- Bounding Volume Hierarchy (BVH) is a popular ray tracing acceleration technique that uses a tree-based “acceleration structure” that contains multiple hierarchically-arranged bounding boxes (bounding volumes) that encompass or surround different amounts of scene geometry or primitives. Testing each ray against every primitive intersection in the scene is inefficient and computationally expensive, and BVH is one of many techniques and optimizations that can be used to accelerate it. The BVH can be organized in different types of tree structures and each ray only needs to be tested against the BVH using a depth-first tree traversal process instead of against every primitive in the scene. Prior to rendering a scene for the first time, a BVH structure must be created (called BVH building) from source geometry. The next frame will require either a new BVH build operation or a BVH refitting based on scene changes.
Why would Alex need to explain it is a data structure? Almost everything in a pipeline is a data structure, I don't see the point. The tree structure in the end is replicating a form of simplified scene geometry / primitives. It is testing if a ray will hit a geometry. The bounding box is literally
based on geometry, not thin air. Once it hits a box and it is a leaf node (if not then it will test the children), it will test the triangles in that node for a hit.
Alex says so here too in his simplified version of it @ 4:10.
"so a ray shot into a scene goes through these layers of boxes until it finally hits and enters one and registers a hit against geometry so the more rays that are shot out here the further that ray travels or the more boxes that that ray touches the more milliseconds this step will need"
It's the same fucking thing in the end unless you want to police jargon and even between university and paper literature on ray tracing it varies.
Seems more like an
I don't get the hate.
