Bevy Clipmap

Overview

This project implements GPU-Based Geometry Clipmaps from this paper: https://hhoppe.com/gpugcm.pdf

This is an adaptive LOD technique that allows us to render huge worlds for cheap!

Usage

The example usage can be seen in the examples directory. This example uses very low-resolution maps to save space when cloning this repository. Especially horizon maps can become quite huge. For better visual results, create your own higher-resolution textures.

How to create textures

To create heightmap and horizon map textures you can use the clipmap.py script.

First of all, you have to install required libraries:

> pip install -r requirements.txt

> python clipmap.py --help

usage: clipmap.py [-h] filename {ktx,horizon} ...


Heightmap processing tool for the bevy-clipmap plugin


positional arguments:

  filename       16-bit PNG heightmap

  {ktx,horizon}
    ktx          Convert the heightmap to KTX2

    horizon      Create KTX2 horizon map


options:

  -h, --help     show this help message and exit

Example usage:

> python clipmap.py heightmap.png ktx 8192 8192 # Convert 16-bit PNG to 8192x8192 KTX

> python clipmap.py heightmap.png horizon 2048 2048 16 # Convert 16-bit PNG to 2048x2048 horizon map with 16 FFT coefficients

Warning: Horizon maps require significant disk space. It generates 360 horizon maps and requires 360 * W * H * 4 bytes. For 1k map it requires only 1.4GB, but for 16k map it leads to 360GB.

Compatible Bevy versions

Contributing

PRs are very welcome!