Hi, I have a minor addition I would like to see in svn for the SoftShadowMap implementation:
SoftShadowMap::setBias/getBias()
To add a small bias to the depth test. It can sometimes reduce some
artifacts of shadowmap (adding others though).
set/getTextureSize() to change the resolution of the render target texture.
Modified files are attached.
Cheers,
Anders
--
________________________________________________________________
Anders Backman Email: [EMAIL PROTECTED]
HPC2N/VRlab Phone: +46 (0)90-786 9936
Umea university Cellular: +46 (0)70-392 64 67
S-901 87 UMEA SWEDEN Fax: +46 90-786 6126
http://www.cs.umu.se/~andersb
/* -*-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 <stdlib.h>
#include <osgShadow/SoftShadowMap>
#include <osgShadow/ShadowedScene>
#include <osg/Notify>
#include <osg/ComputeBoundsVisitor>
#include <osg/PolygonOffset>
#include <osg/CullFace>
#include <osg/io_utils>
#include <osg/Texture3D>
#include <osg/TexGen>
#include <iostream>
using namespace osgShadow;
//////////////////////////////////////////////////////////////////
// fragment shader
//
// Implementation from Chapter 17, Efficient Soft-Edged Shadows Using Pixel
Shader Branching, Yury Uralsky.
// GPU Gems 2, Matt Pharr ed. Addison-Wesley.
//
static const char fShaderSource_noBaseTexture[] =
"#define SAMPLECOUNT 64 \n"
"#define SAMPLECOUNT_FLOAT 64.0 \n"
"#define SAMPLECOUNT_D2 32 \n"
"#define SAMPLECOUNT_D2_FLOAT 32.0 \n"
"#define INV_SAMPLECOUNT (1.0 / SAMPLECOUNT_FLOAT) \n"
"uniform sampler2DShadow shadowTexture; \n"
"uniform sampler3D jitterMapSampler; \n"
"uniform vec2 ambientBias; \n"
"uniform float softwidth; \n"
"uniform float jscale; \n"
"void main(void) \n"
"{ \n"
" vec4 sceneShadowProj = gl_TexCoord[1]; \n"
" float softFactor = softwidth * sceneShadowProj.w; \n"
" vec4 smCoord = sceneShadowProj; \n"
" vec3 jitterCoord = vec3( gl_FragCoord.xy / jscale, 0.0 ); \n"
" vec4 shadow = vec4(0.0, 0.0, 0.0, 0.0); \n"
// First "cheap" sample test
" const float pass_div = 1.0 / (2.0 * 4.0); \n"
" for ( int i = 0; i < 4; ++i ) \n"
" { \n"
// Get jitter values in [0,1]; adjust to have values in [-1,1]
" vec4 offset = 2.0 * texture3D( jitterMapSampler, jitterCoord ) -1.0;
\n"
" jitterCoord.z += 1.0 / SAMPLECOUNT_D2_FLOAT; \n"
" smCoord.xy = sceneShadowProj.xy + (offset.xy) * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * pass_div; \n"
" smCoord.xy = sceneShadowProj.xy + (offset.zw) * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) *pass_div; \n"
" } \n"
// skip all the expensive shadow sampling if not needed
" if ( shadow * (shadow -1.0) != 0.0 ) \n"
" { \n"
" shadow *= pass_div; \n"
" for (int i=0; i<SAMPLECOUNT_D2 - 4; ++i){ \n"
" vec4 offset = 2.0 * texture3D( jitterMapSampler, jitterCoord ) -
1.0; \n"
" jitterCoord.z += 1.0 / SAMPLECOUNT_D2_FLOAT; \n"
" smCoord.xy = sceneShadowProj.xy + offset.xy * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * INV_SAMPLECOUNT;
\n"
" smCoord.xy = sceneShadowProj.xy + offset.zw * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * INV_SAMPLECOUNT;
\n"
" } \n"
" } \n"
// apply shadow, modulo the ambient bias
" gl_FragColor = gl_Color * (ambientBias.x + shadow * ambientBias.y); \n"
"} \n";
//////////////////////////////////////////////////////////////////
// fragment shader
//
static const char fShaderSource_withBaseTexture[] =
"#define SAMPLECOUNT 64 \n"
"#define SAMPLECOUNT_FLOAT 64.0 \n"
"#define SAMPLECOUNT_D2 32 \n"
"#define SAMPLECOUNT_D2_FLOAT 32.0 \n"
"#define INV_SAMPLECOUNT (1.0 / SAMPLECOUNT_FLOAT) \n"
"uniform sampler2D baseTexture; \n"
"uniform sampler2DShadow shadowTexture; \n"
"uniform sampler3D jitterMapSampler; \n"
"uniform vec2 ambientBias; \n"
"uniform float softwidth; \n"
"uniform float jscale; \n"
"void main(void) \n"
"{ \n"
" vec4 sceneShadowProj = gl_TexCoord[1]; \n"
" float softFactor = softwidth * sceneShadowProj.w; \n"
" vec4 smCoord = sceneShadowProj; \n"
" vec3 jitterCoord = vec3( gl_FragCoord.xy / jscale, 0.0 ); \n"
" vec4 shadow = vec4(0.0, 0.0, 0.0, 0.0); \n"
// First "cheap" sample test
" const float pass_div = 1.0 / (2.0 * 4.0); \n"
" for ( int i = 0; i < 4; ++i ) \n"
" { \n"
// Get jitter values in [0,1]; adjust to have values in [-1,1]
" vec4 offset = 2.0 * texture3D( jitterMapSampler, jitterCoord ) -1.0;
\n"
" jitterCoord.z += 1.0 / SAMPLECOUNT_D2_FLOAT; \n"
" smCoord.xy = sceneShadowProj.xy + (offset.xy) * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * pass_div; \n"
" smCoord.xy = sceneShadowProj.xy + (offset.zw) * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) *pass_div; \n"
" } \n"
// skip all the expensive shadow sampling if not needed
" if ( shadow * (shadow -1.0) != 0.0 ) \n"
" { \n"
" shadow *= pass_div; \n"
" for (int i=0; i<SAMPLECOUNT_D2 -4; ++i){ \n"
" vec4 offset = 2.0 * texture3D( jitterMapSampler, jitterCoord ) -
1.0; \n"
" jitterCoord.z += 1.0 / SAMPLECOUNT_D2_FLOAT; \n"
" smCoord.xy = sceneShadowProj.xy + offset.xy * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * INV_SAMPLECOUNT;
\n"
" smCoord.xy = sceneShadowProj.xy + offset.zw * softFactor; \n"
" shadow += shadow2DProj( shadowTexture, smCoord ) * INV_SAMPLECOUNT;
\n"
" } \n"
" } \n"
// apply color and object base texture
" vec4 color = gl_Color * texture2D( baseTexture, gl_TexCoord[0].xy ); \n"
// apply shadow, modulo the ambient bias
" gl_FragColor = color * (ambientBias.x + shadow * ambientBias.y); \n"
"} \n";
SoftShadowMap::SoftShadowMap():
_textureUnit(1),
_ambientBias(0.5f,0.5f),
_softnesswidth(0.005f),
_jitteringscale(32.f),
_bias(0.0f),
_textureSize(1024, 1024)
{
}
SoftShadowMap::SoftShadowMap(const SoftShadowMap& copy, const osg::CopyOp&
copyop):
ShadowTechnique(copy,copyop),
_textureUnit(copy._textureUnit),
_ambientBias(copy._ambientBias),
_softnesswidth(copy._softnesswidth),
_jitteringscale(copy._jitteringscale),
_bias(copy._bias),
_textureSize(copy._textureSize)
{
}
void SoftShadowMap::setTextureUnit(unsigned int unit)
{
_textureUnit = unit;
}
void SoftShadowMap::setAmbientBias(const osg::Vec2& ambientBias)
{
_ambientBias = ambientBias;
}
void SoftShadowMap::setSoftnessWidth(const float softnesswidth )
{
_softnesswidth = softnesswidth;
}
void SoftShadowMap::setJitteringScale(const float jitteringscale )
{
_jitteringscale = jitteringscale;
}
void SoftShadowMap::setTextureSize(int tex_width, int tex_height)
{
_textureSize.set(tex_width, tex_height);
if (_texture.valid()) {
_texture->setTextureSize(tex_width, tex_height);
_camera->setViewport(0,0,tex_width,tex_height);
}
}
void SoftShadowMap::init()
{
if (!_shadowedScene) return;
_texture = new osg::Texture2D;
_texture->setTextureSize(_textureSize[0], _textureSize[1]);
_texture->setInternalFormat(GL_DEPTH_COMPONENT);
_texture->setSourceType(GL_UNSIGNED_INT);
// Sets GL_TEXTURE_COMPARE_MODE_ARB to GL_COMPARE_R_TO_TEXTURE_ARB
_texture->setShadowComparison(true);
_texture->setShadowCompareFunc(osg::Texture::LEQUAL);
_texture->setShadowTextureMode(osg::Texture::LUMINANCE);
_texture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::LINEAR);
_texture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::LINEAR);
_texture->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
_texture->setWrap(osg::Texture::WRAP_T, osg::Texture::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,_textureSize[0],_textureSize[1]);
// 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;
// set culling to BACK facing (cf message from Wojtek Lewandowski in
osg Mailing list)
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;
osg::Program* program = new osg::Program;
_stateset->setAttribute(program);
if ( _textureUnit==0)
{
osg::Shader* fragment_shader = new
osg::Shader(osg::Shader::FRAGMENT, fShaderSource_noBaseTexture);
program->addShader(fragment_shader);
}
else
{
osg::Shader* fragment_shader = new
osg::Shader(osg::Shader::FRAGMENT, fShaderSource_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);
// bhbn
// Initialisation of jittering texture
initJittering(_stateset.get());
osg::Uniform* jitterMapSampler = new
osg::Uniform("jitterMapSampler",(int)_textureUnit + 1);
_stateset->addUniform(jitterMapSampler);
osg::Uniform* softwidth = new osg::Uniform("softwidth",_softnesswidth);
_stateset->addUniform(softwidth);
osg::Uniform* jscale = new osg::Uniform("jscale",_jitteringscale);
_stateset->addUniform(jscale);
}
_dirty = false;
}
void SoftShadowMap::update(osg::NodeVisitor& nv)
{
_shadowedScene->osg::Group::traverse(nv);
}
void SoftShadowMap::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();
osg::Vec3 position;
if (lightpos[3]!=0.0)
{
position.set(lightpos.x(), lightpos.y(), lightpos.z());
}
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
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(0.5,0.5,0.5+_bias);
_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 SoftShadowMap::cleanSceneGraph()
{
}
// Implementation from Chapter 17, Efficient Soft-Edged Shadows Using Pixel
Shader Branching, Yury Uralsky.
// GPU Gems 2, Matt Pharr ed. Addison-Wesley.
//
// Creates a 3D texture containing jittering data used in the shader to take
samples of the shadow map.
void SoftShadowMap::initJittering(osg::StateSet *ss)
{
// create a 3D texture with hw mipmapping
osg::Texture3D* texture3D = new osg::Texture3D;
texture3D->setFilter(osg::Texture3D::MIN_FILTER,osg::Texture3D::NEAREST);
texture3D->setFilter(osg::Texture3D::MAG_FILTER,osg::Texture3D::NEAREST);
texture3D->setWrap(osg::Texture3D::WRAP_S,osg::Texture3D::REPEAT);
texture3D->setWrap(osg::Texture3D::WRAP_T,osg::Texture3D::REPEAT);
texture3D->setWrap(osg::Texture3D::WRAP_R,osg::Texture3D::REPEAT);
texture3D->setUseHardwareMipMapGeneration(true);
const unsigned int size = 16;
const unsigned int gridW = 8;
const unsigned int gridH = 8;
unsigned int R = (gridW * gridH / 2);
texture3D->setTextureSize(size, size, R);
// then create the 3d image to fill with jittering data
osg::Image* image3D = new osg::Image;
unsigned char *data3D = new unsigned char[size * size * R * 4];
for ( unsigned int s = 0; s < size; ++s )
{
for ( unsigned int t = 0; t < size; ++t )
{
float v[4], d[4];
for ( unsigned int r = 0; r < R; ++r )
{
const int x = r % ( gridW / 2 );
const int y = ( gridH - 1 ) - ( r / (gridW / 2) );
// Generate points on a regular gridW x gridH rectangular
// grid. We multiply x by 2 because, we treat 2
// consecutive x each loop iteration. Add 0.5f to be in
// the center of the pixel. x, y belongs to [ 0.0, 1.0 ].
v[0] = float( x * 2 + 0.5f ) / gridW;
v[1] = float( y + 0.5f ) / gridH;
v[2] = float( x * 2 + 1 + 0.5f ) / gridW;
v[3] = v[1];
// Jitter positions. ( 0.5f / w ) == ( 1.0f / 2*w )
v[0] += ((float)rand() * 2.f / RAND_MAX - 1.f) * ( 0.5f / gridW );
v[1] += ((float)rand() * 2.f / RAND_MAX - 1.f) * ( 0.5f / gridH );
v[2] += ((float)rand() * 2.f / RAND_MAX - 1.f) * ( 0.5f / gridW );
v[3] += ((float)rand() * 2.f / RAND_MAX - 1.f) * ( 0.5f / gridH );
// Warp to disk; values in [-1,1]
d[0] = sqrtf( v[1] ) * cosf( 2.f * 3.1415926f * v[0] );
d[1] = sqrtf( v[1] ) * sinf( 2.f * 3.1415926f * v[0] );
d[2] = sqrtf( v[3] ) * cosf( 2.f * 3.1415926f * v[2] );
d[3] = sqrtf( v[3] ) * sinf( 2.f * 3.1415926f * v[2] );
// store d into unsigned values [0,255]
const unsigned int tmp = ( (r * size * size) + (t * size) + s ) * 4;
data3D[ tmp + 0 ] = (unsigned char)( ( 1.f + d[0] ) * 127 );
data3D[ tmp + 1 ] = (unsigned char)( ( 1.f + d[1] ) * 127 );
data3D[ tmp + 2 ] = (unsigned char)( ( 1.f + d[2] ) * 127 );
data3D[ tmp + 3 ] = (unsigned char)( ( 1.f + d[3] ) * 127 );
}
}
}
// the GPU Gem implementation uses a NV specific internal texture format
(GL_SIGNED_RGBA_NV)
// In order to make it more generic, we use GL_RGBA4 which should be cross
platform.
image3D->setImage(size, size, R, GL_RGBA4, GL_RGBA, GL_UNSIGNED_BYTE,
data3D, osg::Image::USE_NEW_DELETE);
texture3D->setImage(image3D);
ss->setTextureAttributeAndModes((int)_textureUnit + 1, texture3D,
osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
ss->setTextureMode((int)_textureUnit +
1,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
ss->setTextureMode((int)_textureUnit +
1,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
ss->setTextureMode((int)_textureUnit +
1,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
}
softshadowmap
Description: Binary data
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