Annotation of /benchmarks/programs/illust-vr/bmark-diderot.diderot

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Revision 1613 - (view) (download)

1 :	jhr	1581	// illust-vr
2 :			//
3 :			// Demonstration of "illustrative volume rendering"
4 :			//
5 :			// process output with:
6 :			// unu reshape -i illust-vr.txt -s 4 640 480 | overrgb -i - -b 0.1 0.15 0.2 -g 1.2 -o - | unu quantize -b 8 -min 0 -max 255 -o illust-vr.png
7 :
8 :			//field#2(3)[] F = bspln3 ⊛ load("../data/vfrhand-nohip.nhdr");
9 :	glk	1610	field#2(3)[] F = bspln3 ⊛ load("../../data/vfrhand-nohip-smooth.nrrd");
10 :	jhr	1581
11 :	glk	1610	field#0(1)[] silho = tent ⊛ load("../../data/txf/silho.nrrd");
12 :			field#0(1)[] shade = tent ⊛ load("../../data/txf/shade.nrrd");
13 :			field#0(2)[] rival = tent ⊛ load("../../data/txf/ridgvall.nrrd");
14 :			field#0(2)[] alpha = tent ⊛ load("../../data/txf/alpha-bone.nrrd"); // load("../data/txf/alpha-skin.nrrd");
15 :			field#0(1)[3] depth = tent ⊛ load("../../data/txf/depth.nrrd");
16 :	jhr	1581
17 :			// set camera, image, and rendering parameters
18 :			vec3 camEye = [127.331, -1322.05, 272.53];
19 :			vec3 camAt = [63.0, 82.6536, 98.0];
20 :			vec3 camUp = [0.9987, 0.0459166, -0.0221267];
21 :			real camNear = -78.0;
22 :			real camFar = 78.0;
23 :			real camFOV = 5.0;
24 :	glk	1610
25 :	jhr	1581	int imgResU = 640;
26 :			int imgResV = 480;
27 :			real rayStep = 0.15;
28 :	glk	1610	/*
29 :			int imgResU = 480;
30 :			int imgResV = 360;
31 :			real rayStep = 1.0;
32 :			*/
33 :	jhr	1581	vec3 lightVspDir = [-2.0, -3.0, -2.0];
34 :			real sthick = 0.4;
35 :			real refStep = 1.5;
36 :
37 :			// (boilerplate) computation of camera and light info
38 :			real camDist = |camAt - camEye|;
39 :			real camVspNear = camNear + camDist;
40 :			real camVspFar = camFar + camDist;
41 :			vec3 camN = normalize(camAt - camEye);
42 :			vec3 camU = normalize(camN × camUp);
43 :			vec3 camV = camN × camU;
44 :			real camVmax = tan(camFOV*π/360.0)*camDist;
45 :			real camUmax = camVmax*real(imgResU)/real(imgResV);
46 :			vec3 lightDir = normalize(lightVspDir[0]*camU +
47 :			lightVspDir[1]*camV +
48 :			lightVspDir[2]*camN);
49 :
50 :			strand RayCast (int ui, int vi) {
51 :			real rayU = lerp(-camUmax, camUmax, -0.5, real(ui), real(imgResU)-0.5);
52 :			real rayV = lerp(-camVmax, camVmax, -0.5, real(vi), real(imgResV)-0.5);
53 :			vec3 rayVec = (camDist*camN + rayU*camU + rayV*camV)/camDist;
54 :			vec3 vv = -normalize(rayVec);
55 :
56 :			real rayN = camVspNear;
57 :			real rayTransp = 1.0;
58 :			vec3 rayRGB = [0.0, 0.0, 0.0];
59 :			output vec4 outRGBA = [0.0, 0.0, 0.0, 0.0];
60 :
61 :			update {
62 :			vec3 pos = camEye + rayN*rayVec;
63 :			if (inside (pos,F)) {
64 :			real val = F(pos);
65 :			vec3 grad = -∇F(pos);
66 :			real gmag = |grad|;
67 :			real aa = alpha([max(0.0, min(2000.0, val)), max(0.0, min(900.0, gmag))]);
68 :			if (aa > 0.0) { // we have some opacity
69 :			vec3 norm = grad/gmag;
70 :			aa = 1.0 - pow(1.0-aa, rayStep/refStep);
71 :			real gray = 1.0;
72 :	jhr	1613	gray *= shade(norm • lightDir);
73 :	jhr	1581	tensor[3,3] Proj = identity[3];
74 :			tensor[3,3] Gten = identity[3];
75 :	jhr	1613	tensor[3,3] Hess = ∇⊗∇F(pos);
76 :			Proj = identity[3] - norm⊗norm;
77 :			Gten = -(Proj•Hess•Proj)/gmag;
78 :			real kv = max(0.0, min(1.0/sthick, (vv•Gten•vv)/(vv•Proj•vv)));
79 :			real vdn = vv•norm;
80 :			vdn = vdn*(1.0 + 2.0*vdn*vdn); // limit silhouette on front-facing surfaces
81 :			gray *= silho(max(0.0, min(2.0, vdn^2 + (sthick*(kv - 1.0/sthick))^2)));
82 :			real disc = max(0.0, sqrt(2.0*|Gten|^2 - trace(Gten)^2));
83 :			real k1 = (trace(Gten) + disc)/2.0;
84 :			real k2 = (trace(Gten) - disc)/2.0;
85 :			gray *= rival([min(0.55, |Gten|)/0.55, atan2(k2,k1)]);
86 :	jhr	1581	vec3 matRGB = depth(lerp(0.0, 1.0, camVspNear, rayN, camVspFar))
87 :			if useDepth else [1.0,1.0,1.0];
88 :			rayRGB = rayRGB + rayTransp*aa*gray*matRGB;
89 :			rayTransp = rayTransp*(1.0 - aa);
90 :			}
91 :			}
92 :			if (rayTransp < 0.01) { // early ray termination
93 :			rayTransp = 0.0;
94 :			stabilize;
95 :			}
96 :			if (rayN > camVspFar) {
97 :			stabilize;
98 :			}
99 :			rayN = rayN + rayStep;
100 :			}
101 :	glk	1610
102 :			stabilize {
103 :			rayRGB = 0.9*rayRGB;
104 :			outRGBA = [rayRGB[0], rayRGB[1], rayRGB[2], 1.0-rayTransp];
105 :			}
106 :	jhr	1581	}
107 :
108 :			initially [ RayCast(ui, vi) | vi in 0..(imgResV-1), ui in 0..(imgResU-1) ];

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