Why specular reflection work only in center of virtual scene?

Question

How to calculate this cpecular reflection?

HLSL

void calculateSpecular(
    in float4 Normal,
    in float4 SunLightDir,
    inout float4 Specular
){
        Specular = specularLevel * pow(saturate(dot(reflect(normalize(abs(eyePosition)), Normal), SunLightDir)), specularExponent);
}

/// in pixel shader
float4 Specular = float4(0.f,0.f,0.f,1.f);
calculateSpecular( input.normal, -sunLightDir, Specular );

///sunLightDir it's just camera position + vec3(0,10,0)

/// in vertex shader
output.normal = mul( float4( input.normal, 0.f ) , World );

Answer 1

Do not forget about the different types of light sources.

This article helped me solve the problem.

https://www.3dgep.com/texturing-lighting-directx-11/