如何修复错误的Blinn-Phong照明

我正在尝试为Vulkan着色器中的单个光源实施Blinn-Phong着色，但是我得到的结果不是我期望的。

输出如下所示：

灯光位置应位于相机右侧的后方，该位置正确地显示在头上，而不是圆圈上。我不希望圆圈中间有高强度的点。

灯光位置在坐标（10、10、10）处。

圆中间的高强度点是（0,0,0）。

顶点着色器：

#version 450
#extension GL_ARB_separate_shader_objects : enable

layout(binding = 0) uniform MVP {
    mat4 model;
    mat4 view;
    mat4 proj;
} mvp;

layout(location = 0) in vec3 inPosition;
layout(location = 1) in vec3 inColor;
layout(location = 2) in vec2 inTexCoord;
layout(location = 3) in vec3 inNormal;

layout(location = 0) out vec3 fragColor;
layout(location = 1) out vec2 fragTexCoord;
layout(location = 2) out vec3 Normal;
layout(location = 3) out vec3 FragPos;
layout(location = 4) out vec3 viewPos;

void main() {
    gl_Position = mvp.proj * mvp.view * mvp.model * vec4(inPosition, 1.0);
    fragColor = inColor;
    fragTexCoord = inTexCoord;
    Normal = inNormal;
    FragPos = inPosition;
    viewPos = vec3(mvp.view[3][0], mvp.view[3][1], mvp.view[3][2]);
}

片段着色器：

#version 450
#extension GL_ARB_separate_shader_objects : enable

layout(binding = 1) uniform sampler2D texSampler;
layout(binding = 2) uniform LightUBO{
    vec3 position;
    vec3 color;
} Light;

layout(location = 0) in vec3 fragColor;
layout(location = 1) in vec2 fragTexCoord;
layout(location = 2) in vec3 Normal;
layout(location = 3) in vec3 FragPos;
layout(location = 4) in vec3 viewPos;

layout(location = 0) out vec4 outColor;

void main() {
    vec3 color = texture(texSampler, fragTexCoord).rgb;
    // ambient
    vec3 ambient = 0.2 * color;

    // diffuse
    vec3 lightDir = normalize(Light.lightPos - FragPos);
    vec3 normal = normalize(Normal);
    float diff = max(dot(lightDir, normal), 0.0);
    vec3 diffuse = diff * color;

    // specular
    vec3 viewDir = normalize(viewPos - FragPos);
    vec3 reflectDir = reflect(-lightDir, normal);
    float spec = 0.0;
    vec3 halfwayDir = normalize(lightDir + viewDir);  
    spec = pow(max(dot(normal, halfwayDir), 0.0), 32.0);

    vec3 specular = vec3(0.25) * spec;
    outColor = vec4(ambient + diffuse + specular, 1.0);
}

注意：我正在尝试将本教程中的着色器实现到Vulkan中。