diff --git a/Make/makedirdefs b/Make/makedirdefs index 0517a13f0..54f57fa23 100644 --- a/Make/makedirdefs +++ b/Make/makedirdefs @@ -219,6 +219,7 @@ EXAMPLE_DIRS = \ osgscribe\ osgsequence\ osgshaders\ + osgshaderterrain\ osgshadowtexture\ osgshape\ osgsimple\ diff --git a/examples/osgforest/osgforest.cpp b/examples/osgforest/osgforest.cpp index ffeb40418..46f9fd13c 100644 --- a/examples/osgforest/osgforest.cpp +++ b/examples/osgforest/osgforest.cpp @@ -1000,7 +1000,7 @@ osg::Node* ForestTechniqueManager::createScene(unsigned int numTreesToCreates) osg::Program* program = new osg::Program; stateset->setAttribute(program); -#if 1 +#if 0 // use inline shaders /////////////////////////////////////////////////////////////////// diff --git a/examples/osgshaderterrain/GNUmakefile b/examples/osgshaderterrain/GNUmakefile new file mode 100644 index 000000000..a58445cdd --- /dev/null +++ b/examples/osgshaderterrain/GNUmakefile @@ -0,0 +1,17 @@ +TOPDIR = ../.. +include $(TOPDIR)/Make/makedefs + +CXXFILES =\ + osgshaderterrain.cpp\ + +LIBS += -losgProducer -lProducer -losgText -losgGA -losgDB -losgUtil -losg $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS) + +INSTFILES = \ + $(CXXFILES)\ + GNUmakefile.inst=GNUmakefile + +EXEC = osgshaderterrain + +INC += $(X_INC) + +include $(TOPDIR)/Make/makerules diff --git a/examples/osgshaderterrain/GNUmakefile.inst b/examples/osgshaderterrain/GNUmakefile.inst new file mode 100644 index 000000000..035a78152 --- /dev/null +++ b/examples/osgshaderterrain/GNUmakefile.inst @@ -0,0 +1,14 @@ +TOPDIR = ../.. +include $(TOPDIR)/Make/makedefs + +CXXFILES =\ + osgforest.cpp\ + +LIBS += -losgProducer -lProducer -losgText -losgDB -losgUtil -losg $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS) + +EXEC = osgforest + +INC += $(PRODUCER_INCLUDE_DIR) $(X_INC) +LDFLAGS += $(PRODUCER_LIB_DIR) + +include $(TOPDIR)/Make/makerules diff --git a/examples/osgshaderterrain/osgshaderterrain.cpp b/examples/osgshaderterrain/osgshaderterrain.cpp new file mode 100644 index 000000000..e3394a75d --- /dev/null +++ b/examples/osgshaderterrain/osgshaderterrain.cpp @@ -0,0 +1,795 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include + +#include + +#include + +// for the grid data.. +#include "../osghangglide/terrain_coords.h" + +// class to create the forest and manage the movement between various techniques. +class ForestTechniqueManager : public osg::Referenced +{ +public: + + ForestTechniqueManager() {} + + class Tree : public osg::Referenced + { + public: + + Tree(): + _color(255,255,255,255), + _width(1.0f), + _height(1.0f), + _type(0) {} + + Tree(const osg::Vec3& position, const osg::Vec4ub& color, float width, float height, unsigned int type): + _position(position), + _color(color), + _width(width), + _height(height), + _type(type) {} + + osg::Vec3 _position; + osg::Vec4ub _color; + float _width; + float _height; + unsigned int _type; + }; + + typedef std::vector< osg::ref_ptr > TreeList; + + class Cell : public osg::Referenced + { + public: + typedef std::vector< osg::ref_ptr > CellList; + + Cell():_parent(0) {} + Cell(osg::BoundingBox& bb):_parent(0), _bb(bb) {} + + void addCell(Cell* cell) { cell->_parent=this; _cells.push_back(cell); } + + void addTree(Tree* tree) { _trees.push_back(tree); } + + void addTrees(const TreeList& trees) { _trees.insert(_trees.end(),trees.begin(),trees.end()); } + + void computeBound(); + + bool contains(const osg::Vec3& position) const { return _bb.contains(position); } + + bool divide(unsigned int maxNumTreesPerCell=10); + + bool devide(bool xAxis, bool yAxis, bool zAxis); + + void bin(); + + + Cell* _parent; + osg::BoundingBox _bb; + CellList _cells; + TreeList _trees; + + }; + + float random(float min,float max) { return min + (max-min)*(float)rand()/(float)RAND_MAX; } + int random(int min,int max) { return min + (int)((float)(max-min)*(float)rand()/(float)RAND_MAX); } + + osg::Geode* createTerrain(const osg::Vec3& origin, const osg::Vec3& size); + + void createTreeList(osg::Node* terrain,const osg::Vec3& origin, const osg::Vec3& size,unsigned int numTreesToCreate,TreeList& trees); + + osg::Geometry* createOrthogonalQuadsNoColor( const osg::Vec3& pos, float w, float h ); + + osg::Node* createShaderGraph(Cell* cell,osg::StateSet* stateset); + + osg::Node* createScene(unsigned int numTreesToCreates); + + +}; + +// event handler to capture keyboard events and use them to advance the technique used for rendering +void ForestTechniqueManager::Cell::computeBound() +{ + _bb.init(); + for(CellList::iterator citr=_cells.begin(); + citr!=_cells.end(); + ++citr) + { + (*citr)->computeBound(); + _bb.expandBy((*citr)->_bb); + } + + for(TreeList::iterator titr=_trees.begin(); + titr!=_trees.end(); + ++titr) + { + _bb.expandBy((*titr)->_position); + } +} + +bool ForestTechniqueManager::Cell::divide(unsigned int maxNumTreesPerCell) +{ + + if (_trees.size()<=maxNumTreesPerCell) return false; + + computeBound(); + + float radius = _bb.radius(); + float divide_distance = radius*0.7f; + if (devide((_bb.xMax()-_bb.xMin())>divide_distance,(_bb.yMax()-_bb.yMin())>divide_distance,(_bb.zMax()-_bb.zMin())>divide_distance)) + { + // recusively divide the new cells till maxNumTreesPerCell is met. + for(CellList::iterator citr=_cells.begin(); + citr!=_cells.end(); + ++citr) + { + (*citr)->divide(maxNumTreesPerCell); + } + return true; + } + else + { + return false; + } +} + +bool ForestTechniqueManager::Cell::devide(bool xAxis, bool yAxis, bool zAxis) +{ + if (!(xAxis || yAxis || zAxis)) return false; + + if (_cells.empty()) + _cells.push_back(new Cell(_bb)); + + if (xAxis) + { + unsigned int numCellsToDivide=_cells.size(); + for(unsigned int i=0;i_bb); + + float xCenter = (orig_cell->_bb.xMin()+orig_cell->_bb.xMax())*0.5f; + orig_cell->_bb.xMax() = xCenter; + new_cell->_bb.xMin() = xCenter; + + _cells.push_back(new_cell); + } + } + + if (yAxis) + { + unsigned int numCellsToDivide=_cells.size(); + for(unsigned int i=0;i_bb); + + float yCenter = (orig_cell->_bb.yMin()+orig_cell->_bb.yMax())*0.5f; + orig_cell->_bb.yMax() = yCenter; + new_cell->_bb.yMin() = yCenter; + + _cells.push_back(new_cell); + } + } + + if (zAxis) + { + unsigned int numCellsToDivide=_cells.size(); + for(unsigned int i=0;i_bb); + + float zCenter = (orig_cell->_bb.zMin()+orig_cell->_bb.zMax())*0.5f; + orig_cell->_bb.zMax() = zCenter; + new_cell->_bb.zMin() = zCenter; + + _cells.push_back(new_cell); + } + } + + bin(); + + return true; + +} + +void ForestTechniqueManager::Cell::bin() +{ + // put trees in apprpriate cells. + TreeList treesNotAssigned; + for(TreeList::iterator titr=_trees.begin(); + titr!=_trees.end(); + ++titr) + { + Tree* tree = titr->get(); + bool assigned = false; + for(CellList::iterator citr=_cells.begin(); + citr!=_cells.end() && !assigned; + ++citr) + { + if ((*citr)->contains(tree->_position)) + { + (*citr)->addTree(tree); + assigned = true; + } + } + if (!assigned) treesNotAssigned.push_back(tree); + } + + // put the unassigned trees back into the original local tree list. + _trees.swap(treesNotAssigned); + + + // prune empty cells. + CellList cellsNotEmpty; + for(CellList::iterator citr=_cells.begin(); + citr!=_cells.end(); + ++citr) + { + if (!((*citr)->_trees.empty())) + { + cellsNotEmpty.push_back(*citr); + } + } + _cells.swap(cellsNotEmpty); + + +} + + +void ForestTechniqueManager::createTreeList(osg::Node* terrain,const osg::Vec3& origin, const osg::Vec3& size,unsigned int numTreesToCreate,TreeList& trees) +{ + + float max_TreeHeight = sqrtf(size.length2()/(float)numTreesToCreate); + float max_TreeWidth = max_TreeHeight*0.5f; + + float min_TreeHeight = max_TreeHeight*0.3f; + float min_TreeWidth = min_TreeHeight*0.5f; + + trees.reserve(trees.size()+numTreesToCreate); + + + for(unsigned int i=0;i_position.set(random(origin.x(),origin.x()+size.x()),random(origin.y(),origin.y()+size.y()),origin.z()); + tree->_color.set(random(128,255),random(128,255),random(128,255),255); + tree->_width = random(min_TreeWidth,max_TreeWidth); + tree->_height = random(min_TreeHeight,max_TreeHeight); + tree->_type = 0; + + if (terrain) + { + osgUtil::IntersectVisitor iv; + osg::ref_ptr segDown = new osg::LineSegment; + + segDown->set(tree->_position,tree->_position+osg::Vec3(0.0f,0.0f,size.z())); + iv.addLineSegment(segDown.get()); + + terrain->accept(iv); + + if (iv.hits()) + { + osgUtil::IntersectVisitor::HitList& hitList = iv.getHitList(segDown.get()); + if (!hitList.empty()) + { + osg::Vec3 ip = hitList.front().getWorldIntersectPoint(); + osg::Vec3 np = hitList.front().getWorldIntersectNormal(); + tree->_position = ip; + } + } + } + + trees.push_back(tree); + } +} + +osg::Geometry* ForestTechniqueManager::createOrthogonalQuadsNoColor( const osg::Vec3& pos, float w, float h) +{ + // set up the coords + osg::Vec3Array& v = *(new osg::Vec3Array(8)); + osg::Vec2Array& t = *(new osg::Vec2Array(8)); + + float rotation = random(0.0f,osg::PI/2.0f); + float sw = sinf(rotation)*w*0.5f; + float cw = cosf(rotation)*w*0.5f; + + v[0].set(pos.x()-sw,pos.y()-cw,pos.z()+0.0f); + v[1].set(pos.x()+sw,pos.y()+cw,pos.z()+0.0f); + v[2].set(pos.x()+sw,pos.y()+cw,pos.z()+h); + v[3].set(pos.x()-sw,pos.y()-cw,pos.z()+h); + + v[4].set(pos.x()-cw,pos.y()+sw,pos.z()+0.0f); + v[5].set(pos.x()+cw,pos.y()-sw,pos.z()+0.0f); + v[6].set(pos.x()+cw,pos.y()-sw,pos.z()+h); + v[7].set(pos.x()-cw,pos.y()+sw,pos.z()+h); + + t[0].set(0.0f,0.0f); + t[1].set(1.0f,0.0f); + t[2].set(1.0f,1.0f); + t[3].set(0.0f,1.0f); + + t[4].set(0.0f,0.0f); + t[5].set(1.0f,0.0f); + t[6].set(1.0f,1.0f); + t[7].set(0.0f,1.0f); + + osg::Geometry *geom = new osg::Geometry; + + geom->setVertexArray( &v ); + + geom->setTexCoordArray( 0, &t ); + + geom->addPrimitiveSet( new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,8) ); + + return geom; +} + +class ShaderGeometry : public osg::Drawable +{ + public: + ShaderGeometry() { setUseDisplayList(false); } + + /** Copy constructor using CopyOp to manage deep vs shallow copy.*/ + ShaderGeometry(const ShaderGeometry& ShaderGeometry,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY): + osg::Drawable(ShaderGeometry,copyop) {} + + META_Object(osg,ShaderGeometry) + + typedef std::vector PositionSizeList; + + virtual void drawImplementation(osg::State& state) const + { + for(PositionSizeList::const_iterator itr = _trees.begin(); + itr != _trees.end(); + ++itr) + { + glColor4fv(itr->ptr()); + _geometry->draw(state); + } + } + + virtual osg::BoundingBox computeBound() const + { + osg::BoundingBox geom_box = _geometry->getBound(); + osg::BoundingBox bb; + for(PositionSizeList::const_iterator itr = _trees.begin(); + itr != _trees.end(); + ++itr) + { + bb.expandBy(geom_box.corner(0)*(*itr)[3] + + osg::Vec3( (*itr)[0], (*itr)[1], (*itr)[2] )); + bb.expandBy(geom_box.corner(7)*(*itr)[3] + + osg::Vec3( (*itr)[0], (*itr)[1], (*itr)[2] )); + } + return bb; + } + + void setGeometry(osg::Geometry* geometry) + { + _geometry = geometry; + } + + void addTree(ForestTechniqueManager::Tree& tree) + { + _trees.push_back(osg::Vec4(tree._position.x(), tree._position.y(), tree._position.z(), tree._height)); + } + + osg::ref_ptr _geometry; + + PositionSizeList _trees; + + protected: + + virtual ~ShaderGeometry() {} + +}; + +osg::Geometry* shared_geometry = 0; + +osg::Node* ForestTechniqueManager::createShaderGraph(Cell* cell,osg::StateSet* stateset) +{ + if (shared_geometry==0) + { + shared_geometry = createOrthogonalQuadsNoColor(osg::Vec3(0.0f,0.0f,0.0f),1.0f,1.0f); + //shared_geometry->setUseDisplayList(false); + } + + + bool needGroup = !(cell->_cells.empty()); + bool needTrees = !(cell->_trees.empty()); + + osg::Geode* geode = 0; + osg::Group* group = 0; + + if (needTrees) + { + geode = new osg::Geode; + + ShaderGeometry* shader_geometry = new ShaderGeometry; + shader_geometry->setGeometry(shared_geometry); + + + for(TreeList::iterator itr=cell->_trees.begin(); + itr!=cell->_trees.end(); + ++itr) + { + Tree& tree = **itr; + shader_geometry->addTree(tree); + + } + + geode->setStateSet(stateset); + geode->addDrawable(shader_geometry); + } + + if (needGroup) + { + group = new osg::Group; + for(Cell::CellList::iterator itr=cell->_cells.begin(); + itr!=cell->_cells.end(); + ++itr) + { + group->addChild(createShaderGraph(itr->get(),stateset)); + } + + if (geode) group->addChild(geode); + + } + if (group) return group; + else return geode; +} + +osg::Node* ForestTechniqueManager::createScene(unsigned int numTreesToCreates) +{ + osg::Group* scene = new osg::Group; + + unsigned int numColumns = 38; + unsigned int numRows = 39; + unsigned int r; + unsigned int c; + + osg::Vec3 origin(0.0f,0.0f,0.0f); + osg::Vec3 size(1000.0f,1000.0f,250.0f); + osg::Vec3 scaleDown(1.0f/size.x(),1.0f/size.y(),1.0f/size.z()); + + // --------------------------------------- + // Set up a StateSet to texture the objects + // --------------------------------------- + osg::StateSet* stateset = new osg::StateSet(); + + + osg::Uniform* originUniform = new osg::Uniform("terrainOrigin",origin); + stateset->addUniform(originUniform); + + osg::Uniform* sizeUniform = new osg::Uniform("terrainSize",size); + stateset->addUniform(sizeUniform); + + osg::Uniform* scaleDownUniform = new osg::Uniform("terrainScaleDown",scaleDown); + stateset->addUniform(scaleDownUniform); + + osg::Uniform* terrainTextureSampler = new osg::Uniform("terrainTexture",0); + stateset->addUniform(terrainTextureSampler); + + osg::Uniform* baseTextureSampler = new osg::Uniform("baseTexture",1); + stateset->addUniform(baseTextureSampler); + + osg::Uniform* treeTextureSampler = new osg::Uniform("treeTexture",1); + stateset->addUniform(treeTextureSampler); + + + // compute z range of z values of grid data so we can scale it. + float min_z = FLT_MAX; + float max_z = -FLT_MAX; + for(r=0;rallocateImage(numColumns,numRows,1,GL_LUMINANCE, GL_FLOAT); + terrainImage->setInternalTextureFormat(GL_LUMINANCE_FLOAT32_ATI); + for(r=0;rdata(c,r))) = (vertex[r+c*numRows][2]-min_z)*scale_z; + } + } + + osg::Texture2D* terrainTexture = new osg::Texture2D; + terrainTexture->setImage(terrainImage); + terrainTexture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::NEAREST); + terrainTexture->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::NEAREST); + //terrainTexture->setResizeNonPowerOfTwoHint(true); + stateset->setTextureAttributeAndModes(0,terrainTexture,osg::StateAttribute::ON); + + + osg::Image* image = osgDB::readImageFile("Images/lz.rgb"); + if (image) + { + osg::Texture2D* texture = new osg::Texture2D; + + texture->setImage(image); + stateset->setTextureAttributeAndModes(1,texture,osg::StateAttribute::ON); + } + + { + std::cout<<"Creating terrain..."; + + osg::Geode* geode = new osg::Geode(); + geode->setStateSet( stateset ); + + + { + osg::Program* program = new osg::Program; + stateset->setAttribute(program); + +#if 1 + // use inline shaders + + /////////////////////////////////////////////////////////////////// + // vertex shader using just Vec4 coefficients + char vertexShaderSource[] = + "uniform float osg_FrameTime;\n" + "uniform sampler2D terrainTexture;\n" + "uniform vec3 terrainOrigin;\n" + "uniform vec3 terrainScaleDown;\n" + "\n" + "varying vec2 texcoord;\n" + "\n" + "void main(void)\n" + "{\n" + " texcoord = gl_Vertex.xy - terrainOrigin.xy;\n" + " texcoord.x *= terrainScaleDown.x;\n" + " texcoord.y *= terrainScaleDown.y;\n" + "\n" + " vec4 position;\n" + " position.x = gl_Vertex.x;\n" + " position.y = gl_Vertex.y;\n" + " position.z = texture2D(terrainTexture, texcoord).r;\n" + " \n" + " gl_Position = gl_ModelViewProjectionMatrix * position;\n" + " gl_FrontColor = vec4(1.0,1.0,1.0,1.0);\n" + "}\n"; + + ////////////////////////////////////////////////////////////////// + // fragment shader + // + char fragmentShaderSource[] = + "uniform sampler2D baseTexture; \n" + "varying vec2 texcoord;\n" + "\n" + "void main(void) \n" + "{\n" + " gl_FragColor = texture2D( baseTexture, texcoord); \n" + "}\n"; + + program->addShader(new osg::Shader(osg::Shader::VERTEX, vertexShaderSource)); + program->addShader(new osg::Shader(osg::Shader::FRAGMENT, fragmentShaderSource)); + +#else + + // get shaders from source + program->addShader(osg::Shader::readShaderFile(osg::Shader::VERTEX, osgDB::findDataFile("shaders/terrain.vert"))); + program->addShader(osg::Shader::readShaderFile(osg::Shader::FRAGMENT, osgDB::findDataFile("shaders/terrain.frag"))); + +#endif + + // get shaders from source + } + + + { + osg::Geometry* geometry = new osg::Geometry; + + osg::Vec3Array& v = *(new osg::Vec3Array(numColumns*numRows)); + osg::Vec4ubArray& color = *(new osg::Vec4ubArray(1)); + + color[0].set(255,255,255,255); + + float rowCoordDelta = size.y()/(float)(numRows-1); + float columnCoordDelta = size.x()/(float)(numColumns-1); + + float rowTexDelta = 1.0f/(float)(numRows-1); + float columnTexDelta = 1.0f/(float)(numColumns-1); + + osg::Vec3 pos = origin; + osg::Vec2 tex(0.0f,0.0f); + int vi=0; + for(r=0;rsetVertexArray(&v); + geometry->setColorArray(&color); + geometry->setColorBinding(osg::Geometry::BIND_OVERALL); + + for(r=0;raddPrimitiveSet(&drawElements); + int ei=0; + for(c=0;csetInitialBound(osg::BoundingBox(origin, origin+size)); + + geode->addDrawable(geometry); + + scene->addChild(geode); + } + } + + std::cout<<"done."< cell = new Cell; + cell->addTrees(trees); + cell->divide(); + std::cout<<"done."<setWrap( osg::Texture2D::WRAP_S, osg::Texture2D::CLAMP ); + tex->setWrap( osg::Texture2D::WRAP_T, osg::Texture2D::CLAMP ); + tex->setImage(osgDB::readImageFile("Images/tree0.rgba")); + + osg::StateSet *dstate = new osg::StateSet; + { + dstate->setTextureAttributeAndModes(1, tex, osg::StateAttribute::ON ); + + dstate->setAttributeAndModes( new osg::BlendFunc, osg::StateAttribute::ON ); + + osg::AlphaFunc* alphaFunc = new osg::AlphaFunc; + alphaFunc->setFunction(osg::AlphaFunc::GEQUAL,0.05f); + dstate->setAttributeAndModes( alphaFunc, osg::StateAttribute::ON ); + + dstate->setMode( GL_LIGHTING, osg::StateAttribute::OFF ); + + dstate->setRenderingHint( osg::StateSet::TRANSPARENT_BIN ); + } + + + { + osg::StateSet* stateset = new osg::StateSet; + + stateset->setTextureAttributeAndModes(0, tex, osg::StateAttribute::ON ); + stateset->setRenderingHint( osg::StateSet::TRANSPARENT_BIN ); + + { + osg::Program* program = new osg::Program; + stateset->setAttribute(program); + + // get shaders from source + program->addShader(osg::Shader::readShaderFile(osg::Shader::VERTEX, osgDB::findDataFile("shaders/forest2.vert"))); + program->addShader(osg::Shader::readShaderFile(osg::Shader::FRAGMENT, osgDB::findDataFile("shaders/forest2.frag"))); + } + + std::cout<<"Creating billboard based forest..."; + scene->addChild(createShaderGraph(cell.get(),stateset)); + + } +#endif + + return scene; +} + +int main( int argc, char **argv ) +{ + + // use an ArgumentParser object to manage the program arguments. + osg::ArgumentParser arguments(&argc,argv); + + // set up the usage document, in case we need to print out how to use this program. + arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates the osg::Shape classes."); + arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ..."); + arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information"); + arguments.getApplicationUsage()->addCommandLineOption("--trees ","Set the number of trees to create"); + + // construct the viewer. + osgProducer::Viewer viewer(arguments); + + float numTreesToCreates = 10000; + arguments.read("--trees",numTreesToCreates); + + // set up the value with sensible default event handlers. + viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS); + + osg::ref_ptr ttm = new ForestTechniqueManager; + + // get details on keyboard and mouse bindings used by the viewer. + viewer.getUsage(*arguments.getApplicationUsage()); + + // if user request help write it out to cout. + if (arguments.read("-h") || arguments.read("--help")) + { + arguments.getApplicationUsage()->write(std::cout); + return 1; + } + + // any option left unread are converted into errors to write out later. + arguments.reportRemainingOptionsAsUnrecognized(); + + // report any errors if they have occured when parsing the program aguments. + if (arguments.errors()) + { + arguments.writeErrorMessages(std::cout); + return 1; + } + + osg::Node* node = ttm->createScene((unsigned int)numTreesToCreates); + + // add model to viewer. + viewer.setSceneData( node ); + + // create the windows and run the threads. + viewer.realize(); + + while( !viewer.done() ) + { + // wait for all cull and draw threads to complete. + viewer.sync(); + + // update the scene by traversing it with the the update visitor which will + // call all node update callbacks and animations. + viewer.update(); + + // fire off the cull and draw traversals of the scene. + viewer.frame(); + + } + + // wait for all cull and draw threads to complete before exit. + viewer.sync(); + + return 0; +}