cbuffer cbPerObject : register(b0)
{
float4x4 gWorldView;
};
cbuffer cbPass : register(b1)
{
float4x4 gWorldViewProj;
};
struct VertexIn
{
float3 PosL : POSITION;
float3 Normal : NORMAL;
};
struct VertexOut
{
float4 PosH : SV_POSITION;
float3 tNormal : NORMAL;
float3 PosW : POSITION;
float3 LightPos: POSITION1;
};
static float3 LightPos = { 0.0f, 10.0f, 0.0f };
static float3 DiffuseLightColor = { 1.0f, 1.0f, 0.5f };
static float FallOfStart = 15;
static float FallOfEnd = 15;
static float SpotPower = 0.00001;
static float3 LightDirection = { 5.0f, -5.0f, 0.0f };
VertexOut VS(VertexIn vin)
{
VertexOut vout;
vout.PosH = mul(float4(vin.PosL, 1.0f), gWorldViewProj);
float4 PosW = mul(float4(vin.PosL, 1.0f), gWorldView);
vout.PosW = PosW.xyz;
vout.tNormal = mul(vin.Normal, (float3x3)gWorldView);
vout.LightPos = mul(float4(LightPos, 1.0f), gWorldView);
return vout;
}
float CalcAttenuation(float d, float falloffStart, float falloffEnd)
{
return saturate((falloffEnd-d) / (falloffEnd – falloffStart));
}
float3 Get_Spot_Light(float3 tNormal, float3 PosW, float3 LightPosW)
{
float3 ToLightPos = LightPosW – PosW;
float Dist = length(ToLightPos);
if(Dist > FallOfEnd)
return 0;
ToLightPos = normalize(ToLightPos);
float3 Normal = normalize(tNormal);
float Dot = max(dot(ToLightPos, Normal), 0.0f);
float AttVal = CalcAttenuation(Dist, FallOfStart, FallOfEnd);
LightDirection = normalize(LightDirection);
float SpotFactor = pow(max(dot(-ToLightPos, LightDirection), 0.0f), SpotPower);
return DiffuseLightColor * AttVal * SpotFactor * Dot;
}
float4 PS(VertexOut pin) : SV_Target
{
float3 ResColor = Get_Spot_Light(pin.tNormal, pin.PosW, pin.LightPos);
return float4(ResColor, 1.0f);
}
I’m making Spot light DirectX12, here’s a screenshot:
I don’t understand – the documentation says that a spot light is the light from a flashlight, that is, if the flashlight is located at an angle to the surface, then there should be an (approximately) oval spot of light. There is a non-oval spot of light on my screenshot. Here is my shader (works for other light sources, tested) explain where I made a mistake so that the light spot would be oval.