Hi Robert, I'm working now on integrating the new osgViewer and osg 2.x into the simulator of our company, and as a result I am moving to using osgShadow::ShadowMap in place of the old code that I refactored to use with osg 1.2, before the first iterations of the NodeKit.
I will extend the osg class to integrate with the company's physics and
viewer, and I am trying to keep to a minimum the overlap between the osg
code and the derived class.
Therefore there are a couple of things that seem simpler to change or
add-in to osgShadow::ShadowMap, and this way the class gets some
additions, if they are warranted.
As an example I added functions to get/set a Vec2 for the x/y size of
the depth texture used. (I attached the changed files)
There are three other points that I will need to work with:
1. updating the camera & TexGen during cull()
One part here is to change the way the light is selected, one option
is to keep a reference to the intended osg::Light, the current code will
use the last light in the list of the RenderStage.
Another is to set a different ways to update, the current way is to
use the bounding box of the entire scene. Another style that I found
useful is to use a given reference point and radius, for example so that
the shadows can follow a vehicle without losing resolution as it moves
about a terrain, or use the parameters of a given SpotLight.
I see that ShadowTechnique defines ShadowTechnique::CameraCullCallback,
but I did not see if it is ever used, is it intended for this kind of
usage ? Then what would be the best way of using it ?
2. custom GLSL shaders
Need to be able to set / get custom programs for rendering the
scene. I can see this done by either passing an std::string for
vertex/fragment shaders, or by passing osg::Shader/Program.
3. Uniform variables for controlling rendering
I suggest to have a set of standard uniforms ( a standard name like
for the other ones used by osg ) to help with implementation of custom
shaders. The values that are immediately needed are baseTexture,
shadowTexture, ambientBias, and the texture unit used for shadowing
coordinates, to access the appropriate gl_TexCoord[].
When using the nodekit on complex scenes with multiple lights, that
can be enabled/disabled at run-time, I found that I needed to also use a
uniform to disable shadow application when the shadow casting light is
turned off, this can also be used on a per-object basis to turn off
application of shadows on some parts of the scene. The GL number of the
shadow-casting light is another important value when a different light
is used to cast shadows.
I'm eager to get your opinion on this.
Cheers
Mihai Radu
/* -*-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),
_textureSize(1024,1024)
{
}
ShadowMap::ShadowMap(const ShadowMap& copy, const osg::CopyOp& copyop):
ShadowTechnique(copy,copyop),
_textureUnit(copy._textureUnit),
_ambientBias(copy._ambientBias),
_textureSize(copy._textureSize)
{
}
void ShadowMap::setTextureUnit(unsigned int unit)
{
_textureUnit = unit;
}
void ShadowMap::setAmbientBias(const osg::Vec2& ambientBias)
{
_ambientBias = ambientBias;
}
void ShadowMap::setTextureSize(const osg::Vec2& textureSize)
{
if(_textureSize != textureSize)
{
_textureSize = textureSize;
dirty();
}
}
void ShadowMap::init()
{
if (!_shadowedScene) return;
unsigned int tex_width = _textureSize.x();
unsigned int tex_height = _textureSize.y();
_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);
// 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()
{
}
/* -*-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.
*/
#ifndef OSGSHADOW_SHADOWEMAP
#define OSGSHADOW_SHADOWEMAP 1
#include <osg/Camera>
#include <osg/Material>
#include <osgShadow/ShadowTechnique>
namespace osgShadow {
/** ShadowedTexture provides an implementation of shadow textures.*/
class OSGSHADOW_EXPORT ShadowMap : public ShadowTechnique
{
public :
ShadowMap();
ShadowMap(const ShadowMap& es, const osg::CopyOp&
copyop=osg::CopyOp::SHALLOW_COPY);
META_Object(osgShadow, ShadowMap);
/** Set the texture unit that the shadow texture will be applied on.*/
void setTextureUnit(unsigned int unit);
/** Get the texture unit that the shadow texture will be applied on.*/
unsigned int getTextureUnit() const { return _textureUnit; }
/** Set the values for the ambient bias the shader will use.*/
void setAmbientBias(const osg::Vec2& ambientBias );
/** Get the values that are used for the ambient bias in the shader.*/
const osg::Vec2& getAmbientBias() const { return _ambientBias; }
/** Set the values for the texture size, default at constructions
1024x1024.*/
void setTextureSize(const osg::Vec2& textureSize );
/** Get the values that are used for the depth texture size.*/
const osg::Vec2& getTextureSize() const { return _textureSize; }
/** initialize the ShadowedScene and local cached data structures.*/
virtual void init();
/** run the update traversal of the ShadowedScene and update any loca
chached data structures.*/
virtual void update(osg::NodeVisitor& nv);
/** run the cull traversal of the ShadowedScene and set up the
rendering for this ShadowTechnique.*/
virtual void cull(osgUtil::CullVisitor& cv);
/** Clean scene graph from any shadow technique specific nodes, state
and drawables.*/
virtual void cleanSceneGraph();
protected :
virtual ~ShadowMap() {}
osg::ref_ptr<osg::Camera> _camera;
osg::ref_ptr<osg::TexGen> _texgen;
osg::ref_ptr<osg::Texture2D> _texture;
osg::ref_ptr<osg::StateSet> _stateset;
unsigned int _textureUnit;
osg::Vec2 _ambientBias;
osg::Vec2 _textureSize;
};
}
#endif
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