Hi,
I have to distort a scene to be consistent with the video that is diplayed
behind the scene (basically some augmented reality) and then render everything
in an image. I used 2 camera (not slaves) and a texture to distort the scene
but the shadows are not rendered that way. I found the only way to get the
shadows was to have slaves camera so I am now using 2 slaves camera and a
texture to do it and I get a white texture.
I used several osg examples to test it before using it in my project
(osgshadow, osgdistortion, osgscreencapture) and I am able to render a
distorted animated scene into an image (from the osgshadow, I integrated all I
needed to render the distorted texture into an image).
Here is the code of the function that does that distorted rendering.
Code:
osg::ref_ptr<osg::GraphicsContext::Traits> traits = new
osg::GraphicsContext::Traits;
traits->x = 0;
traits->y = 0;
traits->width = 800;
traits->height = 600;
traits->red = 8;
traits->green = 8;
traits->blue = 8;
traits->alpha = 0;
traits->windowDecoration = false;
traits->pbuffer = true;
traits->doubleBuffer = true;
traits->sharedContext = 0;
osg::ref_ptr<osg::GraphicsContext> gc =
osg::GraphicsContext::createGraphicsContext(traits.get());
unsigned int texWidth = 800;
unsigned int texHeight = 600;
osg::Texture2D* texture = new osg::Texture2D;
texture->setTextureSize(texWidth, texHeight);
texture->setInternalFormat(GL_RGBA);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
{
osg::Camera* camera = new osg::Camera;
camera->setGraphicsContext(gc.get());
camera->setViewport(0,0,texWidth,texHeight);
camera->setDrawBuffer(GL_FRONT);
camera->setReadBuffer(GL_FRONT);
camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
camera->attach(osg::Camera::COLOR_BUFFER, texture, 0);
_viewer->addSlave(camera, osg::Matrixd(), osg::Matrixd());
}
{
osg::Geometry* polyGeom = new osg::Geometry();
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,1.0f,0.0f);
float height = (float)texHeight;
float width = (float)texWidth;;
int noSteps = 20;
float maxU = 1.0;
float maxV = 1.0;
osg::Vec3Array* vertices = new osg::Vec3Array;
osg::Vec2Array* texcoords = new osg::Vec2Array;
osg::Vec4Array* colors = new osg::Vec4Array;
polyGeom->setVertexArray(vertices);
polyGeom->setTexCoordArray(0,texcoords);
unsigned int rows = 20, cols = 20;
float rowSize = height / (float)rows;
float colSize = width / (float)cols;
double px, py, u, v;
double * dist = _arManager->getDistFactor();
for(unsigned int r = 0; r < rows; r++)
{
for(unsigned int c = 0; c <= cols; c++)
{
distortPoint(dist, colSize, rowSize, r, c, &px, &py);
vertices->push_back(osg::Vec3(px, py, 0.0f));
u = (c / (float)(cols)) * maxU;
v = (r / (float)(rows)) * maxV;
texcoords->push_back(osg::Vec2(u, v));
distortPoint(dist, colSize, rowSize, r+1, c, &px, &py);
vertices->push_back(osg::Vec3(px, py, 0.0f));
u = (c / (float)(cols)) * maxU;
v = ((r + 1) / (float)(rows)) * maxV;
texcoords->push_back(osg::Vec2(u, v));
}
polyGeom->addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::QUAD_STRIP, r * 2 * (cols+1), 2 * (cols+1)));
}
osg::StateSet* stateset = polyGeom->getOrCreateStateSet();
stateset->setTextureAttributeAndModes(0, texture, osg::StateAttribute::ON);
stateset->setMode(GL_LIGHTING, osg::StateAttribute::ON |
osg::StateAttribute::PROTECTED);
stateset->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
stateset->setMode(GL_BLEND, osg::StateAttribute::OVERRIDE |
osg::StateAttribute::ON);
osg::Geode * geode = new osg::Geode();
geode->addDrawable(polyGeom);
// set up the camera to render the textured quad
osg::Camera * camera = new osg::Camera;
camera->setGraphicsContext(gc.get());
camera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
camera->setClearColor(clearColour);
camera->setViewport(0,0,texWidth,texHeight);
camera->setDrawBuffer(GL_BACK);
camera->setReadBuffer(GL_BACK);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setAllowEventFocus(false);
camera->setProjectionMatrixAsOrtho2D(0, texWidth, 0, texHeight);
camera->setViewMatrix(osg::Matrix::identity());
camera->addChild(geode);
WindowCaptureCallback * wcc = new
WindowCaptureCallback(WindowCaptureCallback::DOUBLE_PBO,
WindowCaptureCallback::END_FRAME, GL_BACK);
camera->setFinalDrawCallback(wcc);
_cd = wcc->getContextData(gc.get());
_viewer->addSlave(camera, osg::Matrixd(), osg::Matrixd(), false);
}
I found out that removing the last attribute when I add the second slave camera
give me back the video + scene, but there is nothing distorted. Also, when the
texture is composed by only one quad (so no distortion computed) and I add the
second camera with the last parameter set to false, I can see all the scene (no
white texture).
Maybe I am missing some important thing about slave camera but I can't find any
solution.
Any hint on this weird problem is welcome :)
Thank you!
Cheers,
Zarra
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=37219#37219
_______________________________________________
osg-users mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
