vector pcfilter2 ( int input; int pts [ ]; float dist [ ]; string attrib )
{
    float sum = 0, w, d;
    vector value, result = 0;
    float maxd = dist [ -1 ];
    int count = len ( pts );
    for ( int i = 0; i < count; ++i )
    {
        value = point ( input, attrib, pts [ i ] );
        w = 1 - smooth ( 0, 1.1 * maxd, dist [ i ] );
        sum += w;
        result += w * value;
    }
    result /= sum;
    return result;
}

float radius = ch("r");
int maxpts = chi("maxpts");
float dist [ ] = { };
int pts [ ] = pcfind ( 0, "P", @P, radius, maxpts, dist );
vector blurred = pcfilter2 ( 0, pts, dist, "P" );
@P += ( @P - blurred ) * ch("amount");