-
Notifications
You must be signed in to change notification settings - Fork 37
/
Copy pathtiny_bvh_collide.cpp
182 lines (163 loc) · 6.29 KB
/
tiny_bvh_collide.cpp
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
#define FENSTER_APP_IMPLEMENTATION
#define SCRWIDTH 800
#define SCRHEIGHT 600
#define TILESIZE 20
#include "external/fenster.h" // https://github.com/zserge/fenster
#define TINYBVH_IMPLEMENTATION
#define INST_IDX_BITS 8 // override default; space for 256 instances.
#include "tiny_bvh.h"
#include <fstream>
#include <thread>
using namespace tinybvh;
struct Sphere { bvhvec3 pos; float r; };
BVH sponza, obj, tlas;
BVHBase* bvhList[] = { &sponza, &obj };
BLASInstance inst[2];
int frameIdx = 0, verts = 0;
bvhvec4* triangles = 0;
Sphere* spheres = 0;
static std::atomic<int> tileIdx( 0 );
static unsigned threadCount = std::thread::hardware_concurrency();
// setup view pyramid for a pinhole camera
static bvhvec3 eye( -15.24f, 21.5f, 2.54f ), p1, p2, p3;
static bvhvec3 view = tinybvh_normalize( bvhvec3( 0.826f, -0.438f, -0.356f ) );
// callback for custom geometry: ray/sphere intersection
bool sphereIntersect( tinybvh::Ray& ray, const unsigned primID )
{
bvhvec3 oc = ray.O - spheres[primID].pos;
float b = tinybvh_dot( oc, ray.D ), r = spheres[primID].r;
float c = tinybvh_dot( oc, oc ) - r * r, t, d = b * b - c;
if (d <= 0) return false;
d = sqrtf( d ), t = -b - d;
bool hit = t < ray.hit.t && t > 0;
if (hit) ray.hit.t = t, ray.hit.prim = primID;
return hit;
}
bool sphereIsOccluded( const tinybvh::Ray& ray, const unsigned primID )
{
bvhvec3 oc = ray.O - spheres[primID].pos;
float b = tinybvh_dot( oc, ray.D ), r = spheres[primID].r;
float c = tinybvh_dot( oc, oc ) - r * r, t, d = b * b - c;
if (d <= 0) return false;
d = sqrtf( d ), t = -b - d;
return t < ray.hit.t && t > 0;
}
void sphereAABB( const unsigned primID, bvhvec3& boundsMin, bvhvec3& boundsMax )
{
boundsMin = spheres[primID].pos - bvhvec3( spheres[primID].r );
boundsMax = spheres[primID].pos + bvhvec3( spheres[primID].r );
}
void Init()
{
// load raw vertex data for Crytek's Sponza
std::fstream s{ "./testdata/cryteksponza.bin", s.binary | s.in };
s.read( (char*)&verts, 4 );
printf( "Loading triangle data (%i tris).\n", verts );
verts *= 3, triangles = (bvhvec4*)malloc64( verts * 16 );
s.read( (char*)triangles, verts * 16 );
sponza.Build( triangles, verts / 3 );
// create a blas for a single sphere
spheres = new Sphere[1];
spheres[0].pos = bvhvec3( 0 ), spheres[0].r = 2;
obj.Build( &sphereAABB, 1 );
obj.customIntersect = &sphereIntersect;
obj.customIsOccluded = &sphereIsOccluded;
// create instance list
inst[0] = BLASInstance( 0 /* sponza */ );
inst[1] = BLASInstance( 1 /* sphere */ );
}
bool UpdateCamera( float delta_time_s, fenster& f )
{
bvhvec3 right = tinybvh_normalize( tinybvh_cross( bvhvec3( 0, 1, 0 ), view ) ), up = 0.8f * tinybvh_cross( view, right );
float moved = 0, spd = 10.0f * delta_time_s;
if (f.keys['A'] || f.keys['D']) eye += right * (f.keys['D'] ? spd : -spd), moved = 1;
if (f.keys['W'] || f.keys['S']) eye += view * (f.keys['W'] ? spd : -spd), moved = 1;
if (f.keys['R'] || f.keys['F']) eye += up * 2.0f * (f.keys['R'] ? spd : -spd), moved = 1;
if (f.keys[20]) view = tinybvh_normalize( view + right * -0.1f * spd ), moved = 1;
if (f.keys[19]) view = tinybvh_normalize( view + right * 0.1f * spd ), moved = 1;
if (f.keys[17]) view = tinybvh_normalize( view + up * -0.1f * spd ), moved = 1;
if (f.keys[18]) view = tinybvh_normalize( view + up * 0.1f * spd ), moved = 1;
// recalculate right, up
right = tinybvh_normalize( tinybvh_cross( bvhvec3( 0, 1, 0 ), view ) ), up = 0.8f * tinybvh_cross( view, right );
bvhvec3 C = eye + 1.2f * view;
p1 = C - right + up, p2 = C + right + up, p3 = C - right - up;
return moved > 0;
}
void TraceWorkerThread( uint32_t* buf, int threadIdx )
{
const int xtiles = SCRWIDTH / TILESIZE, ytiles = SCRHEIGHT / TILESIZE;
const int tiles = xtiles * ytiles;
int tile = threadIdx;
while (tile < tiles)
{
const int tx = tile % xtiles, ty = tile / xtiles;
const bvhvec3 L = tinybvh_normalize( bvhvec3( 1, 2, 3 ) );
for (int y = 0; y < TILESIZE; y++) for (int x = 0; x < TILESIZE; x++)
{
const int pixel_x = tx * TILESIZE + x, pixel_y = ty * TILESIZE + y;
const int pixelIdx = pixel_x + pixel_y * SCRWIDTH;
// setup primary ray
const float u = (float)pixel_x / SCRWIDTH, v = (float)pixel_y / SCRHEIGHT;
const bvhvec3 D = tinybvh_normalize( p1 + u * (p2 - p1) + v * (p3 - p1) - eye );
Ray ray( eye, D, 1e30f );
tlas.Intersect( ray );
if (ray.hit.t < 10000)
{
#if INST_IDX_BITS == 32
// instance and primitive index are stored in separate fields
uint32_t primIdx = ray.hit.prim;
uint32_t instIdx = ray.hit.inst;
#else
// instance and primitive index are stored together for compactness
uint32_t primIdx = ray.hit.prim & PRIM_IDX_MASK;
uint32_t instIdx = (uint32_t)ray.hit.prim >> INST_IDX_SHFT;
#endif
BLASInstance& instance = inst[instIdx];
uint32_t blasIdx = instance.blasIdx;
bvhvec3 N;
if (blasIdx == 0)
{
// we hit the Sponza mesh, which consists of triangles
bvhvec3 v0 = triangles[primIdx * 3];
bvhvec3 v1 = triangles[primIdx * 3 + 1];
bvhvec3 v2 = triangles[primIdx * 3 + 2];
N = tinybvh_normalize( tinybvh_cross( v1 - v0, v2 - v0 ) );
// the next line is disabled because we know Sponza is used with an identity transform.
// N = tinybvh_transform_vector( N, instance.transform );
}
else
{
// we hit a sphere
bvhvec3 C = tinybvh_transform_point( spheres[primIdx].pos, instance.transform );
bvhvec3 I = ray.O + ray.hit.t * ray.D;
N = tinybvh_normalize( I - C );
}
int c = (int)(255.9f * fabs( tinybvh_dot( N, L ) ));
buf[pixelIdx] = c + (c << 8) + (c << 16);
}
}
tile = tileIdx++;
}
}
void Tick( float delta_time_s, fenster& f, uint32_t* buf )
{
// handle user input and update camera
UpdateCamera( delta_time_s, f );
// clear the screen with a debug-friendly color
for (int i = 0; i < SCRWIDTH * SCRHEIGHT; i++) buf[i] = 0xaaaaff;
// position the sphere
static float bally = 20, ballv = 0;
ballv -= 0.05f;
bally += ballv;
inst[1].transform[7] = bally;
if (sponza.IntersectSphere( bvhvec3( 0, bally, 0 ), 2 )) ballv = -ballv;
// build the tlas
tlas.Build( inst, 2, bvhList, 2 );
// render tiles
tileIdx = threadCount;
std::vector<std::thread> threads;
for (uint32_t i = 0; i < threadCount; i++)
threads.emplace_back( &TraceWorkerThread, buf, i );
for (auto& thread : threads) thread.join();
}
void Shutdown() { /* nothing here. */ }