8fd4bbe510
light material rather than ambient, this allows it to bypass any of the osg::Light values and control the resulting shadow colour more directly.
277 lines
9.3 KiB
C++
277 lines
9.3 KiB
C++
#include <osg/Texture2D>
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#include <osg/TexGen>
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#include <osg/Material>
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#include <osg/LightSource>
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#include <osg/Geode>
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#include <osg/ShapeDrawable>
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#include <osgUtil/CullVisitor>
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#include <osgUtil/RenderToTextureStage>
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#include "CreateShadowedScene.h"
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using namespace osg;
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class CreateShadowTextureCullCallback : public osg::NodeCallback
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{
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public:
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CreateShadowTextureCullCallback(osg::Node* shadower,const osg::Vec3& position, const osg::Vec4& ambientLightColor, unsigned int textureUnit):
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_shadower(shadower),
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_position(position),
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_ambientLightColor(ambientLightColor),
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_unit(textureUnit),
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_shadowState(new osg::StateSet),
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_shadowedState(new osg::StateSet)
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{
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_texture = new osg::Texture2D;
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_texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
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_texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
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_texture->setWrap(osg::Texture2D::WRAP_S,osg::Texture2D::CLAMP_TO_BORDER);
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_texture->setWrap(osg::Texture2D::WRAP_T,osg::Texture2D::CLAMP_TO_BORDER);
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_texture->setBorderColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
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}
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virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
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{
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osgUtil::CullVisitor* cullVisitor = dynamic_cast<osgUtil::CullVisitor*>(nv);
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if (cullVisitor && (_texture.valid() && _shadower.valid()))
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{
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doPreRender(*node,*cullVisitor);
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}
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else
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{
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// must traverse the shadower
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traverse(node,nv);
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}
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}
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protected:
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void doPreRender(osg::Node& node, osgUtil::CullVisitor& cv);
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osg::ref_ptr<osg::Node> _shadower;
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osg::ref_ptr<osg::Texture2D> _texture;
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osg::Vec3 _position;
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osg::Vec4 _ambientLightColor;
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unsigned int _unit;
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osg::ref_ptr<osg::StateSet> _shadowState;
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osg::ref_ptr<osg::StateSet> _shadowedState;
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// we need this to get round the order dependance
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// of eye linear tex gen...
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class MyTexGen : public TexGen
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{
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public:
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void setMatrix(const osg::Matrix& matrix)
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{
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_matrix = matrix;
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}
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virtual void apply(osg::State& state) const
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{
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glPushMatrix();
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glLoadMatrix(_matrix.ptr());
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TexGen::apply(state);
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glPopMatrix();
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}
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osg::Matrix _matrix;
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};
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};
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void CreateShadowTextureCullCallback::doPreRender(osg::Node& node, osgUtil::CullVisitor& cv)
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{
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const osg::BoundingSphere& bs = _shadower->getBound();
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if (!bs.valid())
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{
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osg::notify(osg::WARN) << "bb invalid"<<_shadower.get()<<std::endl;
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return;
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}
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// create the render to texture stage.
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osg::ref_ptr<osgUtil::RenderToTextureStage> rtts = new osgUtil::RenderToTextureStage;
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// set up lighting.
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// currently ignore lights in the scene graph itself..
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// will do later.
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osgUtil::RenderStage* previous_stage = cv.getCurrentRenderBin()->_stage;
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// set up the background color and clear mask.
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rtts->setClearColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
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rtts->setClearMask(previous_stage->getClearMask());
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// set up to charge the same RenderStageLighting is the parent previous stage.
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rtts->setRenderStageLighting(previous_stage->getRenderStageLighting());
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// record the render bin, to be restored after creation
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// of the render to text
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osgUtil::RenderBin* previousRenderBin = cv.getCurrentRenderBin();
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// set the current renderbin to be the newly created stage.
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cv.setCurrentRenderBin(rtts.get());
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float centerDistance = (_position-bs.center()).length();
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float znear = centerDistance-bs.radius();
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float zfar = centerDistance+bs.radius();
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float zNearRatio = 0.001f;
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if (znear<zfar*zNearRatio) znear = zfar*zNearRatio;
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// 2:1 aspect ratio as per flag geomtry below.
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float top = (bs.radius()/centerDistance)*znear;
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float right = top;
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// set up projection.
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osg::RefMatrix* projection = new osg::RefMatrix;
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projection->makeFrustum(-right,right,-top,top,znear,zfar);
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cv.pushProjectionMatrix(projection);
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osg::RefMatrix* matrix = new osg::RefMatrix;
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matrix->makeLookAt(_position,bs.center(),osg::Vec3(0.0f,1.0f,0.0f));
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osg::Matrix MV = cv.getModelViewMatrix();
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// compute the matrix which takes a vertex from local coords into tex coords
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// will use this later to specify osg::TexGen..
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osg::Matrix MVPT =
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*matrix *
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*projection *
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osg::Matrix::translate(1.0,1.0,1.0) *
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osg::Matrix::scale(0.5f,0.5f,0.5f);
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cv.pushModelViewMatrix(matrix);
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// make the material black for a shadow.
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osg::Material* material = new osg::Material;
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material->setAmbient(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,0.0f,1.0f));
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material->setDiffuse(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,0.0f,1.0f));
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material->setEmission(osg::Material::FRONT_AND_BACK,_ambientLightColor);
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material->setShininess(osg::Material::FRONT_AND_BACK,0.0f);
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_shadowState->setAttribute(material,osg::StateAttribute::OVERRIDE);
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cv.pushStateSet(_shadowState.get());
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{
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// traverse the shadower
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_shadower->accept(cv);
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}
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cv.popStateSet();
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// restore the previous model view matrix.
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cv.popModelViewMatrix();
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// restore the previous model view matrix.
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cv.popProjectionMatrix();
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// restore the previous renderbin.
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cv.setCurrentRenderBin(previousRenderBin);
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if (rtts->_renderGraphList.size()==0 && rtts->_bins.size()==0)
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{
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// getting to this point means that all the shadower has been
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// culled by small feature culling or is beyond LOD ranges.
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return;
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}
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int height = 256;
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int width = 256;
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const osg::Viewport& viewport = *cv.getViewport();
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// offset the impostor viewport from the center of the main window
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// viewport as often the edges of the viewport might be obscured by
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// other windows, which can cause image/reading writing problems.
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int center_x = viewport.x()+viewport.width()/2;
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int center_y = viewport.y()+viewport.height()/2;
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osg::Viewport* new_viewport = new osg::Viewport;
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new_viewport->setViewport(center_x-width/2,center_y-height/2,width,height);
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rtts->setViewport(new_viewport);
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_shadowState->setAttribute(new_viewport);
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// and the render to texture stage to the current stages
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// dependancy list.
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cv.getCurrentRenderBin()->_stage->addToDependencyList(rtts.get());
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// if one exist attach texture to the RenderToTextureStage.
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if (_texture.valid()) rtts->setTexture(_texture.get());
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// set up the stateset to decorate the shadower with the shadow texture
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// with the appropriate tex gen coords.
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MyTexGen* texgen = new MyTexGen;
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texgen->setMatrix(MV);
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texgen->setMode(osg::TexGen::EYE_LINEAR);
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texgen->setPlane(osg::TexGen::S,osg::Plane(MVPT(0,0),MVPT(1,0),MVPT(2,0),MVPT(3,0)));
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texgen->setPlane(osg::TexGen::T,osg::Plane(MVPT(0,1),MVPT(1,1),MVPT(2,1),MVPT(3,1)));
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texgen->setPlane(osg::TexGen::R,osg::Plane(MVPT(0,2),MVPT(1,2),MVPT(2,2),MVPT(3,2)));
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texgen->setPlane(osg::TexGen::Q,osg::Plane(MVPT(0,3),MVPT(1,3),MVPT(2,3),MVPT(3,3)));
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_shadowedState->setTextureAttributeAndModes(_unit,_texture.get(),osg::StateAttribute::ON);
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_shadowedState->setTextureAttribute(_unit,texgen);
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_shadowedState->setTextureMode(_unit,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
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_shadowedState->setTextureMode(_unit,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
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_shadowedState->setTextureMode(_unit,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
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_shadowedState->setTextureMode(_unit,GL_TEXTURE_GEN_Q,osg::StateAttribute::ON);
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cv.pushStateSet(_shadowedState.get());
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// must traverse the shadower
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traverse(&node,&cv);
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cv.popStateSet();
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}
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// set up a light source with the shadower and shodower subgraphs below it
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// with the appropriate callbacks set up.
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osg::Group* createShadowedScene(osg::Node* shadower,osg::Node* shadowed,const osg::Vec3& lightPosition,float radius,unsigned int textureUnit)
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{
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osg::LightSource* lightgroup = new osg::LightSource;
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osg::Light* light = new osg::Light;
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light->setPosition(osg::Vec4(lightPosition,1.0f));
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light->setLightNum(0);
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lightgroup->setLight(light);
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osg::Vec4 ambientLightColor(0.2,0.2f,0.2f,1.0f);
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// add the shadower
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lightgroup->addChild(shadower);
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// add the shadowed with the callback to generate the shadow texture.
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shadowed->setCullCallback(new CreateShadowTextureCullCallback(shadower,lightPosition,ambientLightColor,textureUnit));
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lightgroup->addChild(shadowed);
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osg::Geode* lightgeode = new osg::Geode;
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lightgeode->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
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lightgeode->addDrawable(new osg::ShapeDrawable(new osg::Sphere(lightPosition,radius)));
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lightgroup->addChild(lightgeode);
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return lightgroup;
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}
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