[osg-users] Using Ortho2D projection camera under OpenSceneGraph PRE_RENDER camera
Robert Osfield
robert.osfield at gmail.com
Sat Jan 21 06:48:51 PST 2017
Hi Martin,
I have am only popping online briefly so a just a quick response.
What makes you think that the pre render camera is not being drawn?
Robert.
On 20 January 2017 at 22:12, Malcolm Pigott
<osg.malcolm at hydrogenrocks.me.uk> wrote:
> I have a scene in OpenSceneGraph which has a "normal" 3D content overlaid with content in an Ortho2D projection. This works OK.
>
> I am now trying to render this scene to a texture (via a Frame Buffer Object) and am working with the osgPreRender example. Below is some code derived from that example which has a 2D overlay which is shown when the scene is drawn normally, but not (seemingly) drawn when rendered to a texture using setRenderOrder(osg::Camera::PRE_RENDER).
>
> This is using OpenSceneGraph 3.4.0 and VS2015 Update 2.
>
>
> Code:
>
> /* OpenSceneGraph example, osgprerender.
> *
> * Permission is hereby granted, free of charge, to any person obtaining a copy
> * of this software and associated documentation files (the "Software"), to deal
> * in the Software without restriction, including without limitation the rights
> * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> * copies of the Software, and to permit persons to whom the Software is
> * furnished to do so, subject to the following conditions:
> *
> * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> * THE SOFTWARE.
> */
>
> #include <osg/GLExtensions>
> #include <osg/Node>
> #include <osg/Geometry>
> #include <osg/Notify>
> #include <osg/MatrixTransform>
> #include <osg/Texture2D>
> #include <osg/TextureRectangle>
> #include <osg/Stencil>
> #include <osg/ColorMask>
> #include <osg/Depth>
> #include <osg/Billboard>
> #include <osg/Material>
> #include <osg/AnimationPath>
> #include <osg/LineWidth>
>
> #include <osgGA/TrackballManipulator>
> #include <osgGA/FlightManipulator>
> #include <osgGA/DriveManipulator>
>
> #include <osgUtil/SmoothingVisitor>
>
> #include <osgDB/Registry>
> #include <osgDB/ReadFile>
> #include <osgDB/WriteFile>
>
> #include <osgViewer/Viewer>
> #include <osgViewer/ViewerEventHandlers>
>
> #include <iostream>
>
> // call back which creates a deformation field to oscillate the model.
> class MyGeometryCallback :
> public osg::Drawable::UpdateCallback,
> public osg::Drawable::AttributeFunctor
> {
> public:
>
> MyGeometryCallback(const osg::Vec3& o,
> const osg::Vec3& x, const osg::Vec3& y, const osg::Vec3& z,
> double period, double xphase, double amplitude) :
> _firstCall(true),
> _startTime(0.0),
> _time(0.0),
> _period(period),
> _xphase(xphase),
> _amplitude(amplitude),
> _origin(o),
> _xAxis(x),
> _yAxis(y),
> _zAxis(z) {}
>
> virtual void update(osg::NodeVisitor* nv, osg::Drawable* drawable)
> {
> // OpenThreads::Thread::microSleep( 1000 );
>
> const osg::FrameStamp* fs = nv->getFrameStamp();
> double simulationTime = fs->getSimulationTime();
> if (_firstCall)
> {
> _firstCall = false;
> _startTime = simulationTime;
> }
>
> _time = simulationTime - _startTime;
>
> drawable->accept(*this);
> drawable->dirtyBound();
>
> osg::Geometry* geometry = dynamic_cast<osg::Geometry*>(drawable);
> if (geometry)
> {
> osgUtil::SmoothingVisitor::smooth(*geometry);
> }
>
> }
>
> virtual void apply(osg::Drawable::AttributeType type, unsigned int count, osg::Vec3* begin)
> {
> if (type == osg::Drawable::VERTICES)
> {
> const float TwoPI = 2.0f*osg::PI;
> const float phase = -_time / _period;
>
> osg::Vec3* end = begin + count;
> for (osg::Vec3* itr = begin; itr<end; ++itr)
> {
> osg::Vec3 dv(*itr - _origin);
> osg::Vec3 local(dv*_xAxis, dv*_yAxis, dv*_zAxis);
>
> local.z() = local.x()*_amplitude*
> sinf(TwoPI*(phase + local.x()*_xphase));
>
> (*itr) = _origin +
> _xAxis*local.x() +
> _yAxis*local.y() +
> _zAxis*local.z();
> }
> }
> }
>
> bool _firstCall;
>
> double _startTime;
> double _time;
>
> double _period;
> double _xphase;
> float _amplitude;
>
> osg::Vec3 _origin;
> osg::Vec3 _xAxis;
> osg::Vec3 _yAxis;
> osg::Vec3 _zAxis;
>
> };
>
> osg::Node* createPreRenderSubGraph(osg::Node* subgraph,
> unsigned tex_width, unsigned tex_height,
> osg::Camera::RenderTargetImplementation renderImplementation,
> bool useTextureRectangle,
> unsigned int samples, unsigned int colorSamples)
> {
> if (!subgraph) return 0;
>
> // create a group to contain the flag and the pre rendering camera.
> osg::Group* parent = new osg::Group;
>
> // texture to render to and to use for rendering of flag.
> osg::Texture* texture = 0;
> {
> osg::TextureRectangle* textureRect = new osg::TextureRectangle;
> textureRect->setTextureSize(tex_width, tex_height);
> textureRect->setInternalFormat(GL_RGBA);
> textureRect->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR);
> textureRect->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR);
>
> texture = textureRect;
> }
>
> // first create the geometry of the flag of which to view.
> {
> // create the to visualize.
> osg::Geometry* polyGeom = new osg::Geometry();
>
> polyGeom->setName("PolyGeom");
>
> polyGeom->setDataVariance(osg::Object::DYNAMIC);
> polyGeom->setSupportsDisplayList(false);
>
> osg::Vec3 origin(0.0f, 0.0f, 0.0f);
> osg::Vec3 xAxis(1.0f, 0.0f, 0.0f);
> osg::Vec3 yAxis(0.0f, 0.0f, 1.0f);
> osg::Vec3 zAxis(0.0f, -1.0f, 0.0f);
> float height = 100.0f;
> float width = 200.0f;
> int noSteps = 20;
>
> osg::Vec3Array* vertices = new osg::Vec3Array;
> osg::Vec3 bottom = origin;
> osg::Vec3 top = origin; top.z() += height;
> osg::Vec3 dv = xAxis*(width / ((float)(noSteps - 1)));
>
> osg::Vec2Array* texcoords = new osg::Vec2Array;
>
> // note, when we use TextureRectangle we have to scale the tex coords up to compensate.
> osg::Vec2 bottom_texcoord(0.0f, 0.0f);
> osg::Vec2 top_texcoord(0.0f, useTextureRectangle ? tex_height : 1.0f);
> osg::Vec2 dv_texcoord((useTextureRectangle ? tex_width : 1.0f) / (float)(noSteps - 1), 0.0f);
>
> for (int i = 0; i<noSteps; ++i)
> {
> vertices->push_back(top);
> vertices->push_back(bottom);
> top += dv;
> bottom += dv;
>
> texcoords->push_back(top_texcoord);
> texcoords->push_back(bottom_texcoord);
> top_texcoord += dv_texcoord;
> bottom_texcoord += dv_texcoord;
> }
>
>
> // pass the created vertex array to the points geometry object.
> polyGeom->setVertexArray(vertices);
>
> polyGeom->setTexCoordArray(0, texcoords);
>
> osg::Vec4Array* colors = new osg::Vec4Array;
> colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
> polyGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
>
> polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUAD_STRIP, 0, vertices->size()));
>
> // new we need to add the texture to the Drawable, we do so by creating a
> // StateSet to contain the Texture StateAttribute.
> osg::StateSet* stateset = new osg::StateSet;
>
> stateset->setTextureAttributeAndModes(0, texture, osg::StateAttribute::ON);
>
> polyGeom->setStateSet(stateset);
>
> polyGeom->setUpdateCallback(new MyGeometryCallback(origin, xAxis, yAxis, zAxis, 1.0, 1.0 / width, 0.2f));
>
> osg::Geode* geode = new osg::Geode();
> geode->addDrawable(polyGeom);
>
> parent->addChild(geode);
>
> }
>
>
> // then create the camera node to do the render to texture
> {
> osg::Camera* camera = new osg::Camera;
>
> // set up the background color and clear mask.
> camera->setClearColor(osg::Vec4(0.1f, 0.1f, 0.3f, 1.0f));
> camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
>
> const osg::BoundingSphere& bs = subgraph->getBound();
> if (!bs.valid())
> {
> return subgraph;
> }
>
> float znear = 1.0f*bs.radius();
> float zfar = 3.0f*bs.radius();
>
> // 2:1 aspect ratio as per flag geometry below.
> float proj_top = 0.25f*znear;
> float proj_right = 0.5f*znear;
>
> znear *= 0.9f;
> zfar *= 1.1f;
>
> // set up projection.
> camera->setProjectionMatrixAsFrustum(-proj_right, proj_right, -proj_top, proj_top, znear, zfar);
>
> // set view
> camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
> camera->setViewMatrixAsLookAt(bs.center() - osg::Vec3(0.0f, 2.0f, 0.0f)*bs.radius(), bs.center(), osg::Vec3(0.0f, 0.0f, 1.0f));
>
> // set viewport
> camera->setViewport(0, 0, tex_width, tex_height);
>
> // set the camera to render before the main camera.
> camera->setRenderOrder(osg::Camera::PRE_RENDER);
>
> // tell the camera to use OpenGL frame buffer object where supported.
> camera->setRenderTargetImplementation(renderImplementation);
>
> // attach the texture and use it as the color buffer.
> camera->attach(osg::Camera::COLOR_BUFFER, texture, 0, 0, false, samples, colorSamples);
>
> // add subgraph to render
> camera->addChild(subgraph);
>
> parent->addChild(camera);
>
> }
>
> return parent;
> }
>
> osg::Node *createNormalScene(osgViewer::Viewer &Viewer)
> {
> auto topNodeOfNormalScene = new osg::Group();
> {
> auto normal3DScene = new osg::Group();
> {
> normal3DScene->addChild(osgDB::readNodeFile("cessna.osgt")); // 3D example
> topNodeOfNormalScene->addChild(normal3DScene);
> }
> auto overlayLikeA2DHUD = new osg::Group();
> {
> auto overlayCamera = new osg::Camera();
> overlayCamera->getOrCreateStateSet()->setGlobalDefaults();
> double _orthoLeft = 0.0;
> double _orthoRight = 1280.0;
> double _orthoBottom = 0.0;
> double _orthoTop = 1024.0;
> {
> // Create the symbology camera
>
> overlayCamera->setName("OverlayViewCamera");
> overlayCamera->setProjectionMatrixAsOrtho2D(_orthoLeft, _orthoRight, _orthoBottom, _orthoTop);
> overlayCamera->setDataVariance(osg::Object::DYNAMIC); // gets updated when the screen size changes.
> //_symbologyCamera->setRenderOrder(osg::Camera::POST_RENDER);
> overlayCamera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
> overlayCamera->setClearMask(GL_DEPTH_BUFFER_BIT);
> overlayCamera->setViewport(new osg::Viewport(0.0, 0.0, (_orthoRight - _orthoLeft), (_orthoTop - _orthoBottom)));
> }
> {
> auto Geometry = new osg::Geometry();
> {
> Geometry->setName("2DTie");
> double Left = 100.0;
> double Bottom = 100.0;
> double Right = 924.0;
> double Top = 1180.0;
> // tie
> osg::Vec3Array *vertexArray = new osg::Vec3Array();
> vertexArray->push_back(osg::Vec3d(Left, Bottom, 0.0));
> vertexArray->push_back(osg::Vec3d(Right, Bottom, 0.0));
> vertexArray->push_back(osg::Vec3d(Left, Top, 0.0));
> vertexArray->push_back(osg::Vec3d(Right, Top, 0.0));
> Geometry->setVertexArray(vertexArray);
> osg::Vec3 colors[] = { { 1.0f, 1.0f, 1.0f } };
> osg::Vec3Array *colorArray = new osg::Vec3Array(1, colors);
> Geometry->setColorArray(colorArray, osg::Array::BIND_OVERALL);
> Geometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP, 0, vertexArray->size()));
> Geometry->getOrCreateStateSet()->setAttributeAndModes(new osg::LineWidth(2.0f), osg::StateAttribute::ON);
> }
> auto Geode = new osg::Geode();
> Geode->addDrawable(Geometry);
> auto Group = new osg::Group();
> Group->addChild(Geode);
> overlayCamera->addChild(Group);
> }
> overlayLikeA2DHUD->addChild(overlayCamera);
> //Viewer.addSlave(_symbologyCamera, false);
> topNodeOfNormalScene->addChild(overlayLikeA2DHUD);
> }
> }
> return topNodeOfNormalScene;
> }
>
> 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 pre rendering of scene to a texture, and then apply this texture to geometry.");
> arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName() + " [options] filename ...");
> arguments.getApplicationUsage()->addCommandLineOption("-h or --help", "Display this information");
> arguments.getApplicationUsage()->addCommandLineOption("--fbo", "Use Frame Buffer Object for render to texture, where supported.");
> arguments.getApplicationUsage()->addCommandLineOption("--fb", "Use FrameBuffer for render to texture.");
> arguments.getApplicationUsage()->addCommandLineOption("--pbuffer", "Use Pixel Buffer for render to texture, where supported.");
> arguments.getApplicationUsage()->addCommandLineOption("--window", "Use a separate Window for render to texture.");
> arguments.getApplicationUsage()->addCommandLineOption("--width", "Set the width of the render to texture.");
> arguments.getApplicationUsage()->addCommandLineOption("--height", "Set the height of the render to texture.");
> arguments.getApplicationUsage()->addCommandLineOption("--image", "Render to an image, then apply a post draw callback to it, and use this image to update a texture.");
> arguments.getApplicationUsage()->addCommandLineOption("--texture-rectangle", "Use osg::TextureRectangle for doing the render to texture to.");
>
> // construct the viewer.
> osgViewer::Viewer viewer(arguments);
>
> // add stats
> viewer.addEventHandler(new osgViewer::StatsHandler());
>
> // add the record camera path handler
> viewer.addEventHandler(new osgViewer::RecordCameraPathHandler);
>
> // add the threading handler
> viewer.addEventHandler(new osgViewer::ThreadingHandler());
>
> // if user request help write it out to cout.
> if (arguments.read("-h") || arguments.read("--help"))
> {
> arguments.getApplicationUsage()->write(std::cout);
> return 1;
> }
>
> unsigned int tex_width = 1280;
> unsigned int tex_height = 1024;
> unsigned int samples = 0;
> unsigned int colorSamples = 0;
>
> while (arguments.read("--width", tex_width)) {}
> while (arguments.read("--height", tex_height)) {}
>
> osg::Camera::RenderTargetImplementation renderImplementation = osg::Camera::FRAME_BUFFER_OBJECT;
>
> while (arguments.read("--fbo")) { renderImplementation = osg::Camera::FRAME_BUFFER_OBJECT; }
> while (arguments.read("--pbuffer")) { renderImplementation = osg::Camera::PIXEL_BUFFER; }
> while (arguments.read("--pbuffer-rtt")) { renderImplementation = osg::Camera::PIXEL_BUFFER_RTT; }
> while (arguments.read("--fb")) { renderImplementation = osg::Camera::FRAME_BUFFER; }
> while (arguments.read("--window")) { renderImplementation = osg::Camera::SEPARATE_WINDOW; }
> while (arguments.read("--fbo-samples", samples)) {}
> while (arguments.read("--color-samples", colorSamples)) {}
>
> bool useTextureRectangle = true;
> while (arguments.read("--texture-rectangle")) { useTextureRectangle = true; }
>
> // load the nodes from the commandline arguments.
> osg::Node* loadedModel = osgDB::readNodeFiles(arguments);
>
> // if not loaded assume no arguments passed in, try use default mode instead.
> if (!loadedModel) loadedModel = createNormalScene(viewer); // osgDB::readNodeFile("cessna.osgt");
>
> if (!loadedModel)
> {
> return 1;
> }
>
> bool PreRender = true; // alter via debugger
> if (PreRender)
> {
> // create a transform to spin the model.
> osg::MatrixTransform* loadedModelTransform = new osg::MatrixTransform;
> loadedModelTransform->addChild(loadedModel);
>
> osg::NodeCallback* nc = new osg::AnimationPathCallback(loadedModelTransform->getBound().center(), osg::Vec3(0.0f, 0.0f, 1.0f), osg::inDegrees(45.0f));
> loadedModelTransform->setUpdateCallback(nc);
>
> osg::Group* rootNode = new osg::Group();
> rootNode->addChild(createPreRenderSubGraph(loadedModelTransform, tex_width, tex_height, renderImplementation, useTextureRectangle, samples, colorSamples));
>
> bool WriteOutNodeFile = false; // alter via debugger
> if (WriteOutNodeFile)
> {
> osgDB::writeNodeFile(*rootNode, "PreRenderExample.osgt"); // view using Notepad++ and LUA language mode (for example).
> }
>
> // add model to the viewer.
> viewer.setSceneData(rootNode);
> }
> else
> {
> auto camera = viewer.getCamera();
> // set up the background color and clear mask.
> camera->setClearColor(osg::Vec4(0.1f, 0.1f, 0.3f, 1.0f));
> camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
>
> viewer.setSceneData(loadedModel);
> }
>
> return viewer.run();
> }
>
>
>
>
> Many thanks for any guidance.
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=70025#70025
>
>
>
>
> Attachments:
> http://forum.openscenegraph.org//files/ortho2dinprerender_895.cpp
>
>
> _______________________________________________
> osg-users mailing list
> osg-users at lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
More information about the osg-users
mailing list