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3 Commits

Author SHA1 Message Date
bf96bbf26f Some bugfixes and intersection test in Main
It seems to work, at least to some extent!
2020-12-28 17:39:58 +01:00
d36181393f Add geometry as dependency to Makefile
It compiled earlier too, but it didn't recognize changes in geometry.h
2020-12-28 17:38:10 +01:00
d966beeb15 Change Triangle to hold Vectors, not Points 2020-12-28 17:21:03 +01:00
4 changed files with 55 additions and 46 deletions

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@ -4,7 +4,7 @@ CXXFLAGS = -Wall -O3
kdtree: main.o kdtree: main.o
$(CXX) $(CXXFLAGS) -o kdtree.out main.o $(CXX) $(CXXFLAGS) -o kdtree.out main.o
main.o: main.cpp kdtree.h main.o: main.cpp kdtree.h geometry.h
$(CXX) $(CXXFLAGS) -c main.cpp $(CXX) $(CXXFLAGS) -c main.cpp
clean : clean :

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@ -1,25 +1,7 @@
#include <vector>
// Forward declarations // Forward declarations
struct Point; struct Triangle;
struct Node {
Node(int axis, Point *point, Node *left, Node *right)
: axis(axis), point(point), left(left), right(right) {}
int axis;
Point *point;
Node *left;
Node *right;
};
struct Triangle {
Triangle(Point *p1, Point *p2, Point *p3) : p1(p1), p2(p2), p3(p3) {}
Point *p1;
Point *p2;
Point *p3;
};
struct Vector { struct Vector {
Vector(float coordinates[3]) : c(coordinates) {} Vector(float coordinates[3]) : c(coordinates) {}
@ -42,24 +24,47 @@ struct Vector {
} }
Vector cross(const Vector &other) { Vector cross(const Vector &other) {
return Vector(c[2] * other[3] - c[3] - other[2], c[3] * other[1] - c[1] * other[3], return Vector(c[1] * other[2] - c[2] - other[1], c[2] * other[0] - c[0] * other[2],
c[1] * other[2] - c[2] * other[1]); c[0] * other[1] - c[1] * other[0]);
} }
float dot(const Vector &other) { return c[1] * other[1] + c[2] * other[2] + c[3] * other[3]; } float dot(const Vector &other) { return c[0] * other[0] + c[1] * other[1] + c[2] * other[2]; }
float *c; float *c;
}; };
struct Point { struct Point {
Point(float coordinates[3], Triangle *triangle) Point(Vector pos, Triangle *triangle) : pos(pos), triangle(triangle) {}
: pos(Vector(coordinates)), triangle(triangle) {}
Vector pos; Vector pos;
Triangle *triangle; Triangle *triangle;
}; };
struct Triangle {
Triangle(Vector p1, Vector p2, Vector p3) : p1(p1), p2(p2), p3(p3) {}
std::vector<Point *> create_point_objects() {
return std::vector<Point *>{new Point(p1, this), new Point(p2, this), new Point(p3, this)};
}
Vector p1;
Vector p2;
Vector p3;
};
struct Node {
Node(int axis, Point *point, Node *left, Node *right)
: axis(axis), point(point), left(left), right(right) {}
int axis;
Point *point;
Node *left;
Node *right;
};
struct Ray { struct Ray {
Ray(Vector origin, Vector direction) : origin(origin), direction(direction) {} Ray(Vector origin, Vector direction) : origin(origin), direction(direction) {}
@ -72,9 +77,9 @@ struct Ray {
// https://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore_intersection_algorithm // https://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore_intersection_algorithm
const float EPSILON = 0.0000001; const float EPSILON = 0.0000001;
Vector p1 = triangle->p1->pos; Vector p1 = triangle->p1;
Vector p2 = triangle->p2->pos; Vector p2 = triangle->p2;
Vector p3 = triangle->p3->pos; Vector p3 = triangle->p3;
Vector edge1 = p2 - p1; Vector edge1 = p2 - p1;
Vector edge2 = p3 - p1; Vector edge2 = p3 - p1;

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@ -11,7 +11,7 @@ class KDTree {
~KDTree() = default; // TODO: Delete all allocated Nodes ~KDTree() = default; // TODO: Delete all allocated Nodes
Point *intersect_ray(Ray ray) { return intersect_ray_recurse(ray, root, 1000.0); } Triangle *intersect_ray(Ray ray) { return intersect_ray_recurse(ray, root, 1000.0); }
std::string to_string() { std::string to_string() {
std::string str = ""; std::string str = "";
@ -75,7 +75,7 @@ class KDTree {
build(right_of_median, depth + 1)); build(right_of_median, depth + 1));
} }
Point *intersect_ray_recurse(Ray ray, Node *node, float max_distance) { Triangle *intersect_ray_recurse(Ray ray, Node *node, float max_distance) {
// Exit condition: There was no collision // Exit condition: There was no collision
if (node == nullptr) { return nullptr; } if (node == nullptr) { return nullptr; }
@ -85,7 +85,7 @@ class KDTree {
Node *far = near == node->right ? node->left : node->right; Node *far = near == node->right ? node->left : node->right;
std::cout << "Checking " << node->point->pos[0] << ", " << node->point->pos[1] << ", " std::cout << "Checking " << node->point->pos[0] << ", " << node->point->pos[1] << ", "
<< node->point->pos[2] << ", " << std::endl; << node->point->pos[2] << std::endl;
// Check for collisions in this order (stopping if an intersection is found): // Check for collisions in this order (stopping if an intersection is found):
// 1. In the nearer section // 1. In the nearer section
@ -98,16 +98,16 @@ class KDTree {
? (node->point->pos[node->axis] - ray.origin[node->axis]) / ? (node->point->pos[node->axis] - ray.origin[node->axis]) /
ray.direction[node->axis] ray.direction[node->axis]
: max_distance; : max_distance;
Point *near_result = intersect_ray_recurse(ray, near, t); Triangle *near_result = intersect_ray_recurse(ray, near, t);
// If the nearer segment had a collision, we're done! We're only interested in the closest // If the nearer segment had a collision, we're done! We're only interested in the closest
// collision. // collision.
if (near_result != nullptr) { return near_result; } if (near_result != nullptr) { return near_result; }
// No collision in the nearer side, so check for a collision directly here // No collision in the nearer side, so check for a collision directly here
if (node->point->triangle && ray.intersects_triangle(node->point->triangle)) { if (ray.intersects_triangle(node->point->triangle)) {
// We do have a collision here, so we're done and can return this point! // We do have a collision here, so we're done and can return this point!
return node->point; return node->point->triangle;
} }
// No collision here either. Does it make sense to also check the far node? // No collision here either. Does it make sense to also check the far node?
@ -129,7 +129,7 @@ class KDTree {
Point *point = node->point; Point *point = node->point;
str += std::string(depth, '-') + std::to_string(point->pos[0]) + ", " + str += std::string(depth * 2, ' ') + std::to_string(point->pos[0]) + ", " +
std::to_string(point->pos[1]) + ", " + std::to_string(point->pos[2]) + std::to_string(point->pos[1]) + ", " + std::to_string(point->pos[2]) +
" with axis " + std::to_string(node->axis) + "\n"; " with axis " + std::to_string(node->axis) + "\n";

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@ -2,20 +2,24 @@
#include <iostream> #include <iostream>
int main() { int main() {
std::cout << "Hello World!" << std::endl; // Testing triangles
Triangle t1 = Triangle(Vector(0.0, 0.0, 0.0), Vector(2.0, 0.0, 0.0), Vector(0.0, 2.0, 0.0));
Triangle t2 = Triangle(Vector(0.5, 0.0, 0.0), Vector(1.0, 1.0, 0.0), Vector(1.0, 1.0, 1.0));
// Test points // Create list of all points from triangles
std::vector<Point *> points{new Point(new float[3]{0.0, 0.0, 0.0}, nullptr), std::vector<Point *> points = t1.create_point_objects();
new Point(new float[3]{0.0, 1.0, 0.0}, nullptr), std::vector<Point *> other_points = t2.create_point_objects();
new Point(new float[3]{0.0, 2.0, 3.0}, nullptr), points.insert(points.end(), other_points.begin(), other_points.end());
new Point(new float[3]{1.0, 0.0, 4.0}, nullptr),
new Point(new float[3]{1.0, -1.0, 8.0}, nullptr)};
// Create and print the KDTree resulting from these points
KDTree tree = KDTree(points); KDTree tree = KDTree(points);
std::cout << tree.to_string(); std::cout << tree.to_string();
tree.intersect_ray(Ray(new float[3]{0.0, 0.0, 5.0}, new float[3]{0.0, 0.0, -1.0})); // Intersection check
Triangle *intersection =
tree.intersect_ray(Ray(new float[3]{0.5, 0.5, -1.0}, new float[3]{0.0, 0.1, 1.0}));
if (intersection != nullptr) { std::cout << "Hit!" << std::endl; }
return 0; return 0;
} }