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Updates to the osgprerender code. Still doesn't do anything interesting yet..

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This commit is contained in:
Robert Osfield 2002-07-09 13:31:50 +00:00
parent 3ab727713d
commit 68540f5fb1
3 changed files with 12 additions and 268 deletions
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2
src/Demos/osgprerender/Makefile
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@ -10,6 +10,6 @@ INSTFILES = \
$(CXXFILES)\ $(CXXFILES)\
Makefile.inst=Makefile Makefile.inst=Makefile
EXEC = osgreflect EXEC = osgprerender
include $(TOPDIR)/Make/makerules include $(TOPDIR)/Make/makerules

2
src/Demos/osgprerender/Makefile.inst
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@ -6,6 +6,6 @@ CXXFILES =\
LIBS += $(OSG_LIBS) $(GLUT_LIB) $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS) LIBS += $(OSG_LIBS) $(GLUT_LIB) $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS)
EXEC = osgreflect EXEC = osgprerender
include $(TOPDIR)/Make/makerules include $(TOPDIR)/Make/makerules

276
src/Demos/osgprerender/osgprerender.cpp
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@ -20,81 +20,11 @@
#include <osgGLUT/glut> #include <osgGLUT/glut>
#include <osgGLUT/Viewer> #include <osgGLUT/Viewer>
osg::Node* createPreRenderSubGraph(osg::Node* subgraph)
//
// A simple demo demonstrating planer reflections using multiple renderings
// of a subgraph, overriding of state attribures and use of the stencil buffer.
//
// The multipass system implemented here is a variation if Mark Kilgard's
// paper "Improving Shadows and Reflections via the Stencil Buffer" which
// can be found on the developer parts of the NVidia web site.
//
// The variations comes from the fact that the mirrors stencil values
// are done on the first pass, rather than the second as in Mark's paper.
// The second pass is now Mark's first pass - drawing the unreflected scene,
// but also unsets the stencil buffer. This variation stops the unreflected
// world poking through the mirror to be seen in the final rendering and
// also obscures the world correctly when on the reverse side of the mirror.
// Although there is still some unresolved issue with the clip plane needing
// to be flipped when looking at the reverse side of the mirror. Niether
// of these issues are mentioned in the Mark's paper, but trip us up when
// we apply them.
osg::StateSet* createMirrorTexturedState(const std::string& filename)
{ {
osg::StateSet* dstate = new osg::StateSet; // ok we havn't done anything yet, but this is where the funky code
dstate->setMode(GL_CULL_FACE,osg::StateAttribute::OFF); // will go :)
return NULL;
// set up the texture.
osg::Image* image = osgDB::readImageFile(filename.c_str());
if (image)
{
osg::Texture* texture = new osg::Texture;
texture->setImage(image);
dstate->setAttributeAndModes(texture,osg::StateAttribute::ON);
}
return dstate;
}
osg::Drawable* createMirrorSurface(float xMin,float xMax,float yMin,float yMax,float z)
{
// set up the drawstate.
// set up the Geometry.
osg::Geometry* geom = new osg::Geometry;
osg::Vec3Array* coords = new osg::Vec3Array(4);
(*coords)[0].set(xMin,yMax,z);
(*coords)[1].set(xMin,yMin,z);
(*coords)[2].set(xMax,yMin,z);
(*coords)[3].set(xMax,yMax,z);
geom->setVertexArray(coords);
osg::Vec3Array* norms = new osg::Vec3Array(1);
(*norms)[0].set(0.0f,0.0f,1.0f);
geom->setNormalArray(norms);
geom->setNormalBinding(osg::Geometry::BIND_OVERALL);
osg::Vec2Array* tcoords = new osg::Vec2Array(4);
(*tcoords)[0].set(0.0f,1.0f);
(*tcoords)[1].set(0.0f,0.0f);
(*tcoords)[2].set(1.0f,0.0f);
(*tcoords)[3].set(1.0f,1.0f);
geom->setTexCoordArray(0,tcoords);
osg::Vec4Array* colours = new osg::Vec4Array(1);
(*colours)[0].set(1.0f,1.0f,1.0,1.0f);
geom->setColorArray(colours);
geom->setColorBinding(osg::Geometry::BIND_OVERALL);
geom->addPrimitive(osgNew osg::DrawArrays(osg::Primitive::QUADS,0,4));
return geom;
} }
void write_usage(std::ostream& out,const std::string& name) void write_usage(std::ostream& out,const std::string& name)
@ -167,207 +97,21 @@ int main( int argc, char **argv )
return 1; return 1;
} }
// create a transform to spin the model.
osg::Transform* loadedModelTransform = new osg::Transform; osg::Transform* loadedModelTransform = new osg::Transform;
loadedModelTransform->addChild(loadedModel); loadedModelTransform->addChild(loadedModel);
// calculate where to place the mirror according to the osg::NodeCallback* nc = new osgUtil::TransformCallback(loadedModelTransform->getBound().center(),osg::Vec3(0.0f,0.0f,1.0f),osg::inDegrees(45.0f));
// loaded models bounding sphere. loadedModelTransform->setAppCallback(nc);
const osg::BoundingSphere& bs = loadedModelTransform->getBound();
float width_factor = 1.5; osg::Group* rootNode = new osg::Group();
float height_factor = 0.3; rootNode->addChild(loadedModelTransform);
rootNode->addChild(createPreRenderSubGraph(loadedModelTransform));
float xMin = bs.center().x()-bs.radius()*width_factor;
float xMax = bs.center().x()+bs.radius()*width_factor;
float yMin = bs.center().y()-bs.radius()*width_factor;
float yMax = bs.center().y()+bs.radius()*width_factor;
float z = bs.center().z()-bs.radius()*height_factor;
// create a textured, transparent node at the appropriate place.
osg::Drawable* mirror = createMirrorSurface(xMin,xMax,yMin,yMax,z);
osg::Group* rootNode = new osg::Group;
// make sure that the global color mask exists.
osg::ColorMask* rootColorMask = new osg::ColorMask;
rootColorMask->setMask(true,true,true,true);
// set up depth to be inherited by the rest of the scene unless
// overrideen. this is overridden in bin 3.
osg::Depth* rootDepth = new osg::Depth;
rootDepth->setFunction(osg::Depth::LESS);
rootDepth->setRange(0.0,1.0);
osg::StateSet* rootStateSet = new osg::StateSet();
rootStateSet->setAttribute(rootColorMask);
rootStateSet->setAttribute(rootDepth);
rootNode->setStateSet(rootStateSet);
// bin1 - set up the stencil values and depth for mirror.
{
// set up the stencil ops so that the stencil buffer get set at
// the mirror plane
osg::Stencil* stencil = new osg::Stencil;
stencil->setFunction(osg::Stencil::ALWAYS,1,~0);
stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::REPLACE);
// switch off the writing to the color bit planes.
osg::ColorMask* colorMask = new osg::ColorMask;
colorMask->setMask(false,false,false,false);
osg::StateSet* statesetBin1 = new osg::StateSet();
statesetBin1->setRenderBinDetails(1,"RenderBin");
statesetBin1->setMode(GL_CULL_FACE,osg::StateAttribute::OFF);
statesetBin1->setAttributeAndModes(stencil,osg::StateAttribute::ON);
statesetBin1->setAttribute(colorMask);
// set up the mirror geode.
osg::Geode* geode = new osg::Geode;
geode->addDrawable(mirror);
geode->setStateSet(statesetBin1);
rootNode->addChild(geode);
}
// bin one - draw scene without mirror or reflection, unset
// stencil values where scene is infront of mirror and hence
// occludes the mirror.
{
osg::Stencil* stencil = new osg::Stencil;
stencil->setFunction(osg::Stencil::ALWAYS,0,~0);
stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::REPLACE);
osg::StateSet* statesetBin2 = new osg::StateSet();
statesetBin2->setRenderBinDetails(2,"RenderBin");
statesetBin2->setAttributeAndModes(stencil,osg::StateAttribute::ON);
osg::Group* groupBin2 = new osg::Group();
groupBin2->setStateSet(statesetBin2);
groupBin2->addChild(loadedModelTransform);
rootNode->addChild(groupBin2);
}
// bin3 - set up the depth to the furthest depth value
{
// set up the stencil ops so that only operator on this mirrors stencil value.
osg::Stencil* stencil = new osg::Stencil;
stencil->setFunction(osg::Stencil::EQUAL,1,~0);
stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::KEEP);
// switch off the writing to the color bit planes.
osg::ColorMask* colorMask = new osg::ColorMask;
colorMask->setMask(false,false,false,false);
// set up depth so all writing to depth goes to maximum depth.
osg::Depth* depth = new osg::Depth;
depth->setFunction(osg::Depth::ALWAYS);
depth->setRange(1.0,1.0);
osg::StateSet* statesetBin3 = new osg::StateSet();
statesetBin3->setRenderBinDetails(3,"RenderBin");
statesetBin3->setMode(GL_CULL_FACE,osg::StateAttribute::OFF);
statesetBin3->setAttributeAndModes(stencil,osg::StateAttribute::ON);
statesetBin3->setAttribute(colorMask);
statesetBin3->setAttribute(depth);
// set up the mirror geode.
osg::Geode* geode = new osg::Geode;
geode->addDrawable(mirror);
geode->setStateSet(statesetBin3);
rootNode->addChild(geode);
}
// bin4 - draw the reflection.
{
// now create the 'reflection' of the loaded model by applying
// create a Transform which flips the loaded model about the z axis
// relative to the mirror node, the loadedModel is added to the
// Transform so now appears twice in the scene, but is shared so there
// is negligable memory overhead. Also use an osg::StateSet
// attached to the Transform to override the face culling on the subgraph
// to prevert an 'inside' out view of the reflected model.
// set up the stencil ops so that only operator on this mirrors stencil value.
osg::Stencil* stencil = new osg::Stencil;
stencil->setFunction(osg::Stencil::EQUAL,1,~0);
stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::KEEP);
// this clip plane removes any of the scene which when mirror would
// poke through the mirror. However, this clip plane should really
// flip sides once the eye point goes to the back of the mirror...
osg::ClipPlane* clipplane = new osg::ClipPlane;
clipplane->setClipPlane(osg::Vec4(0.0f,0.0f,-1.0f,z));
clipplane->setClipPlaneNum(0);
osg::StateSet* dstate = new osg::StateSet;
dstate->setRenderBinDetails(4,"RenderBin");
dstate->setMode(GL_CULL_FACE,osg::StateAttribute::OVERRIDE_OFF);
dstate->setAttributeAndModes(stencil,osg::StateAttribute::ON);
dstate->setAttributeAndModes(clipplane,osg::StateAttribute::ON);
osg::Transform* dcs = new osg::Transform;
dcs->setStateSet(dstate);
dcs->preMult(osg::Matrix::translate(0.0f,0.0f,-z)*
osg::Matrix::scale(1.0f,1.0f,-1.0f)*
osg::Matrix::translate(0.0f,0.0f,z));
dcs->addChild(loadedModelTransform);
rootNode->addChild(dcs);
}
// bin5 - draw the textured mirror and blend it with the reflection.
{
// set up depth so all writing to depth goes to maximum depth.
osg::Depth* depth = new osg::Depth;
depth->setFunction(osg::Depth::ALWAYS);
osg::Stencil* stencil = new osg::Stencil;
stencil->setFunction(osg::Stencil::EQUAL,1,~0);
stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::ZERO);
// set up additive blending.
osg::Transparency* trans = new osg::Transparency;
trans->setFunction(osg::Transparency::ONE,osg::Transparency::ONE);
osg::StateSet* statesetBin5 = createMirrorTexturedState("Images/tank.rgb");
statesetBin5->setRenderBinDetails(5,"RenderBin");
statesetBin5->setMode(GL_CULL_FACE,osg::StateAttribute::OFF);
statesetBin5->setAttributeAndModes(stencil,osg::StateAttribute::ON);
statesetBin5->setAttributeAndModes(trans,osg::StateAttribute::ON);
statesetBin5->setAttribute(depth);
// set up the mirror geode.
osg::Geode* geode = new osg::Geode;
geode->addDrawable(mirror);
geode->setStateSet(statesetBin5);
rootNode->addChild(geode);
}
// add model to the viewer. // add model to the viewer.
viewer.addViewport( rootNode ); viewer.addViewport( rootNode );
osg::NodeCallback* nc = new osgUtil::TransformCallback(loadedModelTransform->getBound().center(),osg::Vec3(0.0f,0.0f,1.0f),osg::inDegrees(45.0f));
loadedModelTransform->setAppCallback(nc);
// register trackball, flight and drive. // register trackball, flight and drive.
viewer.registerCameraManipulator(new osgGA::TrackballManipulator); viewer.registerCameraManipulator(new osgGA::TrackballManipulator);