building-blocks

Building Blocks is a voxel library for real-time applications.

The primary focus is core data structures and algorithms. Features include:

• memory-efficient storage of voxel maps
  • a ChunkMap with generic chunk storage
  • LRU-cached storage of compressed chunks
  • compressed serialization format
  • OctreeSet bitset structure
• mesh generation
  • isosurface
  • cubic / blocky
  • height map
• accelerated spatial queries
  • ray casting and sphere casting
  • range queries
• procedural generation
  • sampling signed distance fields
  • constructive solid geometry
• pathfinding on voxel maps

Short Code Example

The code below samples a signed distance field and generates a mesh from it.

```rust use buildingblocks::{ core::sdfu::{Sphere, SDF}, prelude::*, mesh::{SurfaceNetsBuffer, surfacenets}, };

let center = PointN([25.0; 3]); let radius = 10.0; let sphere_sdf = Sphere::new(radius).translate(center);

let extent = Extent3i::fromminandshape(PointN([0; 3]), PointN([50; 3])); let mut samples = Array3::fillwith(extent, |p| sphere_sdf.dist(Point3f::from(p)));

let mut meshbuffer = SurfaceNetsBuffer::default(); let voxelsize = 2.0; // length of the edge of a voxel surfacenets(&samples, samples.extent(), voxelsize, &mut mesh_buffer); ```

Learning

Docs and Examples

The current best way to learn about the library is to read the documentation and examples. For the latest stable docs, look here. For the latest unstable docs, clone the repo and run

sh cargo doc --open

There is plentiful documentation with examples. Take a look in the examples/ directory to see how Building Blocks can be used in real applications.

Getting Started

This library is organized into several crates. The most fundamental are:

• core: lattice point and extent data types
• storage: storage for lattice maps, i.e. functions defined on Z^2 and Z^3

Then you get extra bits of functionality from the others:

• mesh: 3D mesh generation algorithms
• search: search algorithms on lattice maps

To learn the basics about lattice maps, start with these doc pages:

• points
• extents
• arrays
• access traits
• chunk maps
• transform maps
• fn maps

Benchmarks

To run the benchmarks (using the "criterion" crate), go to the root of a crate and run cargo bench.

Configuration

LTO

It is highly recommended that you enable link-time optimization when using building-blocks. It will improve the performance of critical algorithms like meshing by up to 2x. Just add this to your Cargo.toml:

toml [profile.release] lto = true

Cargo Features

Building Blocks is organized into several crates, some of which are hidden behind features, and some have features themselves, which get re-exported by the top-level crate.

Math Type Conversions

The PointN types have conversions to/from glam, nalgebra, and mint types by enabling the corresponding feature.

Compression Backends and WASM

Chunk compression supports two backends out of the box: Lz4 and Snappy. They are enabled with the "lz4" and "snappy" features. "lz4" is the default, but it relies on a C++ library, so it's not compatible with WASM. But Snappy is pure Rust, so it can! Just use default-features = false and add "snappy" to you features list, like so:

toml [dependencies.building-blocks] version = "0.4.1" default-features = false features = ["snappy"]

VOX Files

".VOX" files are supported via the dot_vox crate. Enable the dot_vox feature to expose the generic encode_vox function and Array3::decode_vox constructor.

Images

Arrays can be converted to ImageBuffers and constructed from GenericImageViews from the image crate. Enable the image feature to expose the generic encode_image function and From<Im> where Im: GenericImageView impl.

Signed Distance Field Utilities (sdfu)

The sdfu crate provides convenient APIs for constructive solid geometry operations. By enabling this feature, the PointN types will implement the sdfu::mathtypes traits in order to be used with these APIs. The sdfu crate also gets exported under building_blocks::core::sdfu.

Development

We prioritize work according to the project board.

If you'd like to make a contribution, please first read the design philosophy and contribution guidelines.

License: MIT