Hi,
How to calculate normal vector using the osg::smoothingVisitor ?
Guide me by providing some example related to above question .
I have to find normal for lightning effect. I have draw various model
using triangle strip . Now i'm in need of finding normal.
Here I'have attached some part of simple model of cube .
Kindly help me what is the best way for me to finding normal here
Some part of my code is :
// front face of Cube
{
{
osg::Geometry* pGeo = new osg::Geometry;
// add 4 vertices creating a quad
osg::Vec3Array* pVerts = new osg::Vec3Array(3);
(*pVerts)[0].set((*points1)[0].x() ,(*points1)[0].y() ,
(*points1)[0].z());
(*pVerts)[1].set((*points1)[1].x() ,(*points1)[1].y() ,
(*points1)[1].z());
(*pVerts)[2].set((*points1)[2].x() ,(*points1)[2].y() ,
(*points1)[2].z());
pGeo->setVertexArray( pVerts );
// create a primitive set
osg::DrawElementsUInt* pPrimitiveSet = new
osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES, 0 );
pPrimitiveSet->push_back( 0 );
pPrimitiveSet->push_back( 1 );
pPrimitiveSet->push_back( 2 );
pGeo->addPrimitiveSet( pPrimitiveSet );
// create an arraw for texture coordinates
osg::Vec2Array* pTexCoords = new osg::Vec2Array( 3 );
(*pTexCoords)[0].set( (*points2)[9].x() , (*points2)[9].y() );
(*pTexCoords)[1].set( (*points2)[8].x() , (*points2)[8].y() );
(*pTexCoords)[2].set( (*points2)[7].x() , (*points2)[7].y() );
pGeo->setTexCoordArray( 0, pTexCoords );
// create geometry node that will contain all our drawables
geode->addDrawable( pGeo );
}
{
osg::Geometry* pGeo = new osg::Geometry;
// add 4 vertices creating a quad
osg::Vec3Array* pVerts = new osg::Vec3Array(3);
(*pVerts)[0].set((*points1)[0].x() ,(*points1)[0].y() ,
(*points1)[0].z());
(*pVerts)[1].set((*points1)[2].x() ,(*points1)[2].y() ,
(*points1)[2].z());
(*pVerts)[2].set((*points1)[3].x() ,(*points1)[3].y() ,
(*points1)[3].z());
pGeo->setVertexArray( pVerts );
// create a primitive set
osg::DrawElementsUInt* pPrimitiveSet = new
osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES, 0 );
pPrimitiveSet->push_back( 0 );
pPrimitiveSet->push_back( 1 );
pPrimitiveSet->push_back( 2 );
pGeo->addPrimitiveSet( pPrimitiveSet );
// create an arraw for texture coordinates
osg::Vec2Array* pTexCoords = new osg::Vec2Array( 3 );
(*pTexCoords)[0].set( (*points2)[9].x() , (*points2)[9].y() );
(*pTexCoords)[1].set( (*points2)[7].x() , (*points2)[7].y() );
(*pTexCoords)[2].set( (*points2)[10].x() , (*points2)[10].y() );
pGeo->setTexCoordArray( 0, pTexCoords );
// create geometry node that will contain all our drawables
geode->addDrawable( pGeo );
}
}
//Side right face
{
{
osg::Geometry* pGeo = new osg::Geometry;
// add 4 vertices creating a quad
osg::Vec3Array* pVerts = new osg::Vec3Array(3);
(*pVerts)[0].set((*points1)[1].x() ,(*points1)[1].y() ,
(*points1)[1].z());
(*pVerts)[1].set((*points1)[5].x() ,(*points1)[5].y() ,
(*points1)[5].z());
(*pVerts)[2].set((*points1)[6].x() ,(*points1)[6].y() ,
(*points1)[6].z());
pGeo->setVertexArray( pVerts );
// create a primitive set
osg::DrawElementsUInt* pPrimitiveSet = new
osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES, 0 );
pPrimitiveSet->push_back( 0 );
pPrimitiveSet->push_back( 1 );
pPrimitiveSet->push_back( 2 );
pGeo->addPrimitiveSet( pPrimitiveSet );
// create an arraw for texture coordinates
osg::Vec2Array* pTexCoords = new osg::Vec2Array( 3 );
(*pTexCoords)[0].set( (*points2)[6].x() , (*points2)[6].y() );
(*pTexCoords)[1].set( (*points2)[5].x() , (*points2)[5].y() );
(*pTexCoords)[2].set( (*points2)[4].x() , (*points2)[4].y() );
pGeo->setTexCoordArray( 0, pTexCoords );
// create geometry node that will contain all our drawables
geode->addDrawable( pGeo );
}
{
osg::Geometry* pGeo = new osg::Geometry;
// add 4 vertices creating a quad
osg::Vec3Array* pVerts = new osg::Vec3Array(3);
(*pVerts)[0].set((*points1)[1].x() ,(*points1)[1].y() ,
(*points1)[1].z());
(*pVerts)[1].set((*points1)[6].x() ,(*points1)[6].y() ,
(*points1)[6].z());
(*pVerts)[2].set((*points1)[2].x() ,(*points1)[2].y() ,
(*points1)[2].z());
pGeo->setVertexArray( pVerts );
// create a primitive set
osg::DrawElementsUInt* pPrimitiveSet = new
osg::DrawElementsUInt( osg::PrimitiveSet::TRIANGLES, 0 );
pPrimitiveSet->push_back( 0 );
pPrimitiveSet->push_back( 1 );
pPrimitiveSet->push_back( 2 );
pGeo->addPrimitiveSet( pPrimitiveSet );
// create an arraw for texture coordinates
osg::Vec2Array* pTexCoords = new osg::Vec2Array( 3 );
(*pTexCoords)[0].set( (*points2)[6].x() , (*points2)[6].y() );
(*pTexCoords)[1].set( (*points2)[4].x() , (*points2)[4].y() );
(*pTexCoords)[2].set( (*points2)[7].x() , (*points2)[7].y() );
pGeo->setTexCoordArray( 0, pTexCoords );
// create geometry node that will contain all our drawables
geode->addDrawable( pGeo );
}
}
...
Thank you!
Cheers,
manish
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=33603#33603
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