光线追踪中的正交投影

Question

我在 vulkan 有一个基于透视投影的光线追踪渲染器，我想将其转换为正交投影，我尝试用正交投影矩阵替换透视投影矩阵，并将光线原点作为像素坐标，但似乎没有工作，显然有些问题。

    uint randSeed = initRand(gl_LaunchIDEXT.x + gl_LaunchIDEXT.y * gl_LaunchSizeEXT.x, ubo.frameID, 16);

    //vec4 origin           = ubo.viewInverse * vec4(0.0, 0.0, 0.0, 1.0); //for perpective
    vec4 origin         = ubo.viewInverse * vec4(gl_LaunchIDEXT.x, gl_LaunchIDEXT.y, 0.0,  1.0); //for ortho

    // ---- [Apply jitter to anti alias] ---- 
    vec2 jitter         = vec2(nextRand(randSeed), nextRand(randSeed)) - 0.5;
    //vec4 target           = ubo.projInverse * vec4((gl_LaunchIDEXT.xy + jitter) / gl_LaunchSizeEXT.xy * 2.0 - 1.0, 0.0, 1.0); //for perpective
    vec4 target = ubo.orthoInverse * vec4((gl_LaunchIDEXT.xy + jitter) / gl_LaunchSizeEXT.xy * 2.0 - 1.0, 0.0, 1.0); //for ortho
    vec4 direction = ubo.viewInverse * vec4(normalize(target.xyz), 0.0);

我正在使用 glm::ortho 函数计算正交矩阵， 我也尝试使用下面的代码进行计算，但我没有得到所需的结果 -

// set the OpenGL orthographic projection matrix
void glOrtho(
    in float b, in float t, in float l, in float r,
    in float n, in float f,
    inout mat4 M)
{
    // set OpenGL perspective projection matrix
    M[0][0] = 2 / (r - l);
    M[0][1] = 0;
    M[0][2] = 0;
    M[0][3] = 0;

    M[1][0] = 0;
    M[1][1] = 2 / (t - b);
    M[1][2] = 0;
    M[1][3] = 0;

    M[2][0] = 0;
    M[2][1] = 0;
    M[2][2] = -2 / (f - n);
    M[2][3] = 0;

    M[3][0] = -(r + l) / (r - l);
    M[3][1] = -(t + b) / (t - b);
    M[3][2] = -(f + n) / (f - n);
    M[3][3] = 1;
}

如何解决这个问题？