struct vertexOut
{
    float4 position : POSITION;
    float2 uv : TEXCOORD0;
    float3 worldNormal : TEXCOORD1;
    float3 worldView : TEXCOORD2;
};

float4 main(vertexOut input, uniform float alphaValue, uniform float cutoffAngle, uniform float exponent, uniform float time, uniform float4 color) : COLOR
{
    float3 Nn = normalize(input.worldNormal);
    float3 Vn = normalize(input.worldView);
    float alphaMod = dot(Nn, Vn);//this is a measure for how close we are to the edge of a model according to our view
    float cutoff=cos(cutoffAngle * 3.14 / 180.0);//pi divided by 180
    if(alphaMod<cutoff)//transform output range so it only affects angles close to 90 degrees
    {
        alphaMod/=cutoff;
    }
    else
    {
        alphaMod=1.0;
    }
    alphaMod = pow(alphaMod,exponent); //how fast should the intensity of the glow decrease
    color.w = alphaMod * alphaValue * ((sin(time)/3.14 + 1.0) / 2.0 + 0.1);
    return color;
}