void ambient_occlusion(vec *col, const Isect *isect)
{
int i, j;
int ntheta = AOBENCH_NAO_SAMPLES;
int nphi = AOBENCH_NAO_SAMPLES;
aobfloat eps = 0.0001;
vec p;
p.x = isect->p.x + eps * isect->n.x;
p.y = isect->p.y + eps * isect->n.y;
p.z = isect->p.z + eps * isect->n.z;
vec basis[3];
orthoBasis(basis, isect->n);
aobfloat occlusion = 0.0;
for (j = 0; j < ntheta; j++) {
for (i = 0; i < nphi; i++) {
aobfloat theta = sqrt(drand48());
aobfloat phi = 2.0 * M_PI * drand48();
aobfloat x = cos(phi) * theta;
aobfloat y = sin(phi) * theta;
aobfloat z = sqrt(1.0 - theta * theta);
// local -> global
aobfloat rx = x * basis[0].x + y * basis[1].x + z * basis[2].x;
aobfloat ry = x * basis[0].y + y * basis[1].y + z * basis[2].y;
aobfloat rz = x * basis[0].z + y * basis[1].z + z * basis[2].z;
Ray ray;
ray.org = p;
ray.dir.x = rx;
ray.dir.y = ry;
ray.dir.z = rz;
Isect occIsect;
occIsect.t = 1.0e+17;
occIsect.hit = 0;
ray_sphere_intersect(&occIsect, &ray, &spheres[0]);
ray_sphere_intersect(&occIsect, &ray, &spheres[1]);
ray_sphere_intersect(&occIsect, &ray, &spheres[2]);
ray_plane_intersect (&occIsect, &ray, &plane);
if (occIsect.hit) occlusion += 1.0;
}
}
occlusion = (ntheta * nphi - occlusion) / (aobfloat)(ntheta * nphi);
col->x = occlusion;
col->y = occlusion;
col->z = occlusion;
}
static float
ambient_occlusion(Isect &isect, Plane &plane,
Sphere spheres[3]) {
float eps = 0.0001f;
vec p, n;
vec basis[3];
float occlusion = 0.0;
p = isect.p + eps * isect.n;
orthoBasis(basis, isect.n);
static const int ntheta = NAO_SAMPLES;
static const int nphi = NAO_SAMPLES;
for (int j = 0; j < ntheta; j++) {
for (int i = 0; i < nphi; i++) {
Ray ray;
Isect occIsect;
float theta = sqrtf(drand48());
float phi = 2.0f * M_PI * drand48();
float x = cosf(phi) * theta;
float y = sinf(phi) * theta;
float z = sqrtf(1.0f - theta * theta);
// local . global
float rx = x * basis[0].x + y * basis[1].x + z * basis[2].x;
float ry = x * basis[0].y + y * basis[1].y + z * basis[2].y;
float rz = x * basis[0].z + y * basis[1].z + z * basis[2].z;
ray.org = p;
ray.dir.x = rx;
ray.dir.y = ry;
ray.dir.z = rz;
occIsect.t = 1.0e+17f;
occIsect.hit = 0;
for (int snum = 0; snum < 3; ++snum)
ray_sphere_intersect(occIsect, ray, spheres[snum]);
ray_plane_intersect (occIsect, ray, plane);
if (occIsect.hit) occlusion += 1.f;
}
}
occlusion = (ntheta * nphi - occlusion) / (float)(ntheta * nphi);
return occlusion;
}
static void ambient_occlusion(vec *col, const Isect *isect)
{
int i, j;
int ntheta = NAO_SAMPLES;
int nphi = NAO_SAMPLES;
double eps = 0.0001;
vec p;
ao_vmultsadd(&p, isect->n, eps, isect->p);
/*
p.x = isect->p.x + eps * isect->n.x;
p.y = isect->p.y + eps * isect->n.y;
p.z = isect->p.z + eps * isect->n.z;
*/
vec basis[3];
orthoBasis(basis, isect->n);
double occlusion = 0.0;
for (j = 0; j < ntheta; j++) {
for (i = 0; i < nphi; i++) {
double theta = sqrt(drand48());
double phi = 2.0 * M_PI * drand48();
double x = cos(phi) * theta;
double y = sin(phi) * theta;
double z = sqrt(1.0 - theta * theta);
// TODO
// local -> global
double rx = x * basis[0].x + y * basis[1].x + z * basis[2].x;
double ry = x * basis[0].y + y * basis[1].y + z * basis[2].y;
double rz = x * basis[0].z + y * basis[1].z + z * basis[2].z;
Ray ray;
ray.org = p;
ray.dir.x = rx;
ray.dir.y = ry;
ray.dir.z = rz;
Isect occIsect;
occIsect.t = 1.0e+17;
occIsect.hit = 0;
ray_sphere_intersect(&occIsect, &ray, &spheres[0]);
ray_sphere_intersect(&occIsect, &ray, &spheres[1]);
ray_sphere_intersect(&occIsect, &ray, &spheres[2]);
ray_plane_intersect (&occIsect, &ray, &plane);
if (occIsect.hit) occlusion += 1.0;
}
}
occlusion = (ntheta * nphi - occlusion) / (double)(ntheta * nphi);
col->x = occlusion;
col->y = occlusion;
col->z = occlusion;
}
