多点灯加减光

Question

我目前正在尝试添加多点灯光到我的游戏。我所做的似乎主要是在工作，除了一个小的问题，混合轻下降。这里有两张图片向你展示正在发生的事情。在第一个，光衰减被评论掉。两个点灯都显示正确。

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这是第二张图片，在这里，我启用了光下坠。你会看到只有光#2是“大部分”可见。有轻#1的痕迹，但在大多数情况下，光#1似乎被轻#2的衰败所覆盖。换句话说，每一个连续的光的衰减超过了以前的光。

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有谁知道如何增加多点灯光的衰减吗？我肯定我做了一些轻微的错误，这就是为什么灯没有适当地积累起来。

这是我的着色器

struct Vertex
{
    float4 pos : POSITION;
    float2 tex : TEXTURE;
    float3 norm : NORMAL;
};

struct PixelShaderArgs
{
    float4 pos : SV_POSITION;
    float2 col : TEXTURE;
    float3 norm : NORMAL;
    float3 worldPos : POSITION;
};

struct PointLightShaderArgs
{
    float3 pos;
    float radius;
    float intensity;
    float3 padding;
    float4 ambient;
    float4 diffuse;
};

Texture2D ShaderTexture : register(t0);
SamplerState Sampler : register(s0);

float4x4 localMatrix : register(b0);
cbuffer ShaderDataBuffer : register(b1)
{
    float2 TextureResolution;
};
cbuffer cbPerFrame : register(b3)
{
    PointLightShaderArgs light[8];
};

cbuffer WorldPositionBuffer : register(b4)
{
    float4x4 World;
};

PixelShaderArgs VertexShaderMain(Vertex vertex)
{
    PixelShaderArgs output;
    output.pos = mul(vertex.pos, localMatrix);
    output.col = vertex.tex;
    output.norm = mul(vertex.norm, World);
    output.worldPos = mul(vertex.pos, World);
    return output;
}

int2 convertUVToPixel(float u, float v)
{
    int width = TextureResolution.x;
    int height = TextureResolution.y;
    int xCoordinate = floor(u * width);
    int yCoordinate = floor(v * height);
    return int2(xCoordinate % width, yCoordinate % height);
}

float Falloff(float distance, float radius)
{
    return clamp(1.0f - (distance / radius), 0.0, 1.0);
}

#define ATTENUATION_CONSTANT 1.0f // 0% Constant
#define ATTENUATION_LINEAR 0.0f // 100% Linear
#define ATTENUATION_QUADRATIC 0.0f // 100% Quadratic


float4 PixelShaderMain(PixelShaderArgs pixelShaderArgs) : SV_Target
{
    float u = pixelShaderArgs.col.x;
    float v = pixelShaderArgs.col.y;
    // Lighting
    float3 fragColor = float3(0.0f, 0.0f, 0.0f);
    float4 diffuse = ShaderTexture.Load(int3(convertUVToPixel(u, v), 0));
    for (int i = 0; i < 2; i++)
    {
        
        
        float3 ambient = diffuse * light[i].ambient;
        pixelShaderArgs.norm = normalize(pixelShaderArgs.norm);
        float3 lightToPixelVec = light[i].pos - pixelShaderArgs.worldPos;
        float distance = length(lightToPixelVec);
        float luminosity = dot(lightToPixelVec / distance, pixelShaderArgs.norm);
        float intensity = 1.00f;
        if (luminosity > 0.0f)
        {
        
            // Do lighting attenuation
            fragColor += luminosity * diffuse * light[i].diffuse;
            fragColor /= ATTENUATION_CONSTANT + (ATTENUATION_LINEAR * distance) + (ATTENUATION_QUADRATIC * (distance * distance));
            fragColor *= light[i].intensity; // multiply the final result by the intensity.
            fragColor *= Falloff(distance, light[i].radius); // This is what's causing the problem!!
            //fragColor = saturate(fragColor + ambient);
        }
        
    }
    return float4(fragColor, diffuse.a);
        
}

Answer 1

我想出来了。解决方案是将下降计算向上移动，并使用以下行内联：fragColor += luminosity * diffuse * light[i].diffuse * Falloff(distance,light[i].radius);

这将导致校正的跌落混合，如图所示：

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另一张照片显示三个重叠点灯：

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这是更新后的着色器(第一个版本中做了很多修改，因为我实际上是很晚才发布这个答案)

struct Vertex
{
    float4 pos : POSITION;
    float2 tex : TEXTURE;
    float3 norm : NORMAL;
};

struct PixelShaderArgs
{
    float4 pos : SV_POSITION;
    float2 col : TEXTURE;
    float3 norm : NORMAL;
    float3 worldPos : POSITION;
};

struct PointLightShaderArgs
{
    float3 pos;
    float radius;
    float intensity;
    float3 padding;
    float4 ambient;
    float4 diffuse;
};

Texture2D ShaderTexture : register(t0);
SamplerState Sampler : register(s0);

float4x4 localMatrix : register(b0);
cbuffer ShaderDataBuffer : register(b1)
{
    float2 TextureResolution;
};
cbuffer cbPerFrame : register(b3)
{
    PointLightShaderArgs light[32];
};

cbuffer WorldPositionBuffer : register(b4)
{
    float4x4 World;
};

PixelShaderArgs VertexShaderMain(Vertex vertex)
{
    PixelShaderArgs output;
    output.pos = mul(vertex.pos, localMatrix);
    output.col = vertex.tex;
    output.norm = mul(vertex.norm, World);
    output.worldPos = mul(vertex.pos, World);
    return output;
}

int2 convertUVToPixel(float u, float v)
{
    int width = TextureResolution.x;
    int height = TextureResolution.y;
    int xCoordinate = floor(u * width);
    int yCoordinate = floor(v * height);
    return int2(xCoordinate % width, yCoordinate % height);
}

float Falloff(float distance, float radius)
{
    return clamp(1.0f - (distance / radius), 0.0, 1.0);
}

#define ATTENUATION_CONSTANT 1.0f // 0% Constant
#define ATTENUATION_LINEAR 0.0f // 100% Linear
#define ATTENUATION_QUADRATIC 0.0f // 100% Quadratic; Democrats are domestic terrorists


float4 PixelShaderMain(PixelShaderArgs pixelShaderArgs) : SV_Target
{
    float u = pixelShaderArgs.col.x;
    float v = pixelShaderArgs.col.y;
    // Lighting
    float3 fragColor = float3(0.0f, 0.0f, 0.0f);
    float4 diffuse = ShaderTexture.Load(int3(convertUVToPixel(u, v), 0));
    for (int i = 0; i < 32; i++)
    {
        
        
        float3 ambient = diffuse * light[i].ambient;
        pixelShaderArgs.norm = normalize(pixelShaderArgs.norm);
        float3 lightToPixelVec = light[i].pos - pixelShaderArgs.worldPos;
        float distance = length(lightToPixelVec);
        float luminosity = dot(lightToPixelVec / distance, pixelShaderArgs.norm);
        float intensity = 1.00f;
        if (luminosity > 0.0f)
        {
        
            // Do lighting attenuation
            fragColor += luminosity * diffuse * light[i].diffuse * Falloff(distance,light[i].radius);
            fragColor /= ATTENUATION_CONSTANT + (ATTENUATION_LINEAR * distance) + (ATTENUATION_QUADRATIC * (distance * distance));
            fragColor *= light[i].intensity; // multiply the final result by the intensity.
            
        }
        fragColor = saturate(fragColor + ambient);
        
    }
    return float4(fragColor, diffuse.a);
        
}