void ColouredCubicVoxelVP(
    float4 inPosition    : POSITION,
   float2 inMaterial    : TEXCOORD0,
   
    out float4 outClipPosition        : POSITION,
    out float4 outWorldPosition    : TEXCOORD0,
   out float2 outMaterial        : TEXCOORD1,
   
    uniform float4x4 world,
    uniform float4x4 viewProj
    )
{   
    //Compute the world space position
    outWorldPosition = mul(world, inPosition);   
   
    //Compute the clip space position
    outClipPosition = mul(viewProj, outWorldPosition);
   
   //Pass through the material
    outMaterial = inMaterial;
}

void ColouredCubicVoxelFP(
    float4 inPosition        : POSITION,
    float4 inWorldPosition    : TEXCOORD0,
    float4 inMaterial    : TEXCOORD1,

    uniform sampler2D heightMap : TEXUNIT0,
   
    out float4 result        : COLOR)
{   
   
   float3 worldNormal = cross(ddy(inWorldPosition.xyz), ddx(inWorldPosition.xyz));
   worldNormal = normalize(worldNormal);
   
    //World position is used as texture coordinates. Choose which
    //two components of world position to use based on normal. Could
    //optionally use a different texture for each face here as well.
   
   float2 uv;
   
   float materialID = inMaterial.x * 256.0 ;
   float atlasYOffset = floor(materialID / 16);
   float atlasXOffset = materialID - (atlasYOffset * 16);
   
   //testing
   //atlasXOffset = 5;
   //atlasYOffset = 1;
   
   
   if(worldNormal.x > 0.5){
        uv = inWorldPosition.yz;
    }
   
    if(worldNormal.x < -0.5){
        uv = inWorldPosition.yz;
    }
   
    if(worldNormal.y > 0.5){
        uv = inWorldPosition.xz;
    }
   
    if(worldNormal.y < -0.5){
        uv = inWorldPosition.xz;
    }
   
    if(worldNormal.z > 0.5){
        uv = inWorldPosition.xy;
    }
   
    if(worldNormal.z < -0.5){
        uv = inWorldPosition.xy;
    }
   uv = frac(uv / 16 + .5);
    uv = (float2(atlasXOffset, atlasYOffset) + float2(uv));
    uv = uv / 16;
   
   result = tex2D(heightMap, uv);
}

filtering anisotropic
                max_anisotropy 8