Hi Jean,
I modified the code in the functions and it seemed fairly straightforward.
However, I notice that all the cylinders are rendered at the origin inspite of
me doing a glTranslate (which I have commented out now).
When I opened the osg file I noticed that the matrix had its last column as
0,0,0,1 -> which means that the cylinder did not translate prior to rendering.
I tried a number of different things like placing a matrix transform above each
Geode while creating the scene graph. But even that didn't quite give any
positive results.
I have mentioned my cylinder geometry creation code below which returns a Geode.
Thanks,
Sanat.
Code:
osg::ref_ptr<osg::Geode> createCylinderGeode(osg::ref_ptr<osg::Cylinder>
cylinder)
//osg::ref_ptr<osg::Geode> createCylinderGeode(unsigned int numSegments, float
RADIUS, float height,
// osg::Vec3 center)
{
unsigned int numSegments = 90;
const float angleDelta = 2.0f*osg::PI/(float)numSegments;
const float texCoordDelta = 1.0f/(float)numSegments;
//const float r = RADIUS;
//const float h = height;
const float r = cylinder->getRadius();
const float h = cylinder->getHeight();
float basez = -h*0.5f;
float topz = h*0.5f;
float angle = 0.0f;
float texCoord = 0.0f;
bool drawFrontFace = true;
bool drawBackFace = false;
// The only difference between the font & back face loops is that the
// normals are inverted and the order of the vertex pairs is reversed.
// The code is mostly duplicated in order to hoist the back/front face
// test out of the loop for efficiency
osg::ref_ptr<osg::Geode> cylinderGeode = new osg::Geode();
osg::ref_ptr<osg::Geometry> cylinderBody = new osg::Geometry();
osg::ref_ptr<osg::Geometry> cylinderTop = new osg::Geometry();
osg::ref_ptr<osg::Geometry> cylinderBottom = new osg::Geometry();
osg::ref_ptr<osg::Vec3Array> bodyVertexArray = new osg::Vec3Array();
osg::ref_ptr<osg::Vec3Array> bodyNormalArray = new osg::Vec3Array();
osg::ref_ptr<osg::Vec3Array> topVertexArray = new osg::Vec3Array();
osg::ref_ptr<osg::Vec3Array> topNormalArray = new osg::Vec3Array();
osg::ref_ptr<osg::Vec3Array> bottomVertexArray = new osg::Vec3Array();
osg::ref_ptr<osg::Vec3Array> bottomNormalArray = new osg::Vec3Array();
//Draw BODY
glBegin(GL_TRIANGLE_STRIP);
if (drawFrontFace)
{
for(unsigned int bodyi=0;
bodyi<numSegments;
++bodyi,angle+=angleDelta,texCoord+=texCoordDelta)
{
float c = cosf(angle);
float s = sinf(angle);
bodyNormalArray->push_back(osg::Vec3(c,s,0.0f));
//glTexCoord2f(texCoord,1.0f);
bodyVertexArray->push_back(osg::Vec3(c*r,s*r,topz));
//glTexCoord2f(texCoord,0.0f);
bodyVertexArray->push_back(osg::Vec3(c*r,s*r,basez));
}
// do last point by hand to ensure no round off errors.
bodyNormalArray->push_back(osg::Vec3(1.0f,0.0f,0.0f));
//glTexCoord2f(1.0f,1.0f);
bodyVertexArray->push_back(osg::Vec3(r,0.0f,topz));
//glTexCoord2f(1.0f,0.0f);
bodyVertexArray->push_back(osg::Vec3(r,0.0f,basez));
}//if (drawFrontFace)
glEnd(); //glBegin(GL_TRIANGLE_STRIP);
//create TOP
glBegin(GL_TRIANGLE_FAN);
topNormalArray->push_back(osg::Vec3(0.0f,0.0f,1.0f));
//glTexCoord2f(0.5f,0.5f);
topVertexArray->push_back(osg::Vec3(0.0f,0.0f,topz));
angle = 0.0f;
texCoord = 0.0f;
for(unsigned int topi=0;
topi<numSegments;
++topi,angle+=angleDelta,texCoord+=texCoordDelta)
{
float c = cosf(angle);
float s = sinf(angle);
//glTexCoord2f(c*0.5f+0.5f,s*0.5f+0.5f);
topVertexArray->push_back(osg::Vec3(c*r,s*r,topz));
}
//glTexCoord2f(1.0f,0.5f);
topVertexArray->push_back(osg::Vec3(r,0.0f,topz));
glEnd();
//create BOTTOM
//glTranslatef(cylunder.center.x(), cylinder.center.y(), cylinder.center.z());
glBegin(GL_TRIANGLE_FAN);
bottomNormalArray->push_back(osg::Vec3(0.0f,0.0f,-1.0f));
//glTexCoord2f(0.5f,0.5f);
bottomVertexArray->push_back(osg::Vec3(0.0f,0.0f,basez));
angle = osg::PI*2.0f;
//texCoord = 1.0f;
for(unsigned int bottomi=0;
bottomi<numSegments;
++bottomi, angle -= angleDelta, texCoord -= texCoordDelta)
{
float c = cosf(angle);
float s = sinf(angle);
//glTexCoord2f(c*0.5f+0.5f,s*0.5f+0.5f);
bottomVertexArray->push_back(osg::Vec3(c*r,s*r,basez));
}
//glTexCoord2f(1.0f,0.5f);
bottomVertexArray->push_back(osg::Vec3(r,0.0f,basez));
glEnd();
glPopMatrix();
//add vertex array to geometry
cylinderBody->setVertexArray(bodyVertexArray.get());
cylinderBody->setNormalArray(bodyNormalArray.get());
cylinderTop->setVertexArray(topVertexArray.get());
cylinderTop->setNormalArray(topNormalArray.get());
cylinderBottom->setVertexArray(bottomVertexArray.get());
cylinderBottom->setNormalArray(bottomNormalArray.get());
//add primitives to geometry
cylinderBody->addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_STRIP, 0 ,
bodyVertexArray->size()));
cylinderTop->addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_FAN, 0, topVertexArray->size()));
cylinderBottom->addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::TRIANGLE_FAN, 0, bottomVertexArray->size()));
//add geometry to geode
//cylinderGeode->addDrawable(cylinderTop.get());
//cylinderGeode->addDrawable(cylinderBottom.get());
cylinderGeode->addDrawable(cylinderBody.get());
return cylinderGeode.get();
}
Thanks
Sanat
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=37164#37164
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