大气散射着色器中的伪影

我正在尝试实现在此处找到的大气散射着色器：https : //lightshaderdevlog.wordpress.com/

我已经在 GLSL 中实现了该算法，它看起来不错，但是由于某种原因呈现黑色工件：https : //imgur.com/a/CDrLt

似乎只有在查看特定的摄像机角度和那些特定的顶点时才会出现伪像。

这是我的代码：

顶点着色器

 #version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoord;
layout (location = 2) in vec3 aNormal;

// Vertex
uniform vec3 star_pos;      // point light source position (Sun) [GCS]
uniform vec3 planet_pos;    // planet center position [GCS]
uniform float overglow;     // cos(angle) of terminator propagation\

uniform mat4 modelView;
uniform mat4 projection;
uniform float og_farPlaneDistance;
uniform float u_logarithmicDepthConstant;

out vec3 lpos;          // point light source position (Sun) [camera space]
out vec3 ppos;          // planet center position [camera space]
out vec3 pixel_pos;     // fragment position [camera space]
out vec3 pixel_nor;     // fragment surface normal
out vec2 pixel_txy;     // fragment surface texture coord
out float angleIncidence;
out vec4 colAtmosphere;
out vec3 lightDir;

const float PI = 3.14159265f;
const float transitionWidth = 0.1f;
const float fresnelExponent = 20f;


vec4 modelToClipCoordinates(vec4 position, mat4 modelViewPerspectiveMatrix, float depthConstant, float farPlaneDistance){
    vec4 clip = modelViewPerspectiveMatrix * position;

    clip.z = ((2.0 * log(depthConstant * clip.z + 1.0) / log(depthConstant * farPlaneDistance + 1.0)) - 1.0) * clip.w;
    return clip;
}

void main()
    {


    lpos=(modelView*vec4(star_pos,1.0)).xyz;
    ppos=(modelView*vec4(planet_pos,1.0)).xyz;

    lightDir =normalize(lpos-ppos);

    pixel_pos=vec3(modelView*vec4(aPos,1.0));
    pixel_nor=mat3(transpose(inverse(modelView))) * aNormal;
    pixel_txy=aTexCoord;

    vec3 viewDir = normalize(-pixel_pos);


    angleIncidence = acos(dot(lightDir, pixel_nor)) / PI;

    float shadeFactor = 0.1 * (1 - angleIncidence) + 0.9 * (1 - (clamp(angleIncidence, 0.5, 0.5 + transitionWidth) - 0.5) / transitionWidth);

    float angleToViewer = sin(acos(dot(pixel_nor, viewDir)));

    float perspectiveFactor = 0.3 + 0.2 * pow(angleToViewer, fresnelExponent) + 0.5 * pow(angleToViewer, fresnelExponent * 20);

    colAtmosphere = vec4(perspectiveFactor*shadeFactor);

    gl_Position = modelToClipCoordinates(vec4(aPos, 1.0), projection * modelView, u_logarithmicDepthConstant, og_farPlaneDistance);
    }

片段着色器

#version 330 core
out vec4 FragColor;

// Fragment
uniform vec3 star_pos;      // point light source position (Sun) [GCS]
uniform vec3 planet_pos;    // planet center position [GCS]
//uniform vec3 planet_r;        // planet radius
uniform float overglow;     // cos(angle) of terminator propagation

uniform sampler2D diffuseTex;
uniform sampler2D txratm;
in vec3 lpos;           // point light source position (Sun) [camera space]
in vec3 ppos;           // planet center position [camera space]
in vec3 pixel_pos;      // fragment position [camera space]
in vec3 pixel_nor;      // fragment surface normal
in vec2 pixel_txy;      // fragment surface texture coord
in float angleIncidence;
in vec4 colAtmosphere;
in vec3 lightDir;

void main()
    {
    float li;
    vec3 c,lt_dir,c0;
    vec4 c1;
    lt_dir=lightDir; // vector from fragment to point light source
    li=dot(pixel_nor,lt_dir)+overglow;
    if (li<0.0) {
        li=0.0;
    }
    if (li>1.0) {
        li=1.0;
    }

    vec2 gradientLevel = vec2(angleIncidence, 0.5);
    c1 = colAtmosphere * texture(txratm, gradientLevel) * 1.4;

    c0=texture(diffuseTex,pixel_txy).rgb * li;

    c = c1.a * c1.rgb + (vec3(1.0, 1.0, 1.0) - c1.a) * c0;;


    FragColor=vec4(c,1.0);
//  gl_FragDepth=0.0;
    }