Implicit grids are a practical data structure for world-space, scene-wide spatial lookups. They can be built in sub-millisecond times for hundreds of thousands of objects and queried very efficiently on the GPU, making them suitable for light culling and decal rendering, especially when typical solutions like deferred & clustered shading are not available.
The pre-print of our paper is available here. This program was used for the benchmarks in the paper.
Despite being by the same group that makes Tauray, it is not based on it due to differences in goals. This is a gutted version of an unrelated codebase that may be open-sourced in full at some point later on.
Files related to implicit grid implementation:
| Name | Purpose |
|---|---|
gfx/clustering.glsl |
Lookups from the data structure |
gfx/clustering.comp |
Builds implicit grid |
gfx/clustering_hierarchy.comp |
Builds hierarchy layer |
gfx/clustering_stage.{cc,hh} |
CPU-side render pass code |
gfx/decal_ranges.comp |
Evaluates range of decal volume across axes |
gfx/light_ranges.comp |
Evaluates range of light volume across axes |
gfx/decal_order.comp |
Calculates sorting key for decals |
gfx/light_morton.comp |
Calculates sorting key for lights |
The clustering term is used only for historical reasons; binning would be
better.
The program has been tested only on Ubuntu 22.04, don't expect a Windows build to be easy.
cmake -S . -B release -DCMAKE_BUILD_TYPE=Release
cmake --build release
We don't include the Sponza scene in the repo, you'll need to download that
separately. You can get the .gltf version from here,
import it into Blender and export it as a .glb file,
which is expected by this program. Place it into data/sponza.glb.
release/ig_benchmark
The program will start up as a black window.
Initially, it's set up to benchmark ray traced light culling. By pressing 'f', you can swap between light culling and decal rendering tests. By pressing 'r', you can swap between ray tracing and multi-view tests.
You can start the currently selected benchmark with the 't' key. Timing data is printed in stdout.