使用directx9或DX11实现区域灯

Question

我想实现AreaLight使用Directx 9 Plz帮助我如何开始。我学两种三个联动，但能够在RenderMonkey的实现还是直接用样品

Answer 1

球形区域灯光HLSL

float specTrowbridgeReitz(float HoN,float a,float aP) 
{ 
    float a2 = a*a; 
    float ap2 = aP*aP; 
    return (a2 * ap2)/pow(HoN * HoN * (a2 - 1.0) + 1.0, 2.0); 
} 

float visSchlickSmithMod(float NoL, float NoV, float r) 
{ 
    float k = pow(r * 0.5 + 0.5, 2.0) * 0.5; 
    float l = NoL * (1.0 - k) + k; 
    float v = NoV * (1.0 - k) + k; 
    return 1.0/(4.0 * l * v); 
} 

float fresSchlickSmith(float HoV, float f0) 
{ 
    return f0 + (1.0 - f0) * pow(1.0 - HoV, 5.0); 
} 

float sphereLight(float3 pos,float3 N,float3 V,float3 r,float f0,float 
roughness,float NoV,out float NoL) 
{ 
    float3 L = lightPositions - pos; 
    float3 centerToRay = dot(L,r)*r-L; 
    float3 closestPoint = L + centerToRay * clamp(fLightRadius/length( 
    centerToRay), 0.0, 1.0); 
    float3 l = normalize(closestPoint); 
    float3 h = normalize(V+l); 
    NoL = clamp(dot(N,l),0.0,1.0); 
    float HoN = clamp(dot(h,N),0.0,1.0); 
    float HoV = dot(h,V); 
    float distL = length(L); 
    float alpha = roughness * roughness; 
    float alphaPrime = clamp(fLightRadius/(distL*2.0)+alpha,0.0,1.0); 
    float specD = specTrowbridgeReitz(HoN, alpha, alphaPrime); 
    float specF = fresSchlickSmith(HoV, f0); 
    float specV = visSchlickSmithMod(NoL, NoV, roughness); 
    return specD * specF * specV*NoL; 
} 

float3 areaLights(float3 pos,float3 nor,float3 V) 
{ 
    float f0 = FO; 
    float NoV = clamp(dot(nor,V),0.0,1.0); 
    float3 r = reflect(-V,nor); 
    float NdotLSphere; 
    float specSph = sphereLight(pos,nor,V,r,f0,roughness,NoV,NdotLSphere); 
    float3 color = 0.3183*(NdotLSphere*lightcolor)+ 
    (specSph*lightcolor)+albedo; 
    return pow(color,1.0/2.2); 
} 

float4 ps_main(PS_INPUT Input) : COLOR0 
{ 
    float3 N = normalize(Input.Normal); 
    float3 viewDir = normalize(campos.xyz - 
    float3(Input.WSPosition.xyz)); 
    float3 color = areaLights(Input.WSPosition,N,viewDir); 
    return float4(color,0.0); 
}