Crate alice_sdf 

ALICE-SDF

Signed distance functions for Rust. A shape is a tree of primitives, CSG operations, transforms and modifiers (SdfNode). The crate evaluates the tree on the CPU (scalar, SIMD, BVH and JIT evaluators), transpiles it to GLSL, WGSL, HLSL and Metal, and turns it into meshes and file formats.

The CPU evaluators return bit-identical distances for the same tree and point on every platform CI tests: every transcendental goes through alice-det-math and a * b + c is never fused. The GPU shaders agree with the CPU within a tolerance.

Example

use alice_sdf::prelude::*;

// A unit sphere minus a box (box3d takes full extents)
let shape = SdfNode::sphere(1.0).subtract(SdfNode::box3d(1.0, 1.0, 1.0));

// Signed distance: negative inside, zero on the surface, positive outside
let p = Vec3::new(0.9, 0.0, 0.0);
let d = eval(&shape, p);
assert!(d < 0.0);

// Compiled to bytecode for repeated evaluation, with the same bits
let compiled = CompiledSdf::compile(&shape);
assert_eq!(eval_compiled(&compiled, p).to_bits(), d.to_bits());

// A triangle mesh by marching cubes
let mesh = sdf_to_mesh(
    &shape,
    Vec3::splat(-1.5),
    Vec3::splat(1.5),
    &MarchingCubesConfig::default(),
);
assert!(!mesh.indices.is_empty());

Cargo features

The physics, codec and sdf-cache features link crates licensed AGPL-3.0-or-later; the default features and all others do not.

Feature	Default	Description
cli	yes	The alice-sdf command-line tool (clap).
image		PNG / JPEG decoding for heightmaps and texture fitting.
texture-fit		Fit a bitmap texture with procedural noise formulas. Implies image and cli.
jit		Native evaluation through Cranelift (scalar and 8-wide).
gpu		GPU evaluation and WGSL output through wgpu.
gpu-mesh		Marching cubes on the GPU. Implies gpu.
volume		Bake a field into a 3D texture. Implies gpu.
glsl		GLSL output (Unity, OpenGL, Vulkan, Shadertoy).
hlsl		HLSL output (Unreal Engine, DirectX).
msl		Metal Shading Language output, converted from WGSL with naga. Implies gpu.
blinkscript		BlinkScript output for Nuke. Implies hlsl.
rust		Dependency-free Rust source (fn sdf, fn normal) bit-identical to eval_compiled, for build.rs.
all-shaders		gpu, glsl, hlsl, msl and blinkscript.
svo		Sparse voxel octree.
svo-gpu		Sparse voxel octree with GPU support. Implies svo and gpu.
destruction		Voxel destruction.
terrain		Heightmap terrain with erosion and caves.
gi		Cone-traced global illumination. Implies svo.
aaa		volume, gpu-mesh, svo-gpu, destruction, terrain and gi.
ffi		C ABI for C, C++, C#, Unity and Unreal Engine.
unity		ffi and glsl.
unreal		ffi, hlsl, glsl and gpu: what the Unreal Engine plugin calls.
python		Python bindings (PyO3 + NumPy).
godot		Godot 4 GDExtension.
wasm		WebAssembly bindings through wasm-bindgen (built for wasm32 only).
openvdb		OpenVDB float grid input and output.
physics		AGPL. SDF colliders and simulation modifiers for alice-physics.
codec		AGPL. Volume compression with alice-codec.
sdf-cache		AGPL. Evaluation cache with alice-cache.
asp		ALICE Streaming Protocol packets with libasp (its default features only).
font		Glyph outlines from alice-font. Inert on crates.io: also needs --cfg alice_font_bridge and a local alice-font.

Module overview: https://github.com/ext-sakamoro/ALICE-SDF/blob/main/docs/MODULES.md

Re-exports

pub use cache::compute_cache_key;

pub use cache::hash_sdf_node;

pub use cache::CacheConfig;

pub use cache::ChunkCoord;

pub use cache::ChunkedCacheConfig;

pub use cache::ChunkedMeshCache;

pub use cache::MeshCache;

pub use cache::MeshCacheKey;

pub use eval::eval;

pub use io::load;

pub use io::save;

pub use mesh::sdf_to_mesh;

pub use mesh::sdf_to_mesh;

pub use types::SdfNode;

pub use types::SdfTree;

Modules

animation

Animation System for SDF parameter morphing

autodiff

Forward-mode Automatic Differentiation via Dual Numbers

cache

SDF hash-based mesh cache with LRU eviction

collision

SDF-to-SDF collision detection.

compiled

Compiled SDF: Cache-efficient linearized evaluation

constraint

Parametric SDF constraint solver

destruction

Voxel Destruction System (Deep Fried Edition)

diff

CSG Tree structural diff and patch

eval

SDF Evaluation (Deep Fried Edition)

ffi

Foreign Function Interface (FFI) for ALICE-SDF (Deep Fried Edition)

fidelity

What a field’s distance claim is worth.

gi

Cone Tracing Global Illumination (Deep Fried Edition)

heatmap

Distance field cross-section heatmap visualization

incremental

Incremental parameter update support for CompiledSdf.

interval

Interval Arithmetic for SDF evaluation

io

File I/O for SDF trees (Deep Fried Edition)

llm_schema

LLM integration utilities for ALICE-SDF

material

PBR Material System for AAA rendering

measure

Volume, surface area, and center-of-mass estimation

mesh

Mesh conversion for SDFs (Deep Fried Edition v2)

modifiers

Modifier operations for SDFs (Deep Fried Edition)

morphology

Morphological operations on signed distance fields.

neural

Neural SDF — small MLP that approximates a Signed Distance Field.

npr

NPR (Non-Photorealistic Rendering) primitives

operations

CSG (Constructive Solid Geometry) Operations (Deep Fried Edition)

optimize

CSG tree optimization pass

prelude

Prelude - commonly used types and functions

primitives

Primitive SDF shapes (Deep Fried Edition)

raycast

Raymarching for SDFs (Deep Fried v2 Edition)

sdf2d

Pure 2D SDF evaluation module

shell

Variable-thickness offset surface (shell) modifier

soa

SoA (Structure of Arrays) Memory Layout for SIMD-Optimized Evaluation

svo

Sparse Voxel Octree (Deep Fried Edition)

terrain

Terrain System (Deep Fried Edition)

tight_aabb

Auto tight AABB computation for SDF trees

transforms

Transform operations for SDFs

types

Core types for ALICE-SDF

validity

Printability validation — ValidityReport.

Constants

SEMANTICS_ID

The numeric semantics the CPU evaluators compute distances with

VERSION

Library version