GLSL每像素照明问题

我有每像素照明的问题，因为光越来越接近对象，它开始做奇怪的事情，像https://i.stack.imgur.com/M8Txl.jpg。

当相机离得太近时，我也会得到这样的伪影https://i.stack.imgur.com/8KB67.jpg。

VertShader:

#version 330 core
layout(location = 0) in vec3 vertexPosition_modelspace;
layout(location = 1) in vec4 vertexColor;
layout(location = 2) in vec2 vertexTexCord;
layout(location = 3) in vec3 vertexNormal;
uniform mat4 MVP;
uniform mat4 V;
uniform mat4 P;
uniform mat4 M;
uniform vec3 PointLight1_Position;
out vec4 fragmentColor;
out vec2 UV;
out vec3 Position_worldspace;
out vec3 Normal_cameraspace;
out vec3 EyeDirection_cameraspace;
out vec3 LightDirection_cameraspace;
void main(){
    gl_Position =  MVP * vec4(vertexPosition_modelspace,1);
    Position_worldspace = ( M * vec4(vertexPosition_modelspace,1)).xyz;
    vec3 vertexPosition_cameraspace = ( V * M * vec4(vertexPosition_modelspace,1)).xyz;
    EyeDirection_cameraspace = - vertexPosition_cameraspace;
    vec3 LightPosition_cameraspace = ( V * vec4(PointLight1_Position,1)).xyz;
    LightDirection_cameraspace = LightPosition_cameraspace + EyeDirection_cameraspace;
    vec3 NormalPosition_cameraspace = ( V * M * vec4(vertexNormal,1)).xyz;
    Normal_cameraspace = -NormalPosition_cameraspace;

    fragmentColor = vertexColor;
    UV = vertexTexCord;
}

片段着色器:

#version 330 core
in vec4 fragmentColor;
in vec2 UV;
in vec3 Position_worldspace;
in vec3 Normal_cameraspace;
in vec3 EyeDirection_cameraspace;
in vec3 LightDirection_cameraspace;
out vec3 color;
uniform sampler2D TextureSampler1;
uniform vec3 PointLight1_Position;
void main()
{
    vec3 LightColor = vec3(1,1,1);
    float LightPower = 10.0f;
    vec3 MaterialDiffuseColor = texture2D(TextureSampler1, UV).rgb * fragmentColor.rgb;
    vec3 MaterialAmbientColor = vec3(0.1,0.1,0.1) * MaterialDiffuseColor;
    vec3 MaterialSpecularColor = vec3(0.3,0.3,0.3);
    float distance = length( PointLight1_Position - Position_worldspace );
    vec3 n = normalize( Normal_cameraspace );
    vec3 l = normalize( LightDirection_cameraspace );
    float cosTheta = clamp( dot( n,l ), 0,1 );
    vec3 E = normalize(EyeDirection_cameraspace);
    vec3 R = reflect(-l,n);
    float cosAlpha = clamp( dot( E,R ), 0,1 );
    color = 
        MaterialAmbientColor +
        MaterialDiffuseColor * LightColor * LightPower * cosTheta / (distance*distance) +
        MaterialSpecularColor * LightColor * LightPower * pow(cosAlpha,5) / (distance*distance);
}