Prior to this change, if the receiving geometry has texture coordinates
outside the 0..1 depth map range, the geometry is rendered with ~0.5 correct
intensity due to contribution from the (zero intensity) texture edge. With
this change, that geometry is rendered at the correct intensity.
You can see the problem in the osgshadow example if you hack the ModelThree
class to create a base/box with much larger horizontal extent.
This change was made based on the 2.0 source. However, if you need the
change based off of current source, just look for the two "CLAMP_TO_EDGE"
lines that I added, and add them to current source. It's a trivial change.
Paul Martz
Skew Matrix Software LLC
http://www.skew-matrix.com <http://www.skew-matrix.com/>
303 859 9466
/* -*-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/ShadowMap>
#include <osgShadow/ShadowedScene>
#include <osg/Notify>
#include <osg/ComputeBoundsVisitor>
#include <osg/PolygonOffset>
#include <osg/CullFace>
#include <osg/io_utils>
using namespace osgShadow;
//////////////////////////////////////////////////////////////////
// fragment shader
//
static const char fragmentShaderSource_noBaseTexture[] =
"uniform sampler2DShadow shadowTexture; \n"
"uniform vec2 ambientBias; \n"
"\n"
"void main(void) \n"
"{ \n"
" gl_FragColor = gl_Color * (ambientBias.x + shadow2DProj(
shadowTexture, gl_TexCoord[0] ) * ambientBias.y); \n"
"}\n";
//////////////////////////////////////////////////////////////////
// fragment shader
//
static const char fragmentShaderSource_withBaseTexture[] =
"uniform sampler2D baseTexture; \n"
"uniform sampler2DShadow shadowTexture; \n"
"uniform vec2 ambientBias; \n"
"\n"
"void main(void) \n"
"{ \n"
" vec4 color = gl_Color * texture2D( baseTexture, gl_TexCoord[0].xy );
\n"
" gl_FragColor = color * (ambientBias.x + shadow2DProj( shadowTexture,
gl_TexCoord[1] ) * ambientBias.y); \n"
"}\n";
ShadowMap::ShadowMap():
_textureUnit(1),
_ambientBias(0.3f,1.2f)
{
}
ShadowMap::ShadowMap(const ShadowMap& copy, const osg::CopyOp& copyop):
ShadowTechnique(copy,copyop),
_textureUnit(copy._textureUnit),
_ambientBias(copy._ambientBias)
{
}
void ShadowMap::setTextureUnit(unsigned int unit)
{
_textureUnit = unit;
}
void ShadowMap::setAmbientBias(const osg::Vec2& ambientBias)
{
_ambientBias = ambientBias;
}
void ShadowMap::init()
{
if (!_shadowedScene) return;
unsigned int tex_width = 1024;
unsigned int tex_height = 1024;
_texture = new osg::Texture2D;
_texture->setTextureSize(tex_width, tex_height);
_texture->setInternalFormat(GL_DEPTH_COMPONENT);
_texture->setShadowComparison(true);
_texture->setShadowTextureMode(osg::Texture2D::LUMINANCE);
_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_EDGE);
_texture->setWrap(osg::Texture2D::WRAP_T,osg::Texture2D::CLAMP_TO_EDGE);
// set up the render to texture camera.
{
// create the camera
_camera = new osg::Camera;
_camera->setCullCallback(new CameraCullCallback(this));
_camera->setClearMask(GL_DEPTH_BUFFER_BIT);
//_camera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
_camera->setClearColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
_camera->setComputeNearFarMode(osg::Camera::DO_NOT_COMPUTE_NEAR_FAR);
// 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::DEPTH_BUFFER, _texture.get());
osg::StateSet* stateset = _camera->getOrCreateStateSet();
float factor = 0.0f;
float units = 1.0f;
osg::ref_ptr<osg::PolygonOffset> polygon_offset = new
osg::PolygonOffset;
polygon_offset->setFactor(factor);
polygon_offset->setUnits(units);
stateset->setAttribute(polygon_offset.get(), osg::StateAttribute::ON |
osg::StateAttribute::OVERRIDE);
stateset->setMode(GL_POLYGON_OFFSET_FILL, osg::StateAttribute::ON |
osg::StateAttribute::OVERRIDE);
osg::ref_ptr<osg::CullFace> cull_face = new osg::CullFace;
cull_face->setMode(osg::CullFace::FRONT);
stateset->setAttribute(cull_face.get(), osg::StateAttribute::ON |
osg::StateAttribute::OVERRIDE);
stateset->setMode(GL_CULL_FACE, osg::StateAttribute::ON |
osg::StateAttribute::OVERRIDE);
}
{
_stateset = new osg::StateSet;
_stateset->setTextureAttributeAndModes(_textureUnit,_texture.get(),osg::StateAttribute::ON
| osg::StateAttribute::OVERRIDE);
_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;
#if 1
osg::Program* program = new osg::Program;
_stateset->setAttribute(program);
if (_textureUnit==0)
{
osg::Shader* fragment_shader = new
osg::Shader(osg::Shader::FRAGMENT, fragmentShaderSource_noBaseTexture);
program->addShader(fragment_shader);
osg::Uniform* shadowTextureSampler = new
osg::Uniform("shadowTexture",(int)_textureUnit);
_stateset->addUniform(shadowTextureSampler);
}
else
{
osg::Shader* fragment_shader = new
osg::Shader(osg::Shader::FRAGMENT, fragmentShaderSource_withBaseTexture);
program->addShader(fragment_shader);
osg::Uniform* baseTextureSampler = new
osg::Uniform("baseTexture",0);
_stateset->addUniform(baseTextureSampler);
osg::Uniform* shadowTextureSampler = new
osg::Uniform("shadowTexture",(int)_textureUnit);
_stateset->addUniform(shadowTextureSampler);
}
osg::Uniform* ambientBias = new
osg::Uniform("ambientBias",_ambientBias);
_stateset->addUniform(ambientBias);
#endif
}
_dirty = false;
}
void ShadowMap::update(osg::NodeVisitor& nv)
{
_shadowedScene->osg::Group::traverse(nv);
}
void ShadowMap::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 recieving scene which does need to be decorated
by the shadow map
{
cv.pushStateSet(_stateset.get());
_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 = lightDir * bb.radius() * 20;
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 ShadowMap::cleanSceneGraph()
{
}
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