要减去背景图像的HLSL着色器

float Tolerance : register(C1);
SamplerState  ImageSampler : register(S0);
SamplerState  BackgroundSampler : register(S1);

struct VS_INPUT
{
    float4 Position : POSITION;
    float4 Diffuse  : COLOR0;
    float2 UV0      : TEXCOORD0;
    float2 UV1      : TEXCOORD1;
};

struct VS_OUTPUT
{
    float4 Position  : POSITION;
    float4 Color     : COLOR0;
    float2 UV        : TEXCOORD0;
};


float4 PS( VS_OUTPUT input ) : SV_Target
{
    float4 color = tex2D( ImageSampler, input.UV );
    float4 background = tex2D( BackgroundSampler, input.UV);

    if (abs(background.r - color.r) <= Tolerance && 
                  abs(background.g - color.g) <= Tolerance && 
                  abs(background.b - color.b) <= Tolerance)
    {
      color.rgba = 0;
    }

   return color;

}

要查看此示例,您需要一台带有摄像头的计算机:

1. http://xmldocs.net/alphavideo/background.html
2. 按[开始录制]。
3. 将身体移出场景,然后按[捕获背景]。