readerwriterobj.cpp

最新osg包

    
    if (vertices) vertices->reserve(numVertexIndices);
    if (normals) normals->reserve(numNormalIndices);
    if (texcoords) texcoords->reserve(numTexCoordIndices);
    
    osg::Geometry* geometry = new osg::Geometry;
    if (vertices) geometry->setVertexArray(vertices);
    if (normals)
    {
        geometry->setNormalArray(normals);
        geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
    }
    if (texcoords)
    {
        geometry->setTexCoordArray(0,texcoords);
    }
    

    if (numPointElements>0)
    {
        unsigned int startPos = vertices->size();
        unsigned int numPoints = 0;
        for(itr=elementList.begin();
            itr!=elementList.end();
            ++itr)
        {
            obj::Element& element = *(*itr);
            if (element.dataType==obj::Element::POINTS)
            {
                for(obj::Element::IndexList::iterator index_itr = element.vertexIndices.begin();
                    index_itr != element.vertexIndices.end();
                    ++index_itr)
                {
                    vertices->push_back(transformVertex(model.vertices[*index_itr],rotate));
                    ++numPoints;
                }
                if (numNormalIndices)
                {
                    for(obj::Element::IndexList::iterator index_itr = element.normalIndices.begin();
                        index_itr != element.normalIndices.end();
                        ++index_itr)
                    {
                        normals->push_back(transformNormal(model.normals[*index_itr],rotate));
                    }
                }
                if (numTexCoordIndices)
                {
                    for(obj::Element::IndexList::iterator index_itr = element.texCoordIndices.begin();
                        index_itr != element.texCoordIndices.end();
                        ++index_itr)
                    {
                        texcoords->push_back(model.texcoords[*index_itr]);
                    }
                }
            }
        }

        osg::DrawArrays* drawArrays = new osg::DrawArrays(GL_POINTS,startPos,numPoints);
        geometry->addPrimitiveSet(drawArrays);
    }
    
    if (numPolylineElements>0)
    {
        unsigned int startPos = vertices->size();
        osg::DrawArrayLengths* drawArrayLengths = new osg::DrawArrayLengths(GL_LINES,startPos);

        for(itr=elementList.begin();
            itr!=elementList.end();
            ++itr)
        {
            obj::Element& element = *(*itr);
            if (element.dataType==obj::Element::POLYLINE)
            {
                drawArrayLengths->push_back(element.vertexIndices.size());

                for(obj::Element::IndexList::iterator index_itr = element.vertexIndices.begin();
                    index_itr != element.vertexIndices.end();
                    ++index_itr)
                {
                    vertices->push_back(transformVertex(model.vertices[*index_itr],rotate));
                }
                if (numNormalIndices)
                {
                    for(obj::Element::IndexList::iterator index_itr = element.normalIndices.begin();
                        index_itr != element.normalIndices.end();
                        ++index_itr)
                    {
                        normals->push_back(transformNormal(model.normals[*index_itr],rotate));
                    }
                }
                if (numTexCoordIndices)
                {
                    for(obj::Element::IndexList::iterator index_itr = element.texCoordIndices.begin();
                        index_itr != element.texCoordIndices.end();
                        ++index_itr)
                    {
                        texcoords->push_back(model.texcoords[*index_itr]);
                    }
                }
            }
        }

        geometry->addPrimitiveSet(drawArrayLengths);

    }

    // #define USE_DRAWARRAYLENGTHS

    if (numPolygonElements>0)
    {
        unsigned int startPos = vertices->size();
        
        #ifdef USE_DRAWARRAYLENGTHS
            osg::DrawArrayLengths* drawArrayLengths = new osg::DrawArrayLengths(GL_POLYGON,startPos);
            geometry->addPrimitiveSet(drawArrayLengths);
        #endif

        for(itr=elementList.begin();
            itr!=elementList.end();
            ++itr)
        {
            obj::Element& element = *(*itr);
            if (element.dataType==obj::Element::POLYGON)
            {

                #ifdef USE_DRAWARRAYLENGTHS
                    drawArrayLengths->push_back(element.vertexIndices.size());
                #else
                    if (element.vertexIndices.size()>4)
                    {
                        osg::DrawArrays* drawArrays = new osg::DrawArrays(GL_POLYGON,startPos,element.vertexIndices.size());
                        startPos += element.vertexIndices.size();
                        geometry->addPrimitiveSet(drawArrays);
                    }
                    else
                    {
                        osg::DrawArrays* drawArrays = new osg::DrawArrays(GL_TRIANGLE_FAN,startPos,element.vertexIndices.size());
                        startPos += element.vertexIndices.size();
                        geometry->addPrimitiveSet(drawArrays);
                    }
                #endif

            
                if (model.needReverse(element))
                {
                    // need to reverse so add to OSG arrays in same order as in OBJ, as OSG assume anticlockwise ordering.
                    for(obj::Element::IndexList::reverse_iterator index_itr = element.vertexIndices.rbegin();
                        index_itr != element.vertexIndices.rend();
                        ++index_itr)
                    {
                        vertices->push_back(transformVertex(model.vertices[*index_itr],rotate));
                    }
                    if (numNormalIndices)
                    {
                        for(obj::Element::IndexList::reverse_iterator index_itr = element.normalIndices.rbegin();
                            index_itr != element.normalIndices.rend();
                            ++index_itr)
                        {
                            normals->push_back(transformNormal(model.normals[*index_itr],rotate));
                        }
                    }
                    if (numTexCoordIndices)
                    {
                        for(obj::Element::IndexList::reverse_iterator index_itr = element.texCoordIndices.rbegin();
                            index_itr != element.texCoordIndices.rend();
                            ++index_itr)
                        {
                            texcoords->push_back(model.texcoords[*index_itr]);
                        }
                    }
                }
                else
                {
                    // no need to reverse so add to OSG arrays in same order as in OBJ.
                    for(obj::Element::IndexList::iterator index_itr = element.vertexIndices.begin();
                        index_itr != element.vertexIndices.end();
                        ++index_itr)
                    {
                        vertices->push_back(transformVertex(model.vertices[*index_itr],rotate));
                    }
                    if (numNormalIndices)
                    {
                        for(obj::Element::IndexList::iterator index_itr = element.normalIndices.begin();
                            index_itr != element.normalIndices.end();
                            ++index_itr)
                        {
                            normals->push_back(transformNormal(model.normals[*index_itr],rotate));
                        }
                    }
                    if (numTexCoordIndices)
                    {
                        for(obj::Element::IndexList::iterator index_itr = element.texCoordIndices.begin();
                            index_itr != element.texCoordIndices.end();
                            ++index_itr)
                        {
                            texcoords->push_back(model.texcoords[*index_itr]);
                        }
                    }
                }
            }
        }


    }
    
    return geometry;
}

osg::Node* ReaderWriterOBJ::convertModelToSceneGraph(obj::Model& model,
    bool& rotate, bool& noTesselateLargePolygons, bool& noTriStripPolygons) const
{

    if (model.elementStateMap.empty()) return 0;

    osg::Group* group = new osg::Group;

    // set up the materials
    MaterialToStateSetMap materialToSetSetMap;
    buildMaterialToStateSetMap(model, materialToSetSetMap);

    // go through the groups of related elements and build geometry from them.
    for(obj::Model::ElementStateMap::iterator itr=model.elementStateMap.begin();
        itr!=model.elementStateMap.end();
        ++itr)
    {
    
        const obj::ElementState& es = itr->first;
        obj::Model::ElementList& el = itr->second;

        osg::Geometry* geometry = convertElementListToGeometry(model,el,rotate);

        if (geometry)
        {

            osg::StateSet* stateset = materialToSetSetMap[es.materialName].get();
            geometry->setStateSet(stateset);
        
            // tesseleate any large polygons
            if (!noTesselateLargePolygons)
            {
                osgUtil::Tessellator tessellator;
                tessellator.retessellatePolygons(*geometry);
            }
            
            // tri strip polygons to improve graphics peformance
            if (!noTriStripPolygons)
            {
                osgUtil::TriStripVisitor tsv;
                tsv.stripify(*geometry);
            }
            
            // if no normals present add them.
            if (!geometry->getNormalArray() || geometry->getNormalArray()->getNumElements()==0)
            {
                osgUtil::SmoothingVisitor sv;
                sv.smooth(*geometry);
            }


            osg::Geode* geode = new osg::Geode;
            geode->addDrawable(geometry);
            
            if (es.objectName.empty())
            {
                geode->setName(es.groupName);
            }
            else if (es.groupName.empty())
            {
                geode->setName(es.objectName);
            }
            else
            {
                geode->setName(es.groupName + std::string(":") + es.objectName);
            }

            group->addChild(geode);

        }
    }

    return group;
}


// read file and convert to OSG.
osgDB::ReaderWriter::ReadResult ReaderWriterOBJ::readNode(const std::string& file, const osgDB::ReaderWriter::Options* options) const
{
    std::string ext = osgDB::getLowerCaseFileExtension(file);
    if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;

    std::string fileName = osgDB::findDataFile( file, options );
    if (fileName.empty()) return ReadResult::FILE_NOT_FOUND;
    
    
    osgDB::ifstream fin(fileName.c_str());
    if (fin)
    {
    
        // code for setting up the database path so that internally referenced file are searched for on relative paths. 
        osg::ref_ptr<Options> local_opt = options ? static_cast<Options*>(options->clone(osg::CopyOp::SHALLOW_COPY)) : new Options;
        local_opt->setDatabasePath(osgDB::getFilePath(fileName));

        obj::Model model;
        model.setDatabasePath(osgDB::getFilePath(fileName.c_str()));
        model.readOBJ(fin, local_opt.get());
        
        // code for checking the nonRotation, noTesselateLargePolygons,
        // and noTriStripPolygons
        bool rotate = true;
        bool noTesselateLargePolygons = false;
        bool noTriStripPolygons = false;
        
        if (options!=NULL)
        {
            if (options->getOptionString() == "noRotation")
            {
                rotate = false;
            }
            
            if (options->getOptionString() == "noTesselateLargePolygons")
            {
                noTesselateLargePolygons = true;
            }
            
            if (options->getOptionString() == "noTriStripPolygons")
            {
                noTriStripPolygons = true;
            }
        }
        
        osg::Node* node = convertModelToSceneGraph(model,rotate,
            noTesselateLargePolygons,noTriStripPolygons);
        return node;
    }
    
    return ReadResult::FILE_NOT_HANDLED;
}

osgDB::ReaderWriter::ReadResult ReaderWriterOBJ::readNode(std::istream& fin, const Options* options) const
{
    if (fin)
    {
        obj::Model model;
        model.readOBJ(fin, options);
        
        // code for checking the nonRotation, noTesselateLargePolygons,
        // and noTriStripPolygons
        bool rotate = true;
        bool noTesselateLargePolygons = false;
        bool noTriStripPolygons = false;
        
        if (options!=NULL)
        {
            if (options->getOptionString() == "noRotation")
            {
                rotate = false;
            }
            
            if (options->getOptionString() == "noTesselateLargePolygons")
            {
                noTesselateLargePolygons = true;
            }
            
            if (options->getOptionString() == "noTriStripPolygons")
            {
                noTriStripPolygons = true;
            }
        }
        
        osg::Node* node = convertModelToSceneGraph(model,rotate,
            noTesselateLargePolygons,noTriStripPolygons);
        return node;
    }
    
    return ReadResult::FILE_NOT_HANDLED;
}