从线性深度重建世界位置

时间:2015-01-21 12:09:20

标签: opengl matrix glsl depth-buffer ndc

我有问题从先前存储的glsl线性深度重建世界位置。我在网上看了很多信息,但找不到我的问题...... 所以这就是我得到的:

VS (storing depth to 32F):
float linDepth(float z) {
    return (-z-zNear)/(zFar-zNear);
}
void main() {
    vec4 position = uViewMatrix * uModelMatrix * vec4(aPosition, 1);
    depth = linDepth(position.z); //store linear view-depth
}

FS (reconstuction):
void main() {
    vec3 vUV = vec2(0..1, 0..1); (from screen aligned quad)
    vec3 ndc = vec3(vUV*2-1, linearViewDepth*2-1);
    vec4 v0 = inverse(uProjectionMatrix)*vec4(ndc, 1);
    vec3 reconViewPos = v0.xyz/v0.w;
    vec3 reconWorldPos = inverse(uViewMatrix) * v0;
}

......结果完全没了。 虽然我通过使用未改变的线性视图深度作为ndc z来感知问题。最后,我希望应用光线插值方法:

VS (reconstruction, aligned screenquad):
out vec3 vViewRay;
void main() {
    gl_Position = aPosition;
    vec4 v = vec4(aPosition.x, aPosition.y, 1, 1); //ndc (at the back of cube)
    v = inverse(uProjectionMatrix) * v;
    v /= v.w; //view coordinate
    v /= v.z; //normalize by z for scaling
    vViewRay = v.xyz;
}

FS(reconstruction):
in vec3 vViewRay;
float delinDepth(float z) {
    return -(z*(zFar-zNear)+zNear);
}
void main() {
    vec3 reconViewPos = vViewRay * delinDepth(linearViewDepth);
}

1 个答案:

答案 0 :(得分:0)

最后,第二个重建代码确实有效,我猜其他地方还有一些东西......