FGFS-4.1/OpenSceneGraph
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Improved GLSL isosurface support when using a transfer function

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This commit is contained in:
Robert Osfield 2008-09-26 15:47:31 +00:00
parent 21865d3ec1
commit d8cfc9b1f5
2 changed files with 23 additions and 6 deletions
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8
examples/osgvolume/osgvolume.cpp
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@ -876,6 +876,9 @@ osg::Node* createShaderModel(ShadingModel shadingModel,
texture3D->setImage(image_3d.get());
stateset->setTextureAttributeAndModes(0,texture3D,osg::StateAttribute::ON);
osg::Uniform* baseTextureSampler = new osg::Uniform("baseTexture",0);
stateset->addUniform(baseTextureSampler);
}
@ -943,7 +946,7 @@ osg::Node* createShaderModel(ShadingModel shadingModel,
texture1D->setWrap(osg::Texture::WRAP_R,osg::Texture::CLAMP_TO_EDGE);
stateset->setTextureAttributeAndModes(0,texture1D,osg::StateAttribute::ON);
osg::Shader* fragmentShader = osgDB::readShaderFile(osg::Shader::FRAGMENT, "volume-tf-iso.frag");
osg::Shader* fragmentShader = osgDB::readShaderFile(osg::Shader::FRAGMENT, "volume_tf_iso.frag");
if (fragmentShader)
{
program->addShader(fragmentShader);
@ -1056,6 +1059,7 @@ osg::Node* createShaderModel(ShadingModel shadingModel,
}
else
{
osg::Shader* fragmentShader = osgDB::readShaderFile(osg::Shader::FRAGMENT, "volume.frag");
if (fragmentShader)
{
@ -1067,8 +1071,6 @@ osg::Node* createShaderModel(ShadingModel shadingModel,
program->addShader(new osg::Shader(osg::Shader::FRAGMENT, volume_frag));
}
}
osg::Uniform* baseTextureSampler = new osg::Uniform("baseTexture",0);
stateset->addUniform(baseTextureSampler);
osg::Uniform* sampleDensity = new osg::Uniform("sampleDensity", 0.01f);
stateset->addUniform(sampleDensity);

21
examples/osgvolume/volume_tf_iso_frag.cpp
View File

@ -1,4 +1,4 @@
char volume_tf_iso_frag[] = "uniform sampler3D baseTexture;\n"
char volume_tf_iso_frag[] = "uniform sampler3D normalMap;\n"
"uniform sampler1D tfTexture;\n"
"uniform float sampleDensity;\n"
"uniform float transparency;\n"
@ -13,6 +13,8 @@ char volume_tf_iso_frag[] = "uniform sampler3D baseTexture;\n"
" vec3 t0 = (texgen * vertexPos).xyz;\n"
" vec3 te = (texgen * cameraPos).xyz;\n"
"\n"
" vec3 eyeDirection = normalize(te-t0);\n"
"\n"
" if (te.x>=0.0 && te.x<=1.0 &&\n"
" te.y>=0.0 && te.y<=1.0 &&\n"
" te.z>=0.0 && te.z<=1.0)\n"
@ -73,12 +75,25 @@ char volume_tf_iso_frag[] = "uniform sampler3D baseTexture;\n"
" vec4 fragColor = vec4(0.0, 0.0, 0.0, 0.0); \n"
" while(num_iterations>0.0)\n"
" {\n"
" float v = texture3D( baseTexture, texcoord).s;\n"
" vec4 normal = texture3D( normalMap, texcoord);\n"
" float v = normal.w;\n"
" vec4 color = texture1D( tfTexture, v);\n"
" if (alphaCutOff<color.w)\n"
"\n"
" normal.x = normal.x*2.0-1.0;\n"
" normal.y = normal.y*2.0-1.0;\n"
" normal.z = normal.z*2.0-1.0;\n"
" \n"
" float lightScale = 0.1 + max(dot(normal.xyz, eyeDirection), 0.0);\n"
" color.x *= lightScale;\n"
" color.y *= lightScale;\n"
" color.z *= lightScale;\n"
" color.w = 1.0;\n"
" \n"
" if (v>=alphaCutOff)\n"
" {\n"
" fragColor = color;\n"
" }\n"
"\n"
" texcoord += deltaTexCoord; \n"
"\n"
" --num_iterations;\n"