OPENGL获得点的深度信息

2010-11-03 10:45:42 258 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

openGL之API学习（三十七）如何从FBO中读取颜色、深度信息方法一、保存成图片 QImage* img=new QImage(WINDOW_WIDTH,WINDOW_HEIGHT,QImage::Format_ARGB32); uchar* tmpBIT = img->bits(); //从颜色缓冲区中读取数据 int tmpPixelSize = WINDOW_WIDTH*WINDOW_HEIGHT * 4; ... 阅读详情

glPushMatrix();

glGetIntegerv(GL_VIEWPORT, iViewPort); //获得视口
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(m_fCameraX, m_fCameraY, m_fCameraZ, m_fFocusX, m_fFocusY, m_fFocusZ, m_fUpX, m_fUpY, m_fUpZ); //设置摄像机坐标及方向
glGetDoublev(GL_MODELVIEW_MATRIX,dModelMatrix );

glGetDoublev(GL_PROJECTION_MATRIX,dProjMatrix);
glGetDoublev(GL_DEPTH_RANGE,depth);

GLdouble viewX,viewY,viewZ;
pointx=point.x;
pointy=point.y;
winX = (float)pointx;
winY = (float)iViewPort[3] - (float)pointy;

GLdouble ceshx,ceshy,ceshz,cesht;
GLdouble x,y,z;
GLdouble fdepth;
gluProject(0.5,0.5,0.01,dModelMatrix,dProjMatrix,iViewPort,&x,&y,&z);
glReadPixels(winX,winY,2,2,GL_DEPTH_COMPONENT,GL_FLOAT,&fdepth);
gluUnProject(winX,winY,fdepth,dModelMatrix,dProjMatrix,iViewPort,&ceshx,&ceshy,&ceshz);
为什么我用gluUnProject得到的世界坐标点不正确呢，我用（0.5,0.5 0.01）测试了gluProject函数是正确的，而且glReadPixels读取的深度值总是0.0078，请高手请教这是什么原因呢？

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