10 releases (5 breaking)
|0.6.0||Mar 25, 2023|
|0.5.0||Mar 24, 2023|
|0.4.0||Nov 13, 2022|
|0.3.0||Aug 8, 2022|
|0.1.4||Jan 26, 2022|
#109 in Game dev
811 downloads per month
Used in big_space
High performance instanced polyline rendering for bevy
Bevy Polyline is a plugin for Bevy Engine that adds instanced rendering of
Polylines. The plugin comes courtesy of Foresight Mining Software Corporation who sponsor its creation and maintenance. Special thanks to mtsr for the initial implementation of this plugin.
Bevy Polyline closely mimics the way
Meshes are rendered in Bevy. It works internally by passing a minimal Instance Buffer to the GPU, containing only the line segment endpoints and then completely determines all vertex positions within the vertex shader, such that the triangles form a line that is rotated around it's longitudinal axis to face towards the camera. The shader code is based on this great tutorial by Rye Terrell.
minimal example for basic usage.
Polylines respect positioning through
GlobalTransform, so you can position them directly, or through the use of a
Currently the main way of customizing a
Polyline is by changing the
PolylineMaterial, which, as can be seen above, has fields for
width directly correlates to screen pixels in non-perspective mode. In
width gets divided by the w component of the homogeneous coordinate, meaning it corresponds to screen pixels at the near plane and becomes progressively smaller further away.
Bevy Polyline does some work to reduce aliasing, by implementing the line thinness fade from https://acegikmo.com/shapes/docs/#anti-aliasing. But if your line segments are very short, you will still see shimmering, caused by triangles < 1 pixel in size. This can be reduced by only adding segments of a minimum length.
Due to instancing, Bevy Polyline only makes one drawcall per
PolyLine, one for the line segments
and one for the miter joins (not currently enabled). We've tested the
nbody demo at some 500 lines with 4096 segments being updated every frame (in addition to a 4th order Yoshida integrator for the nbody simulation) running at 60fps. There is still some room for performance optimization, particularly reducing to one drawcall per
Polyline (depending on join and cap types) and more efficient updates of the instance buffer for updated lines.
Bevy Version Support
We intend to track the
main branch of Bevy. PRs supporting this are welcome!
If you want some help using this plugin, you can ask in the Bevy Discord at https://discord.gg/bevy.
bevy_polyline is free and open source! All code in this repository is dual-licensed under either:
- MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
at your option. This means you can select the license you prefer! This dual-licensing approach is the de-facto standard in the Rust ecosystem and there are very good reasons to include both.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
The creation and maintenance of Bevy Polyline is sponsored by Foresight Mining Software Corporation.