Skip to content

bvh_node: no more const qualifier of objects array, axis sorting "in place" #1409

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Mar 4, 2024
Merged

bvh_node: no more const qualifier of objects array, axis sorting "in place" #1409

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
83f0c41
-removed const qualifier for "objects" vector in bvh constructor argu…
relief7 Feb 26, 2024
41c1795
-added credits
relief7 Feb 26, 2024
78d24c1
-removed passing by ref in bvh constructor so we make a copy of the i…
relief7 Mar 1, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions CHANGELOG.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,8 @@ then.
- Change - Reworked the AABB chapter (#1236)
- New - add section on alternative 2D primitives such as triangle, ellipse and annulus (#1204,
#1205)
- Change - changed bvh construction (removed const qualifer for objects vector) so sorting is done
in place and copying of vector is avoided, better bvh build performance (#1388, #1391)

### The Rest of Your Life

Expand Down
29 changes: 11 additions & 18 deletions books/RayTracingTheNextWeek.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -899,9 +899,9 @@

class bvh_node : public hittable {
public:
bvh_node(const hittable_list& list) : bvh_node(list.objects, 0, list.objects.size()) {}
bvh_node(hittable_list list) : bvh_node(list.objects, 0, list.objects.size()) {}

bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
// To be implemented later.
}

Expand Down Expand Up @@ -956,27 +956,20 @@
class bvh_node : public hittable {
public:
...
bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
int axis = random_int(0,2);

auto comparator = (axis == 0) ? box_x_compare
: (axis == 1) ? box_y_compare
: box_z_compare;

auto objects = src_objects; // A modifiable array of the source scene objects

size_t object_span = end - start;

if (object_span == 1) {
left = right = objects[start];
} else if (object_span == 2) {
if (comparator(objects[start], objects[start+1])) {
left = objects[start];
right = objects[start+1];
} else {
left = objects[start+1];
right = objects[start];
}
left = objects[start];
right = objects[start+1];
} else {
std::sort(objects.begin() + start, objects.begin() + end, comparator);

Expand Down Expand Up @@ -1094,12 +1087,12 @@
class bvh_node : public hittable {
public:
...
bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++ highlight
// Build the bounding box of the span of source objects.
bbox = aabb::empty;
for (int object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, src_objects[object_index]->bounding_box());
for (size_t object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, objects[object_index]->bounding_box());
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++

...
Expand All @@ -1115,11 +1108,11 @@
class bvh_node : public hittable {
public:
...
bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
// Build the bounding box of the span of source objects.
bbox = aabb::empty;
for (int object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, src_objects[object_index]->bounding_box());
for (size_t object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, objects[object_index]->bounding_box());


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C++ highlight
Expand Down
1 change: 1 addition & 0 deletions books/acknowledgments.md.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,7 @@
- [Manas Kale](https://github.com/manas96)
- Marcus Ottosson
- [Mark Craig](https://github.com/mrmcsoftware)
- Markus Boos
- Matthew Heimlich
- Nakata Daisuke
- [Nate Rupsis](https://github.com/rupsis)
Expand Down
17 changes: 5 additions & 12 deletions src/TheNextWeek/bvh.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,34 +22,27 @@

class bvh_node : public hittable {
public:
bvh_node(const hittable_list& list) : bvh_node(list.objects, 0, list.objects.size()) {}
bvh_node(hittable_list list) : bvh_node(list.objects, 0, list.objects.size()) {}

bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
// Build the bounding box of the span of source objects.
bbox = aabb::empty;
for (size_t object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, src_objects[object_index]->bounding_box());
bbox = aabb(bbox, objects[object_index]->bounding_box());

int axis = bbox.longest_axis();

auto comparator = (axis == 0) ? box_x_compare
: (axis == 1) ? box_y_compare
: box_z_compare;

auto objects = src_objects; // A modifiable array of the source scene objects

size_t object_span = end - start;

if (object_span == 1) {
left = right = objects[start];
} else if (object_span == 2) {
if (comparator(objects[start], objects[start+1])) {
left = objects[start];
right = objects[start+1];
} else {
left = objects[start+1];
right = objects[start];
}
left = objects[start];
right = objects[start+1];
} else {
std::sort(objects.begin() + start, objects.begin() + end, comparator);

Expand Down
19 changes: 6 additions & 13 deletions src/TheRestOfYourLife/bvh.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,34 +22,27 @@

class bvh_node : public hittable {
public:
bvh_node(const hittable_list& list) : bvh_node(list.objects, 0, list.objects.size()) {}
bvh_node(hittable_list list) : bvh_node(list.objects, 0, list.objects.size()) {}

bvh_node(const std::vector<shared_ptr<hittable>>& src_objects, size_t start, size_t end) {
bvh_node(std::vector<shared_ptr<hittable>>& objects, size_t start, size_t end) {
// Build the bounding box of the span of source objects.
bbox = aabb::empty;
for (int object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, src_objects[object_index]->bounding_box());
for (size_t object_index=start; object_index < end; object_index++)
bbox = aabb(bbox, objects[object_index]->bounding_box());

int axis = bbox.longest_axis();

auto comparator = (axis == 0) ? box_x_compare
: (axis == 1) ? box_y_compare
: box_z_compare;

auto objects = src_objects; // A modifiable array of the source scene objects

size_t object_span = end - start;

if (object_span == 1) {
left = right = objects[start];
} else if (object_span == 2) {
if (comparator(objects[start], objects[start+1])) {
left = objects[start];
right = objects[start+1];
} else {
left = objects[start+1];
right = objects[start];
}
left = objects[start];
right = objects[start+1];
} else {
std::sort(objects.begin() + start, objects.begin() + end, comparator);

Expand Down