// vr-MIP.diderot
//
// maximum intensity projection in Diderot
//
input string dataFile; // name of dataset
input real stepSz; // size of steps
// e.g. 0.1
input vec3 eye; // location of eye point
// e.g. (25,15,10)
input vec3 orig; // location of pixel (0,0)
// e.g. (12.1373,4.78258,8.3972)
input vec3 cVec; // vector between pixels horizontally
// e.g. (-0.0135258,0.0247972,0)
input vec3 rVec; // vector between pixels vertically
// e.g. (0.00667124,0.00363886,-0.0272048)
image(3)[] img = load (dataFile);
//field#1(3)[] F = convolve (bspln3, img);
field#2(3)[] F = convolve (bspln3, img);
actor RayCast (int row, int col)
{
vec3 pos = orig + real(row)*rVec + real(col)*cVec;
vec3 dir = (pos - eye)/|pos - eye|;
real t = 0.0;
real maxval = -inf;
update
{
vec3 pt = pos + t*dir;
real val = F@pt;
maxval = max(val, maxval);
if (t > 20)
stabilize;
t = t + stepSz;
}
/* render: output maxval */
}
initially [ RayCast(r, c) | r in 0..199, c in 0..199 ];