Hi,
Thank you for the code snippet. Looking it over I see two differences from my
implementation which have been giving me a headache. These are not necessarily
related to camera render orders so it might be appropriate to send these as
separate threads.
First difference from your code and mine is the lack of you needing to allocate
an image to the render in order to place the texture within a stateset:
Code:
//... initializing texture, attached to camera'a color buffer, etc
[b]osg::Image* image = new osg::Image;
image->allocateImage(width, height, 1, GL_RGBA, GL_FLOAT);
_texture->setImage(0, image);[/b]
//... initializing geometry and stateset
stateset->setTextureAttributeAndModes(0, _texture, osg::StateAttribute::ON);
In my experience, this is required or else a seg fault occurs when the draw
traversal references "_texture". I am confused on how you are able to pass the
texture without allocating an image inside the texture. I have included a code
snippet below to fully clarify what I see occurring.
The second difference is your code uses non power of 2 dimensions for your
texture to be rendered by your camera. Whenever I have tried to do this I have
run into the error :
"Warning: detected OpenGL error 'invalid value' after RenderBin::draw(,)"
during every draw call to the geometry containing the texture
Here is my code snippet with the problematic line in bold
Code:
//Will need to set the texture size to the size of the viewport, it is not
right now
_texture = new osg::Texture2D();
{
_texture->setTextureSize(width, height);
_texture->setInternalFormat(GL_RGBA);
_texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::NEAREST);
_texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::NEAREST);
}
//set up the camera
{
// set up the render to camera attributes.
setClearMask( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
setClearColor(osg::Vec4(0.0f,0.0f,0.0f,1.0f));
// set viewport
setViewport(0,0, width, height);
setRenderOrder(osg::Camera::PRE_RENDER);
setRenderTargetImplementation(osg::Camera::FRAME_BUFFER,
osg::Camera::FRAME_BUFFER);
// attach the texture and use it as the color buffer. this will render the
depth buffer to the texture.
//this should not be needed
//############################## Problem 1 ##########################
osg::Image* image = new osg::Image;
image->allocateImage(width, height, 1, GL_RGBA, GL_FLOAT);
_texture->setImage(0, image);
//############################## Problem 1 ##########################
//render the depth buffer to the texture
attach(osg::Camera::COLOR_BUFFER0, _texture, 0, 0, false, 8, 8);
}
osg::Geometry* polyGeom = new osg::Geometry();
polyGeom->setDataVariance( osg::Object::DYNAMIC );
polyGeom->setSupportsDisplayList(false);
float x0 = -5;
float y0 = 0;
float w = 10;
float h = 10;
osg::Vec3Array* verts = new osg::Vec3Array;
verts->push_back(osg::Vec3(x0, 0, y0));
verts->push_back(osg::Vec3(x0 + w, 0, y0));
verts->push_back(osg::Vec3(x0 + w, 0, y0 + h));
verts->push_back(osg::Vec3(x0, 0, y0 + h));
polyGeom->setVertexArray(verts);
polyGeom->addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::QUADS,0,verts->size()));
osg::Vec2Array* texcoords = new osg::Vec2Array;
texcoords->push_back(osg::Vec2(0, 0));
texcoords->push_back(osg::Vec2(1, 0));
texcoords->push_back(osg::Vec2(1, 1));
texcoords->push_back(osg::Vec2(0, 1));
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);
polyGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
osg::StateSet* stateset = new osg::StateSet;
//########################### problem 2 ############################
//without allocating an image to the texture this line will cause a seg fault
stateset->setTextureAttributeAndModes(0, _texture, osg::StateAttribute::ON);
//###############################################################
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
polyGeom->setStateSet(stateset);
osg::Geode* geode = new osg::Geode();
geode->addDrawable(polyGeom);
return geode;
Thank you for taking time to go over the code and looking at this post
Cheers,
Ross
------------------
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http://forum.openscenegraph.org/viewtopic.php?p=20071#20071
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