OpenSceneGraph/examples/osgshadowtexture/CreateShadowedScene.cpp

225 lines
8.6 KiB
C++

/* OpenSceneGraph example, osgshadowtexture.
*
* 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/Texture2D>
#include <osg/Material>
#include <osg/LightSource>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/ShapeDrawable>
#include <osg/Camera>
#include <osg/TexGenNode>
#include <osg/Notify>
#include <osg/io_utils>
#include "CreateShadowedScene.h"
using namespace osg;
class UpdateCameraAndTexGenCallback : public osg::NodeCallback
{
public:
UpdateCameraAndTexGenCallback(const osg::Vec3& position, osg::Camera* Camera, osg::TexGenNode* texgenNode):
_position(position),
_Camera(Camera),
_texgenNode(texgenNode)
{
}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
// first update subgraph to make sure objects are all moved into postion
traverse(node,nv);
// now compute the camera's view and projection matrix to point at the shadower (the camera's children)
osg::BoundingSphere bs;
for(unsigned int i=0; i<_Camera->getNumChildren(); ++i)
{
bs.expandBy(_Camera->getChild(i)->getBound());
}
if (!bs.valid())
{
osg::notify(osg::WARN) << "bb invalid"<<_Camera.get()<<std::endl;
return;
}
float centerDistance = (_position-bs.center()).length();
float znear = centerDistance-bs.radius();
float zfar = centerDistance+bs.radius();
float zNearRatio = 0.001f;
if (znear<zfar*zNearRatio) znear = zfar*zNearRatio;
float top = (bs.radius()/centerDistance)*znear;
float right = top;
_Camera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
_Camera->setProjectionMatrixAsFrustum(-right,right,-top,top,znear,zfar);
_Camera->setViewMatrixAsLookAt(_position,bs.center(),osg::Vec3(0.0f,1.0f,0.0f));
// compute the matrix which takes a vertex from local coords into tex coords
// will use this later to specify osg::TexGen..
osg::Matrix MVPT = _Camera->getViewMatrix() *
_Camera->getProjectionMatrix() *
osg::Matrix::translate(1.0,1.0,1.0) *
osg::Matrix::scale(0.5f,0.5f,0.5f);
_texgenNode->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
_texgenNode->getTexGen()->setPlanesFromMatrix(MVPT);
}
protected:
virtual ~UpdateCameraAndTexGenCallback() {}
osg::Vec3 _position;
osg::ref_ptr<osg::Camera> _Camera;
osg::ref_ptr<osg::TexGenNode> _texgenNode;
};
osg::Group* createShadowedScene(osg::Node* shadower,osg::Node* shadowed,const osg::Vec3& lightPosition,float radius,unsigned int unit)
{
osg::Group* group = new osg::Group;
// add light source
{
osg::LightSource* lightSource = new osg::LightSource;
lightSource->getLight()->setPosition(osg::Vec4(lightPosition,1.0f));
lightSource->getLight()->setLightNum(0);
group->addChild(lightSource);
osg::Geode* lightgeode = new osg::Geode;
lightgeode->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
lightgeode->addDrawable(new osg::ShapeDrawable(new osg::Sphere(lightPosition,radius)));
group->addChild(lightgeode);
}
osg::Vec4 ambientLightColor(0.2,0.2f,0.2f,1.0f);
// add the shadower and shadowed.
group->addChild(shadower);
group->addChild(shadowed);
unsigned int tex_width = 512;
unsigned int tex_height = 512;
osg::Texture2D* texture = new osg::Texture2D;
texture->setTextureSize(tex_width, tex_height);
texture->setInternalFormat(GL_RGB);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
texture->setWrap(osg::Texture2D::WRAP_S,osg::Texture2D::CLAMP_TO_BORDER);
texture->setWrap(osg::Texture2D::WRAP_T,osg::Texture2D::CLAMP_TO_BORDER);
texture->setBorderColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
// set up the render to texture camera.
{
// create the camera
osg::Camera* camera = new osg::Camera;
camera->setClearColor(osg::Vec4(1.0f,1.0f,1.0f,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(osg::Camera::FRAME_BUFFER_OBJECT);
// attach the texture and use it as the color buffer.
camera->attach(osg::Camera::COLOR_BUFFER, texture);
// add subgraph to render
camera->addChild(shadower);
osg::StateSet* stateset = camera->getOrCreateStateSet();
// make the material black for a shadow.
osg::Material* material = new osg::Material;
material->setAmbient(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,0.0f,1.0f));
material->setDiffuse(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,0.0f,1.0f));
material->setEmission(osg::Material::FRONT_AND_BACK,ambientLightColor);
material->setShininess(osg::Material::FRONT_AND_BACK,0.0f);
stateset->setAttribute(material,osg::StateAttribute::OVERRIDE);
group->addChild(camera);
// create the texgen node to project the tex coords onto the subgraph
osg::TexGenNode* texgenNode = new osg::TexGenNode;
texgenNode->setTextureUnit(unit);
group->addChild(texgenNode);
// set an update callback to keep moving the camera and tex gen in the right direction.
group->setUpdateCallback(new UpdateCameraAndTexGenCallback(lightPosition, camera, texgenNode));
}
// set the shadowed subgraph so that it uses the texture and tex gen settings.
{
osg::StateSet* stateset = shadowed->getOrCreateStateSet();
stateset->setTextureAttributeAndModes(unit,texture,osg::StateAttribute::ON);
stateset->setTextureMode(unit,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
stateset->setTextureMode(unit,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
stateset->setTextureMode(unit,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
stateset->setTextureMode(unit,GL_TEXTURE_GEN_Q,osg::StateAttribute::ON);
}
// set hud to render shadow texture, just for interest
{
osg::Geode* geode = new osg::Geode;
osg::Geometry* geom = osg::createTexturedQuadGeometry(osg::Vec3(0,0,0),osg::Vec3(100.0,0.0,0.0),osg::Vec3(0.0,100.0,0.0));
geom->getOrCreateStateSet()->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
geom->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
geode->addDrawable(geom);
osg::Camera* camera = new osg::Camera;
// set the projection matrix
camera->setProjectionMatrix(osg::Matrix::ortho2D(0,100,0,100));
// set the view matrix
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setViewMatrix(osg::Matrix::identity());
camera->setViewport(50,50,100,100);
// only clear the depth buffer
camera->setClearMask(GL_DEPTH_BUFFER_BIT);
// draw subgraph after main camera view.
camera->setRenderOrder(osg::Camera::POST_RENDER);
camera->addChild(geode);
group->addChild(camera);
}
return group;
}