The light position is incorrectly calculated for shadow casting scenes
whose bounding box centre is not the origin. This is a one line fix.
Roger
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#include <osgShadow/ShadowTexture>
#include <osgShadow/ShadowedScene>
#include <osg/Notify>
#include <osg/ComputeBoundsVisitor>
#include <osg/io_utils>
using namespace osgShadow;
ShadowTexture::ShadowTexture():
_textureUnit(1)
{
}
ShadowTexture::ShadowTexture(const ShadowTexture& copy, const osg::CopyOp&
copyop):
ShadowTechnique(copy,copyop),
_textureUnit(copy._textureUnit)
{
}
void ShadowTexture::setTextureUnit(unsigned int unit)
{
_textureUnit = unit;
}
void ShadowTexture::init()
{
if (!_shadowedScene) return;
unsigned int tex_width = 512;
unsigned int tex_height = 512;
_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
_camera = new osg::Camera;
_camera->setClearColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
_camera->setCullCallback(new CameraCullCallback(this));
// 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);
//_camera->setRenderTargetImplementation(osg::Camera::SEPERATE_WINDOW);
// attach the texture and use it as the color buffer.
_camera->attach(osg::Camera::COLOR_BUFFER, _texture.get());
_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,osg::Vec4(0.0f,0.0f,0.0f,1.0f));
_material->setShininess(osg::Material::FRONT_AND_BACK,0.0f);
osg::StateSet* stateset = _camera->getOrCreateStateSet();
stateset->setAttribute(_material.get(),osg::StateAttribute::OVERRIDE);
}
{
_stateset = new osg::StateSet;
_stateset->setTextureAttributeAndModes(_textureUnit,_texture.get(),osg::StateAttribute::ON);
_stateset->setTextureMode(_textureUnit,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
_stateset->setTextureMode(_textureUnit,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
_stateset->setTextureMode(_textureUnit,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
_stateset->setTextureMode(_textureUnit,GL_TEXTURE_GEN_Q,osg::StateAttribute::ON);
_texgen = new osg::TexGen;
}
_dirty = false;
}
void ShadowTexture::update(osg::NodeVisitor& nv)
{
_shadowedScene->osg::Group::traverse(nv);
}
void ShadowTexture::cull(osgUtil::CullVisitor& cv)
{
// record the traversal mask on entry so we can reapply it later.
unsigned int traversalMask = cv.getTraversalMask();
osgUtil::RenderStage* orig_rs = cv.getRenderStage();
// do traversal of shadow casting scene which does not need to be decorated
by the shadow texture
{
cv.setTraversalMask( traversalMask &
getShadowedScene()->getCastsShadowTraversalMask()
);
_shadowedScene->osg::Group::traverse(cv);
}
// do traversal of shadow receiving scene which does need to be decorated
by the shadow texture
{
cv.pushStateSet(_stateset.get());
cv.setTraversalMask( traversalMask &
getShadowedScene()->getReceivesShadowTraversalMask() );
_shadowedScene->osg::Group::traverse(cv);
cv.popStateSet();
}
// need to compute view frustum for RTT camera.
// 1) get the light position
// 2) get the center and extents of the view frustum
const osg::Light* selectLight = 0;
osg::Vec4 lightpos;
osgUtil::PositionalStateContainer::AttrMatrixList& aml =
orig_rs->getPositionalStateContainer()->getAttrMatrixList();
for(osgUtil::PositionalStateContainer::AttrMatrixList::iterator itr =
aml.begin();
itr != aml.end();
++itr)
{
const osg::Light* light = dynamic_cast<const
osg::Light*>(itr->first.get());
if (light)
{
osg::RefMatrix* matrix = itr->second.get();
if (matrix) lightpos = light->getPosition() * (*matrix);
else lightpos = light->getPosition();
selectLight = light;
}
}
osg::Matrix eyeToWorld;
eyeToWorld.invert(*cv.getModelViewMatrix());
lightpos = lightpos * eyeToWorld;
if (selectLight)
{
// get the bounds of the model.
osg::ComputeBoundsVisitor
cbbv(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN);
cbbv.setTraversalMask(getShadowedScene()->getCastsShadowTraversalMask());
_shadowedScene->osg::Group::traverse(cbbv);
osg::BoundingBox bb = cbbv.getBoundingBox();
if (lightpos[3]!=0.0)
{
osg::Vec3 position(lightpos.x(), lightpos.y(), lightpos.z());
float centerDistance = (position-bb.center()).length();
float znear = centerDistance-bb.radius();
float zfar = centerDistance+bb.radius();
float zNearRatio = 0.001f;
if (znear<zfar*zNearRatio) znear = zfar*zNearRatio;
float top = (bb.radius()/centerDistance)*znear;
float right = top;
_camera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
_camera->setProjectionMatrixAsFrustum(-right,right,-top,top,znear,zfar);
_camera->setViewMatrixAsLookAt(position,bb.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);
_texgen->setMode(osg::TexGen::EYE_LINEAR);
_texgen->setPlanesFromMatrix(MVPT);
}
else
{
// make an orthographic projection
osg::Vec3 lightDir(lightpos.x(), lightpos.y(), lightpos.z());
lightDir.normalize();
// set the position far away along the light direction
osg::Vec3 position = bb.center() + lightDir * bb.radius() * 2;
float centerDistance = (position-bb.center()).length();
float znear = centerDistance-bb.radius();
float zfar = centerDistance+bb.radius();
float zNearRatio = 0.001f;
if (znear<zfar*zNearRatio) znear = zfar*zNearRatio;
float top = bb.radius();
float right = top;
_camera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
_camera->setProjectionMatrixAsOrtho(-right, right, -top, top,
znear, zfar);
_camera->setViewMatrixAsLookAt(position,bb.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);
_texgen->setMode(osg::TexGen::EYE_LINEAR);
_texgen->setPlanesFromMatrix(MVPT);
}
cv.setTraversalMask( traversalMask &
getShadowedScene()->getCastsShadowTraversalMask()
);
// do RTT camera traversal
_camera->accept(cv);
orig_rs->getPositionalStateContainer()->addPositionedTextureAttribute(_textureUnit,
cv.getModelViewMatrix(), _texgen.get());
}
// reapply the original traversal mask
cv.setTraversalMask( traversalMask );
}
void ShadowTexture::cleanSceneGraph()
{
}
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