irrlicht引擎：镜子效果

float4x4    WorldViewProj; 
float4x4    MirrorWorldViewProj; 
struct VS_OUTPUT 
{ 
    float4 position    :POSITION; 

    float3 uv: TEXCOORD0; 
}; 

struct VS_INPUT 
{ 
    float4 position        : POSITION; 
    float4 color        : COLOR0; 
    float2 texCoord0    : TEXCOORD0; 
}; 

VS_OUTPUT main(VS_INPUT input) 
{ 
    VS_OUTPUT output;  
    float4 pos = mul(input.position, WorldViewProj); 
    output.position = pos;

    //计算反射纹理的坐标 

    pos = mul(input.position,MirrorWorldViewProj); 
    output.uv.x = 0.5 * (pos.w + pos.x); 
    output.uv.y = 0.5 * (pos.w - pos.y); 
    output.uv.z = pos.w; 
    return output; 
}

sampler2D colorMap; 
struct PS_OUTPUT 
{ 
    float4 color : COLOR0;   
}; 

struct PS_INPUT 
{ 
    float4 position    : POSITION; 
    float3 uv: TEXCOORD0; 
}; 
PS_OUTPUT main( PS_INPUT input ) 
{ 
    PS_OUTPUT output; 
    float2 uv = saturate(input.uv.xy / input.uv.z); 
    output.color = tex2D(colorMap,uv); 
    return output; 
}