1 : |
glk |
46 |
// vr.diderot
|
2 : |
|
|
//
|
3 : |
|
|
// volume rendering example in Diderot
|
4 : |
|
|
//
|
5 : |
|
|
|
6 : |
|
|
input string dataFile; // name of dataset
|
7 : |
|
|
input real stepSz; // size of steps
|
8 : |
jhr |
51 |
input vec3 lightDir;
|
9 : |
jhr |
87 |
input vec3 lightRGB;
|
10 : |
jhr |
51 |
input vec3 eye; // location of eye point
|
11 : |
|
|
input vec3 orig; // location of pixel (0,0)
|
12 : |
|
|
input vec3 cVec; // vector between pixels horizontally
|
13 : |
|
|
input vec3 rVec; // vector between pixels vertically
|
14 : |
jhr |
87 |
input real ka;
|
15 : |
|
|
input real kd;
|
16 : |
|
|
input real ks;
|
17 : |
|
|
input real sh;
|
18 : |
glk |
46 |
|
19 : |
jhr |
51 |
image(3)[] img = load (dataFile);
|
20 : |
glk |
46 |
|
21 : |
jhr |
104 |
//field#1(3)[] F = convolve (bspln3, img);
|
22 : |
|
|
field#2(3)[] F = convolve (bspln3, img);
|
23 : |
glk |
49 |
|
24 : |
glk |
52 |
field#0(1)[4] txf = convolve (tent, load("txf-rgba.nrrd"));
|
25 : |
glk |
46 |
|
26 : |
|
|
actor RayCast (int row, int col)
|
27 : |
|
|
{
|
28 : |
jhr |
59 |
vec3 pos = orig + real(row)*rVec + real(col)*cVec;
|
29 : |
glk |
54 |
vec3 dir = (pos - eye)/|pos - eye|;
|
30 : |
glk |
46 |
real t = 0.0;
|
31 : |
jhr |
163 |
output vec3 rayRGB = [0.0, 0.0, 0.0];
|
32 : |
glk |
46 |
real rayTransp = 1.0;
|
33 : |
|
|
|
34 : |
|
|
update
|
35 : |
|
|
{
|
36 : |
|
|
if (inside (pos,F)) {
|
37 : |
|
|
real val = F@pos;
|
38 : |
jhr |
51 |
vec3 grad = (D F)@pos;
|
39 : |
|
|
vec3 norm = grad/|grad|;
|
40 : |
jhr |
87 |
vec3 halfDir = (lightDir - dir)/|lightDir - dir|;
|
41 : |
jhr |
86 |
vec4 matRGBA = txf@[val];
|
42 : |
|
|
vec3 matRGB = [matRGBA[0],matRGBA[1],matRGBA[2]];
|
43 : |
jhr |
87 |
real ldotn = dot(lightDir, norm);
|
44 : |
|
|
real hdotn = dot(halfDir, norm);
|
45 : |
jhr |
90 |
vec3 pntRGB = (ka + kd*ldotn)*modulate(matRGB,lightRGB) + ks*pow(hdotn,sh)*lightRGB;
|
46 : |
jhr |
87 |
rayRGB = rayRGB + rayTransp*matRGBA[3]*pntRGB;
|
47 : |
|
|
rayTransp = rayTransp*(1.0 - matRGBA[3]);
|
48 : |
glk |
46 |
}
|
49 : |
|
|
if (t > 1.0 || rayTransp < 0.01) // a little odd; ray terminates at length=1
|
50 : |
|
|
stabilize;
|
51 : |
|
|
pos = pos + stepSz*dir;
|
52 : |
|
|
t = t + stepSz;
|
53 : |
|
|
}
|
54 : |
|
|
|
55 : |
jhr |
90 |
}
|
56 : |
glk |
46 |
|
57 : |
jhr |
90 |
initially [ RayCast(r, c) | r in 0..1023, c in 0..1023 ];
|