Spectrum SubsurfaceOctreeNode::Mo(const BBox &nodeBound, const Point &pt,
const DiffusionReflectance &Rd, float maxError) {
// Compute $M_\roman{o}$ at node if error is low enough
float dw = sumArea / DistanceSquared(pt, p);
if (dw < maxError && !nodeBound.Inside(pt))
{
PBRT_SUBSURFACE_ADDED_INTERIOR_CONTRIBUTION(const_cast<SubsurfaceOctreeNode *>(this));
return Rd(DistanceSquared(pt, p)) * E * sumArea;
}
// Otherwise comupte $M_\roman{o}$ from points in leaf or recursively visit children
Spectrum Mo = 0.f;
if (isLeaf) {
// Accumulate $M_\roman{o}$ from leaf node
for (int i = 0; i < 8; ++i) {
if (!ips[i]) break;
PBRT_SUBSURFACE_ADDED_POINT_CONTRIBUTION(const_cast<IrradiancePoint *>(ips[i]));
Mo += Rd(DistanceSquared(pt, ips[i]->p)) * ips[i]->E * ips[i]->area;
}
}
else {
// Recursively visit children nodes to compute $M_\roman{o}$
Point pMid = .5f * nodeBound.pMin + .5f * nodeBound.pMax;
for (int child = 0; child < 8; ++child) {
if (!children[child]) continue;
BBox childBound = octreeChildBound(child, nodeBound, pMid);
Mo += children[child]->Mo(childBound, pt, Rd, maxError);
}
}
return Mo;
}
bool GridAccel::IntersectP(const Ray &ray) const {
if (!gridForRefined) { // NOBOOK
rayTests.Add(0, 1); // NOBOOK
rayHits.Add(0, 1); // NOBOOK
} // NOBOOK
int rayId = ++curMailboxId;
// Check ray against overall grid bounds
float rayT;
if (bounds.Inside(ray(ray.mint)))
rayT = ray.mint;
else if (!bounds.IntersectP(ray, &rayT))
return false;
Point gridIntersect = ray(rayT);
// Set up 3D DDA for ray
float NextCrossingT[3], DeltaT[3];
int Step[3], Out[3], Pos[3];
for (int axis = 0; axis < 3; ++axis) {
// Compute current voxel for axis
Pos[axis] = PosToVoxel(gridIntersect, axis);
if (ray.d[axis] >= 0) {
// Handle ray with positive direction for voxel stepping
NextCrossingT[axis] = rayT +
(VoxelToPos(Pos[axis]+1, axis) - gridIntersect[axis]) /
ray.d[axis];
DeltaT[axis] = Width[axis] / ray.d[axis];
Step[axis] = 1;
Out[axis] = NVoxels[axis];
}
else {
// Handle ray with negative direction for voxel stepping
NextCrossingT[axis] = rayT +
(VoxelToPos(Pos[axis], axis) - gridIntersect[axis]) /
ray.d[axis];
DeltaT[axis] = -Width[axis] / ray.d[axis];
Step[axis] = -1;
Out[axis] = -1;
}
}
// Walk grid for shadow ray
for (;;) {
int offset = Offset(Pos[0], Pos[1], Pos[2]);
Voxel *voxel = voxels[offset];
if (voxel && voxel->IntersectP(ray, rayId))
return true;
// Advance to next voxel
// Find _stepAxis_ for stepping to next voxel
int bits = ((NextCrossingT[0] < NextCrossingT[1]) << 2) +
((NextCrossingT[0] < NextCrossingT[2]) << 1) +
((NextCrossingT[1] < NextCrossingT[2]));
const int cmpToAxis[8] = { 2, 1, 2, 1, 2, 2, 0, 0 };
int stepAxis = cmpToAxis[bits];
if (ray.maxt < NextCrossingT[stepAxis])
break;
Pos[stepAxis] += Step[stepAxis];
if (Pos[stepAxis] == Out[stepAxis])
break;
NextCrossingT[stepAxis] += DeltaT[stepAxis];
}
return false;
}
TEST_F(BBoxTest, InsideDetectsPointOnBorderAsInside) {
BBox b (Point (1, 1, 1), Point (3, 3, 3));
Point p (3, 3, 3);
bool result = b.Inside (p);
EXPECT_TRUE (result);
}
TEST_F(BBoxTest, InsideDetectsPointOutside) {
BBox b (Point (1, 1, 1), Point (3, 3, 3));
Point p (4, 4, 4);
bool result = b.Inside (p);
EXPECT_FALSE (result);
}
float VolumeGrid::Density(const Point &Pobj) const {
if (!extent.Inside(Pobj)) return 0;
// Compute voxel coordinates and offsets for _Pobj_
float voxx = (Pobj.x - extent.pMin.x) /
(extent.pMax.x - extent.pMin.x) * nx - .5f;
float voxy = (Pobj.y - extent.pMin.y) /
(extent.pMax.y - extent.pMin.y) * ny - .5f;
float voxz = (Pobj.z - extent.pMin.z) /
(extent.pMax.z - extent.pMin.z) * nz - .5f;
int vx = Floor2Int(voxx);
int vy = Floor2Int(voxy);
int vz = Floor2Int(voxz);
float dx = voxx - vx, dy = voxy - vy, dz = voxz - vz;
// Trilinearly interpolate density values to compute local density
float d00 = Lerp(dx, D(vx, vy, vz), D(vx+1, vy, vz));
float d10 = Lerp(dx, D(vx, vy+1, vz), D(vx+1, vy+1, vz));
float d01 = Lerp(dx, D(vx, vy, vz+1), D(vx+1, vy, vz+1));
float d11 = Lerp(dx, D(vx, vy+1, vz+1),D(vx+1, vy+1, vz+1));
float d0 = Lerp(dy, d00, d10);
float d1 = Lerp(dy, d01, d11);
return Lerp(dz, d0, d1);
}
// get/update camera from values in node
GvBool GvViewpoint::getCamera(GCamera &camera,
BBox &bbox,
float visibilityLimitNear,float visibilityLimit,
Matrix *cameraTransform)
{
Matrix m;
float viewAngle = 0.785398;
float aspectRatio = 1.0f;
orientation.get(m);
camera.position=position;
viewAngle = (float) fieldOfView;
Point dir(0,0,-1.0);
Point up(0,1.0,0);
// apply orientation to standard dir and up vectors
dir *= m;
up *= m; up.Normalize();
if (cameraTransform) {
camera.position *= *cameraTransform;
dir = RotateOnly(*cameraTransform,dir);
up = RotateOnly(*cameraTransform,up);
// near far focalDistance ??????????
}
dir.Normalize();
up.Normalize();
Point size = bbox.Size(); // computed bounding box
float field = max(max(fabs(size.x),fabs(size.y)),fabs(size.z));
int positionInBox = bbox.Inside(camera.position);
if (bbox.IsEmpty() || (field<=1E-20f))
field = 2.0f; // no bounding box yet, bad
// compute distance to target point
//xx float targetDistance = field*2.0f;
float targetDistance = field*1.0f;
// viewpoint inside scene
if (positionInBox) targetDistance = 0.2 * field;
camera.targetDistanceIsDefault=1;
camera.zrangeIsDefault=1;
// compute a reasonable z-range
if (visibilityLimit >0.0f) {
camera.zfar = visibilityLimit;
camera.zrangeIsDefault=0;
}
else {
if (positionInBox)
camera.zfar = field*1.5;
else camera.zfar = field*3.0f;
Point center = bbox.Center();
Point d = camera.position - center;
float dist = d.Length();
// make shure object is visible from viewpoint
if ((dist+field) > camera.zfar)
camera.zfar = dist + field;
}
if (visibilityLimitNear > 0.0f)
camera.znear = visibilityLimitNear;
else
camera.znear = camera.zfar * camera.znearFactor;
// compute target
camera.target = camera.position + targetDistance*dir;
camera.up = up;
// field of view
camera.height = 2.0 * tan(viewAngle * 0.5)*targetDistance;
camera.width = camera.height * aspectRatio;
if (!bbox.IsEmpty())
camera.SetWorldReference(bbox);
camera.ComputeWorldUpFromUp();
camera.OnChanged();
return gtrue;
}
