2017年4月22日 · R-tree is a class of BVH data structures that uses rectangles as bounding-volume. Rectangles are easy to store and they can cover other shapes easily. It is noted that R-tree is not the only class of BVH and there are other BVHs proposed using different shapes. Even among R-trees, there is a variety.

Here is a picture explaining BVH. In contrast, Octrees/K-d trees and other space subdivision, divide the space recursively. A simple picture of an octree given in the paper.

2020年8月10日 · Regarding fast BVH reconstruction, it may be interesting to take a look at the LBVH, by Lauterbach et. al., the HLBVH, by Pantaleoni and Luebke, and the one by Karras and Aila, that are capable to rebuild BVHs iteractively. Overlapping impacts the traversal procedure efficiency because, when a ray hit the overlap, it has to be tested against ...

Stepping through the random_scene() case of the code, found out that once a leaf of the BVH tree is reached, the aabb of the object is checked for a hit; even when the object is a sphere. The check for a hit against the bounding_box of a sphere (aabb) is necessary but not sufficient; there are parts of the bounding_box which is not a part of a ...

2016年3月4日 · There is a datastructure called Bounding Volume Hierachy (BVH) which groups triangles and fits a bounding volume (e.g. AABBs - axis-aligned bounding boxes) around it. The idea is that if the ray does not intersect the bounding volume, it does not intersect any of the contained triangles / other bounding volumes.

2023年9月21日 · For example, given a node X in a BSP tree, all nodes in X's left subtree are in front of X, and all nodes in X's right subtree are behind X. On the other hand, a BVH is like an AABB tree whose nodes represent the hierarchical bounding boxes of objects. Unlike BSP, a BVH needs an explicit visibility culling algorithm.

2020年5月13日 · I'm trying to implement a BVH for my ray tracer and I looked at some lectures explaining BVH. They all mention that a BVH takes in primitives which are then divided until they end up as nodes of the tree, but when I looked at scratch-pixel, they were talking about having the meshes as nodes.

2021年6月30日 · situation: I've implemented a Whitted style ray tracing in C. Everything appear to works except the shadow cast by small object on big far objects The problem : red sphere have radius 0.5 orange sp...

A fast and simple BVH construction approach (the one I'm using currently) is to sort all objects on an axis (for example the parent AABB's longest axis) and split the collection in the middle. To speed things up even more, calculate the node AABBs AFTER constructing the tree, by combining the two child node AABBs of a parent node.

2020年9月4日 · I am using the SAH-BVH from PBRT-v3, it works fine for triangle-mesh, especially for dense mesh. But here is a problem. If I added Cornell box while building the BVH tree, the BVH performance will drop to only 20% as before. The Cornell box is only 6 rectangles. Why does it behave in this way? Because it's a big box containing everything?