = 1.0 - (*values)[i];
                }
            }
            
        }

        ICompoundProperty arbGeomParams = ss.getArbGeomParams();
        AddArbitraryGeomParams( arbGeomParams,
                    sampleSelector, paramListBuilder );

        std::string subdScheme = sample.getSubdivisionScheme();

        SubDTagBuilder tags;

        ProcessFacevaryingInterpolateBoundry( tags, sample );
        ProcessInterpolateBoundry( tags, sample );
        ProcessFacevaryingPropagateCorners( tags, sample );
        ProcessHoles( tags, sample );
        ProcessCreases( tags, sample );
        ProcessCorners( tags, sample );
        
        if ( !facesetName.empty() )
        {
            if ( ss.hasFaceSet( facesetName ) )
            {
                IFaceSet faceSet = ss.getFaceSet( facesetName );
                
                ApplyResources( faceSet, args );
                
                // TODO, move the hold test outside of MotionBegin
                // as it's not meaningful to change per sample
                
                IFaceSetSchema::Sample faceSetSample = 
                        faceSet.getSchema().getValue( sampleSelector );
                
                std::set<int> facesToKeep;
                
                facesToKeep.insert( faceSetSample.getFaces()->get(),
                        faceSetSample.getFaces()->get() +
                                faceSetSample.getFaces()->size() );
                
                for ( int i = 0; i < npolys; ++i )
                {
                    if ( facesToKeep.find( i ) == facesToKeep.end() )
                    {
                        tags.add( "hole" );
                        tags.addIntArg( i );
                    }
                }
            }
        }
        else
        {
            //loop through the facesets and determine whether there are any
            //resources assigned to each
            
            for (size_t i = 0; i < faceSetResourceNames.size(); ++i)
            {
                const std::string & resourceName = faceSetResourceNames[i];
                
                //TODO, visibility?
                
                if ( !resourceName.empty() )
                {
                    IFaceSet & faceSet = faceSets[i];
                    
                    isHierarchicalSubD = true;
                    
                    tags.add("faceedit");
                    
                    Int32ArraySamplePtr faces = faceSet.getSchema().getValue(
                            sampleSelector ).getFaces();
                    
                    for (size_t j = 0, e = faces->size(); j < e; ++j)
                    {
                        tags.addIntArg(1); //yep, every face gets a 1 in front of it too
                        tags.addIntArg( (int) faces->get()[j]);
                    }
                    
                    tags.addStringArg( "attributes" );
                    tags.addStringArg( resourceName );
                    tags.addStringArg( "shading" );
                }
            }
        }


        if ( isHierarchicalSubD )
        {
            RiHierarchicalSubdivisionMeshV(
                const_cast<RtToken>( subdScheme.c_str() ),
                npolys,
                (RtInt*) sample.getFaceCounts()->get(),
                (RtInt*) sample.getFaceIndices()->get(),
                tags.nt(),
                tags.tags(),
                tags.nargs( true ),
                tags.intargs(),
                tags.floatargs(),
                tags.stringargs(),
                paramListBuilder.n(),
                paramListBuilder.nms(),
                paramListBuilder.vals()
                                          );
        }
        else
        {
            RiSubdivisionMeshV(
                const_cast<RtToken>(subdScheme.c_str() ),
                npolys,
                (RtInt*) sample.getFaceCounts()->get(),
                (RtInt*) sample.getFaceIndices()->get(),
                tags.nt(),
                tags.tags(),
                tags.nargs( false ),
                tags.intargs(),
                tags.floatargs(),
                paramListBuilder.n(),
                paramListBuilder.nms(),
                paramListBuilder.vals()
                              );
        }
    }

    if ( multiSample ) { RiMotionEnd(); }
    
    if ( hasLocalResources ) { RiResourceEnd(); }
}
Example #3
0
//-*****************************************************************************
// 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);
    }

}