1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
#include "VoxelStepper.h"
using namespace SyntopiaCore::Math;
namespace SyntopiaCore {
namespace GLEngine {
VoxelStepper::VoxelStepper(Vector3f minPos, Vector3f maxPos, int steps)
: steps(steps), minPos(minPos), maxPos(maxPos), size(( maxPos - minPos)/(double)steps) {
currentT = 0;
copy = false;
grid = new QList<Object3D*>[steps*steps*steps];
for (int i = 0; i < steps*steps*steps; i++) grid[i] = QList<Object3D*>();
};
VoxelStepper::~VoxelStepper() { if (!copy) delete[] grid; };
void VoxelStepper::registerObject(Object3D* obj) {
// Simple method - check all cells intersecting the objects bounding boxes.
obj->prepareForRaytracing();
Vector3f from;
Vector3f to;
obj->getBoundingBox(from,to);
from = from - minPos;
to = to - minPos;
int xStart = floor(from.x()/size.x());
int xEnd = ceil(to.x()/size.x());
int yStart = floor(from.y()/size.y());
int yEnd = ceil(to.y()/size.y());
int zStart = floor(from.z()/size.z());
int zEnd = ceil(to.z()/size.z());
if (xStart < 0) xStart = 0;
if (yStart < 0) yStart = 0;
if (zStart < 0) zStart = 0;
if (xEnd > (int)steps) xEnd = steps;
if (yEnd > (int)steps) yEnd = steps;
if (zEnd > (int)steps) zEnd = steps;
for (unsigned int x = xStart; x < (unsigned int)xEnd; x++) {
for (unsigned int y = yStart; y < (unsigned int)yEnd; y++) {
for (unsigned int z = zStart; z < (unsigned int)zEnd; z++) {
if (obj->intersectsAABB(minPos + Vector3f(size.x()*x,size.y()*y,size.z()*z),minPos + Vector3f(size.x()*(x+1),size.y()*(y+1),size.z()*(z+1)) )) {
grid[x+y*steps+z*steps*steps].append(obj);
}
}
}
}
}
QList<Object3D*>* VoxelStepper::setupRay(Vector3f pos, Vector3f dir, double& maxT) {
this->pos = pos;
this->dir = dir;
currentT = 0;
const Vector3f ro = pos - minPos;
cx = floor(ro.x() / size.x());
cy = floor(ro.y() / size.y());
cz = floor(ro.z() / size.z());
if ((cx < 0 || cx >= steps) ||
(cy < 0 || cy >= steps) ||
(cz < 0 || cz >= steps)) {
// we are outside grid.
// advance ray to inside grid.
bool found = false;
double p;
if (dir.x() > 0) {
p = (minPos.x()-pos.x())/dir.x();
cx = 0;
} else {
p = (maxPos.x()-pos.x())/dir.x();
cx = steps-1;
}
Vector3f v = pos + dir*p - minPos;
cy = floor(v.y() / size.y());
cz = floor(v.z() / size.z());
if ((cy >= 0 && cy < steps) && (cz >= 0 && cz < steps)) {
found = true;
pos = v+minPos;
}
if (!found) {
if (dir.y() > 0) {
p = (minPos.y()-pos.y())/dir.y();
cy = 0;
} else {
p = (maxPos.y()-pos.y())/dir.y();
cy = steps-1;
}
Vector3f v = pos + dir*p - minPos;
cx = floor(v.x() / size.x());
cz = floor(v.z() / size.z());
if ((cx >= 0 && cx < steps) && (cz >= 0 && cz < steps)) {
pos = v+minPos;
found = true;
}
}
if (!found) {
if (dir.z() > 0) {
p = (minPos.z()-pos.z())/dir.z();
cz = 0;
} else {
p = (maxPos.z()-pos.z())/dir.z();
cz = steps-1;
}
Vector3f v = pos + dir*p - minPos;
cx = floor(v.x() / size.x());
cy = floor(v.y() / size.y());
if ((cy >= 0 && cy < steps) && (cx >= 0 && cx < steps)) {
pos = v+minPos;
found = true;
}
}
currentT = p;
// We do not intersect grid.
if (!found) return false;
}
stepX = (dir.x() > 0) ? 1 : -1;
stepY = (dir.y() > 0) ? 1 : -1;
stepZ = (dir.z() > 0) ? 1 : -1;
tDeltaX = stepX*size.x() / dir.x();
tDeltaY = stepY*size.y() / dir.y();
tDeltaZ = stepZ*size.z() / dir.z();
Vector3f orv = pos- (minPos + Vector3f(size.x()*cx, size.y()*cy, size.z()*cz));
tMaxX = stepX*orv.x()/dir.x();
if (stepX>0) tMaxX = tDeltaX - tMaxX;
tMaxY = stepY*orv.y()/dir.y();
if (stepY>0) tMaxY = tDeltaY - tMaxY;
tMaxZ = stepZ*orv.z()/dir.z();
if (stepZ>0) tMaxZ = tDeltaZ - tMaxZ;
// Now pos is advanced properly.
// cx,cy,cz contains current cell.
QList<Object3D*>* list = &grid[cx+cy*steps+cz*steps*steps];
if (list && (list->count() == 0)) {
list = advance(maxT);
} else {
maxT = currentT + minn(tMaxX, tMaxY, tMaxZ);
}
return list;
}
QList<Object3D*>* VoxelStepper::advance(double& maxT) {
QList<Object3D*>* list = 0;
do {
if(tMaxX < tMaxY) {
if(tMaxX < tMaxZ) {
cx += stepX;
if (cx >= steps || cx < 0) return 0;
tMaxX = tMaxX + tDeltaX;
} else {
cz += stepZ;
if (cz >= steps || cz < 0) return 0;
tMaxZ = tMaxZ + tDeltaZ;
}
} else {
if(tMaxY < tMaxZ) {
cy += stepY;
if (cy >= steps || cy < 0) return 0;
tMaxY = tMaxY + tDeltaY;
} else {
cz += stepZ;
if (cz >= steps || cz < 0) return 0;
tMaxZ = tMaxZ + tDeltaZ;
}
}
list = &grid[cx+cy*steps+cz*steps*steps];
if (list && (list->count() == 0)) list = 0; // Continue until we find an non-empty list.
} while(list == 0);
maxT = currentT + minn(tMaxX, tMaxY, tMaxZ);
return(list);
}
}
}
|
