Expand description
A crate which exports rays, axis-aligned bounding boxes, and binary bounding volume hierarchies.
About
This crate can be used for applications which contain intersection computations of rays
with primitives. For this purpose a binary tree BVH (Bounding Volume Hierarchy) is of great
use if the scene which the ray traverses contains a huge number of primitives. With a BVH the
intersection test complexity is reduced from O(n) to O(log2(n)) at the cost of building
the BVH once in advance. This technique is especially useful in ray/path tracers. For
use in a shader this module also exports a flattening procedure, which allows for
iterative traversal of the BVH.
This library is built on top of nalgebra
.
Example
use bvh::aabb::{AABB, Bounded};
use bvh::bounding_hierarchy::{BoundingHierarchy, BHShape};
use bvh::bvh::BVH;
use bvh::nalgebra::{Point3, Vector3};
use bvh::ray::Ray;
let origin = Point3::new(0.0,0.0,0.0);
let direction = Vector3::new(1.0,0.0,0.0);
let ray = Ray::new(origin, direction);
struct Sphere {
position: Point3<f32>,
radius: f32,
node_index: usize,
}
impl Bounded for Sphere {
fn aabb(&self) -> AABB {
let half_size = Vector3::new(self.radius, self.radius, self.radius);
let min = self.position - half_size;
let max = self.position + half_size;
AABB::with_bounds(min, max)
}
}
impl BHShape for Sphere {
fn set_bh_node_index(&mut self, index: usize) {
self.node_index = index;
}
fn bh_node_index(&self) -> usize {
self.node_index
}
}
let mut spheres = Vec::new();
for i in 0..1000u32 {
let position = Point3::new(i as f32, i as f32, i as f32);
let radius = (i % 10) as f32 + 1.0;
spheres.push(Sphere {
position: position,
radius: radius,
node_index: 0,
});
}
let bvh = BVH::build(&mut spheres);
let hit_sphere_aabbs = bvh.traverse(&ray, &spheres);
Re-exports
pub extern crate nalgebra;
Modules
Axis Aligned Bounding Boxes.
Axis enum for indexing three-dimensional structures.
This module defines the
BoundingHierarchy
trait.This module exports methods to flatten the
BVH
and traverse it iteratively.This module defines a Ray structure and intersection algorithms
for axis aligned bounding boxes and triangles.
Constants
A minimal floating value used as a lower bound.
TODO: replace by/add ULPS/relative float comparison methods.