// vr.diderot
//
// maximum intensity projection in Diderot
//

input string dataFile;		// name of dataset
input real stepSz;		// size of steps
input vec<3> light;
input int wid = 640;
input int ht = 480;

image[3] img = load (dataFile);

field#1[3] F = convolve (bspln3, img);
 
actor RayCast (int row, int col)
{
    vec<3>	dir = (real(row), real(col), 0.0);
    vec<3>	pos = (0.0, 0.0, 0.0);
    real	t = 0.0;
    real        maxval = -inf; 
    int         num = 0;

    update
    {
	vec<3> pt = pos + t*dir;
	real val = F@pt;
        maxval = max(val, maxval);
	if (t > 1)
	    stabilize;
	t = t + stepSz;
        num = num + 1;
    }

    /* render: output maxval */
}