关于网格被波动海面穿透

killlu

这几天做的一个网格在海面上漂浮的效果，但发现海面起伏时总是有点穿透网格。代码如下。请教大家。
class DynamicGeomCallBack:public osg:rawable::UpdateCallback
{
public:
DynamicGeomCallBack(osg::ref_ptr<osgOcean::OceanScene> scene):_scene(scene){}
virtual void update(osg::NodeVisitor* nv, osg::Drawable* drawable)
{
  //osg::Matrix mat = osg::computeLocalToWorld(nv->getNodePath());
  osg::Geometry* geome = dynamic_cast<osg::Geometry*>(drawable);
  if (!geome)
   return;
  osg::Vec3Array* vertics = dynamic_cast<osg::Vec3Array*>(geome->getVertexArray());
  if (vertics)
  {
   for (osg::Vec3Array::iterator itr = vertics->begin();itr != vertics->end();++itr)
   {
    float z = _scene->getOceanSurfaceHeightAt((*itr).x(),(*itr).y());
    (*itr).set(osg::Vec3((*itr).x(),(*itr).y(),z+0.5f));
   }
   vertics->dirty();
  }
}
private:
osgOcean::OceanScene* _scene;
};

static osg::ref_ptr<osg::Geode> createWaveGrid(osg::Vec3 boatPos,osg::Vec3 boatToward,osgOcean::OceanScene* scene,float waveWidth = 30.0f,float waveLength = 50.0f)
{
osg:uat qt;
boatToward.normalize();
qt.makeRotate(osg::Vec3(0.0,1.0,0.0),boatToward);
osg::Matrix mt;
mt.makeRotate(qt);
int _numx = (int)(waveWidth/2.0f) ,_numy = (int)(waveLength/2.0f);
osg::ref_ptr<osg::Geode> geode = new osg::Geode;
osg::ref_ptr<osg::Geometry> geome = new osg::Geometry;
osg::Vec3Array* vertices = new osg::Vec3Array(_numx*_numy);
float dx = waveWidth/(float)(_numx-1);
float dy = waveLength/(float)(_numy-1);
unsigned int vert_no = 0;
unsigned int vertx_no = 0;
unsigned int iy;
for(iy=0; iy<_numy; ++iy)
{
  osg::Vec3 column = boatPos;
  for(unsigned int ix=0;ix<_numx;++ix)
  {
   (*vertices)[vert_no++] = column*mt;
   if ((ix == 0) && (iy == 0))
   {
    osg::Vec3 a = column;
    std::cout<<a.x()<<"   "<<a.y()<<"   "<<a.z()<<std::endl;
   }
   column.x() += dx;
   column.z() = 0.5f;
  }
  boatPos.y() += dy;
}
geome->setVertexArray(vertices);
for(iy=0; iy<_numy-1; ++iy)
{
  unsigned int element_no = 0;
  osg::DrawElementsUInt* elements = new osg::DrawElementsUInt(GL_TRIANGLE_STRIP, _numx*2);
  unsigned int index = iy * _numx;
  for(unsigned int ix = 0; ix<_numx; ++ix)
  {
   (*elements)[element_no++] = index + _numx;
   (*elements)[element_no++] = index++;
  }
  geome->addPrimitiveSet(elements);
}
geome->setUpdateCallback(new DynamicGeomCallBack(scene));
geome->setUseDisplayList(false);
geome->setUseVertexBufferObjects(true);
geode->addDrawable(geome);
return geode.get();
}

array

1. float z = _scene->getOceanSurfaceHeightAt

复制代码

这里也许可以适当地把Z提升，以避免Z-Fighting的问题

killlu

回复 2# array


    提升Z值的方法我做过，但是有个问题就是，我从近处观察发现网格与海面的起伏有所不同，经常在某些地方出现海面顶点上升，而网格下降，所以造成了穿透。但是我从代码这边看不出什么原因，还请大家帮我考虑下出现该问题的可能原因。谢谢。

array

从有限的代码里我也看不出什么东西~~

gaodahongosg

关闭网格geometry的深度测试