Hi Ruqin, I'm not going to review your code as it's pointless, it's not seeing the wood from the trees. Answer the question I asked, is it back face culling that you are talking about?? In your OpenGL app did you enable/disable back face culling?
Robert. 2009/3/18 Ruqin Zhang <[email protected]> > Sorry about the confusion. Here is the openGL code that works: > > *triangle t;* > * const float* pFltArrayN = t.getNormal();* > * const float* pFltArray1 = t.getVert1();* > * const float* pFltArray2 = t.getVert2();* > * const float* pFltArray3 = t.getVert3();* > > * glNormal3fv(pFltArrayN);* > * glVertex3fv(pFltArray1);* > * glVertex3fv(pFltArray2);* > * glVertex3fv(pFltArray3);* > * * > * a[0] = -pFltArrayN[0];* > * a[1] = -pFltArrayN[1];* > * a[2] = -pFltArrayN[2];* > * glNormal3fv(a);* > * glVertex3fv(pFltArray3);* > * glVertex3fv(pFltArray2);* > * glVertex3fv(pFltArray1);* > > I tried to do the same thing in osg, here is my code: > > *osg::ref_ptr<osg::Material> material = new osg::Material(); > > material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4f(0.00f,0.00f,0.00f,0.00f)); > osg::ref_ptr<osg::PolygonMode> polymode = new osg::PolygonMode(); > polymode->setMode(osg::PolygonMode::FRONT_AND_BACK,osg::PolygonMode::FILL); > osg::ref_ptr<osg::StateSet> stateset = new osg::StateSet(); > > stateset->setAttributeAndModes(material.get(),osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON); > > stateset->setAttributeAndModes(polymode.get(),osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON); > > stateset->setMode(GL_LIGHTING,osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON); > > stateset->setTextureMode(0,GL_TEXTURE_2D,osg::StateAttribute::OVERRIDE|osg::StateAttribute::OFF); > * > > *for(int j = 0; j < mesh->getNumTriangles(); j ++)* > *{* > * osg::DrawElementsUInt* frontTriElement = new > osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES,0);* > * frontTriElement->push_back(mesh->getTri(j).getVert1Index());* > * frontTriElement->push_back(mesh->getTri(j).getVert2Index());* > * frontTriElement->push_back(mesh->getTri(j).getVert3Index());* > * meshGeometry->addPrimitiveSet(frontTriElement);* > * osg::Vec3f normalVec(mesh->getTri(j).getNormalVec3().x, > mesh->getTri(j).getNormalVec3().y,* > * > mesh->getTri(j).getNormalVec3().z);* > * normalArray->push_back(normalVec);* > > * osg::DrawElementsUInt* backTriElement = new > osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES,0);* > * backTriElement->push_back(mesh->getTri(j).getVert3Index());* > * backTriElement->push_back(mesh->getTri(j).getVert2Index());* > * backTriElement->push_back(mesh->getTri(j).getVert1Index());* > * meshGeometry->addPrimitiveSet(backTriElement);* > * normalArray->push_back(-normalVec);* > *}* > *meshGeometry->setStateSet(stateset.get());* > *meshGeometry->setVertexArray(vertexArray.get());* > *meshGeometry->setNormalArray(normalArray.get());* > *meshGeometry->setNormalBinding(osg::Geometry::BIND_PER_PRIMITIVE);* > > While seems this doesn't work. Any problem or mistake? Thanks a lot! > > Ruqin > > > 2009/3/18 Robert Osfield <[email protected]> > >> Hi Ruqin, >> >> >> 2009/3/18 Ruqin Zhang <[email protected]> >> >>> Thanks Robert. Alright, here is the deal. I'm trying to draw a 3D >>> triangular mesh with osg. For some mesh, the calculated normal points >>> to the inside. So, I want to draw both the front and back faces, which >>> have opposite normals. Then you can render the mesh visible. >>> Is there an example of this? Thanks! >>> >> >> Are you talking about two face lighting of back face culling here?? >> Originally your email sounded like you were talking about lighting at back >> face culling has nothing to do with normals, but this new emails sounds like >> you might be refering to back face culling... >> >> Robert. >> >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> >> > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >
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