This is an artist-friendly user interface that wraps the glTF IBL Sampler to generate cubemap skyboxes from panoramas. It provides an easy way to generate skyboxes for use in Bevy and other new game engines that use the modern KTX2 format as their native texture format. By default, the panorama is split up into base color, diffuse, and specular parts, with the mipmap levels corresponding to different roughness values of the material.
For the most part, using this tool is as easy as starting the app, dragging a
panorama in .exr or .hdr format with an equirectangular projection into the
window, and clicking Generate.
This tool's user interface is built on egui.
All options are automatically set to reasonable default values, but they can be fully customized as you wish. To get a detailed description of any option, simply hover over it with the mouse.
In general, this program simply wraps the upstream glTF IBL Sampler, with two notable feature additions for the sake of convenience:
-
OpenEXR
.exrfiles are supported in addition to the Radiance.hdrformat. -
The tool can generate unfiltered base-color skyboxes for rendering in addition to diffuse and specular environment maps. This means that you can use this tool as an all-in-one skybox generator for engines like Bevy.
This repository contains submodules, so make sure to either clone it
with git clone --recursive or use
git submodule init && git submodule sync && git submodule update
after checking it out.
As the glTF IBL Sampler is a C++ app instead of a pure Rust one, you'll need a C++ compiler such as Xcode or Visual Studio to be installed in order to build this package. Note that the Vulkan SDK and CMake are no longer required.
Note that the skybox sampling process is itself hardware-accelerated using Vulkan. So you'll need a Vulkan-capable GPU to usefully run this application. This unfortunately also means that the baking process is subject to hardware memory limitations, so baking an entire 8K × 4K panoramic texture may not work. To avoid spurious failures stemming from this limitation, textures are resized to at most 4K pixels on each side by default.
You should be able to run the app using cargo run --release.
The panorama can be stored either in any format that the Rust image crate
supports, which notably includes .exr, or in .hdr format. The resulting
textures can be stored in KTX2 format, while the BRDF lookup tables are stored in PNG format.
Licensed under the MIT license or the Apache 2.0 license, at your option. See
the LICENSE-APACHE or LICENSE-MIT files for details.
The glTF IBL Sampler UI follows the same Code of Conduct as Rust itself. Reports can be made to the project authors.