C++ 计算zBuffer接受错误的值
计算zBuffer接受错误的值 我试图计算我的zBuffer,但我接受了错误的值。我正在加载的模型必须具有不同的Zbuffer值,但我不接受它们。我的值定义为ZFear 1.0f ZFAR 1500.0f我的代码为:C++ 计算zBuffer接受错误的值,c++,opengl,3d,zbuffer,C++,Opengl,3d,Zbuffer,计算zBuffer接受错误的值 我试图计算我的zBuffer,但我接受了错误的值。我正在加载的模型必须具有不同的Zbuffer值,但我不接受它们。我的值定义为ZFear 1.0f ZFAR 1500.0f我的代码为: //calculate the zBuffer GLfloat get_gl_depth() { Pipeline p; int w = glutGet( GLUT_WINDOW_WIDTH ); int h = glutGet( GLUT_WINDOW_H
//calculate the zBuffer
GLfloat get_gl_depth()
{
Pipeline p;
int w = glutGet( GLUT_WINDOW_WIDTH );
int h = glutGet( GLUT_WINDOW_HEIGHT );
glBindBuffer( GL_PIXEL_PACK_BUFFER, pbo );
glBufferData( GL_PIXEL_PACK_BUFFER, w * h * sizeof( GLfloat ), 0, GL_STREAM_READ );
glReadPixels( 0, 0, w, h, GL_DEPTH_COMPONENT, GL_FLOAT, 0 );
GLfloat* ptr = (GLfloat*)glMapBuffer( GL_PIXEL_PACK_BUFFER, GL_READ_ONLY );
unsigned short* buffer=new unsigned short[w*h];
unsigned short* current = buffer;
if (ptr != nullptr)
{
for (int i=0;i<w*h;i++)
{
GLfloat distance =ZNEAR+(GLfloat(ptr[i])*(ZFAR-ZNEAR));
*current++ = unsigned short(distance + 0.5);
}
}
glUnmapBuffer( GL_PIXEL_PACK_BUFFER );
glBindBuffer( GL_PIXEL_PACK_BUFFER, 0 );
delete[] buffer;
return 0;
}
矢量3F位置(0.0f,0.0f,-700.0f)
可能不相关,但在使用透视投影时,深度缓冲区中的深度值是非线性的,因此根据您对距离计算的期望,您可能会失望:)您能给我们展示一下您获得的值的示例吗?还需要指出的是,当您的顶点转换为NDC时,它不再使用右手坐标系,但z实际上是翻转的。我只接受数组ptr值中的1.0000000浮点值,没有任何更改,当我希望接受不同的值,因为我的模型中有一些包含不同高度的建筑时,你说的“转换为NDC”是什么意思?Thanks@user3436304NDC(标准化设备坐标),投影后缩放为[-1,1],z翻转。
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable( GL_DEPTH_TEST );
glDepthMask(GL_TRUE);
const float lightZ = (sinf(m_scale) + 1.0f) / 2.0f;
PointLight pl[10];
int numLights = 0;
pl[numLights++] = CreateLight(0, 0, 0, 255.0f, 0.0f, 0.0f);
pl[numLights++] = CreateLight(0, 0, 100, 0.0f, 255.0f, 0.0f);
pl[numLights++] = CreateLight(100, 0, 100, 0.0f, 0.0f, 255.0f);
m_pEffect->SetPointLights(numLights, pl);
m_pEffect->SetPointLights(3, pl);
Pipeline p;
Vector3f cameraUp = CameraUpVector();
p.SetCamera(m_cameraPosition, m_cameraTarget, cameraUp);
p.SetPerspectiveProj(60.0f, WINDOW_WIDTH, WINDOW_HEIGHT, ZNEAR, ZFAR);
m_pEffect->SetWVP(p.GetWVPTrans());
m_pEffect->SetWorldMatrix(p.GetWorldTrans());
m_pEffect->SetDirectionalLight(m_directionalLight);
m_pEffect->SetEyeWorldPos(m_cameraPosition);
m_pEffect->SetMatSpecularIntensity(0.0f);
m_pEffect->SetMatSpecularPower(0);
m_pMesh->Render();
get_gl_depth(/*WINDOW_WIDTH, WINDOW_HEIGHT*/);
glutSwapBuffers();
This is the func that initlize the first values:
Vector3f Target(0.0f, 0.0f, 0.00001f);
Vector3f Up(0.0, 1.0f, 0.0f);
m_cameraPosition = Pos;
m_cameraTarget = Target;