[][src]Crate nsi

Nodal Scene Interface – ɴsɪ

A flexible, modern API for offline 3D renderers

Nsɪ is built around the concept of nodes. Each node has a unique handle to identify it. It also has a type which describes its intended function in the scene.

Nodes are abstract containers for data. The interpretation depends on the node type. Nodes can also be connected to each other to express relationships.

Data is stored on nodes as attributes. Each attribute has a name which is unique on the node and a type which describes the kind of data it holds (strings, integer numbers, floating point numbers, etc).

Relationships and data flow between nodes are represented as connections. Connections have a source and a destination. Both can be either a node or a specific attribute of a node. There are no type restrictions for connections in the interface itself. It is acceptable to connect attributes of different types or even attributes to nodes. The validity of such connections depends on the types of the nodes involved.

What we refer to as the ɴsɪ has two major components:

  1. Methods to create nodes, attributes and their connections. These are attached to a rendering Context.

  2. Nodes of different NodeTypes understood by the renderer.

Much of the complexity and expressiveness of the interface comes from the supported nodes.

The first part was kept deliberately simple to make it easy to support multiple ways of creating nodes.


// Create a context to send the scene to.
let ctx = nsi::Context::new(&[]).expect("Could not create NSI context.");

// Create a dodecahedron.
let face_index: [i32; 60] =
    // 12 regular pentagon faces.
         0, 16,  2, 10,  8,  0,  8,  4, 14, 12,
        16, 17,  1, 12,  0,  1,  9, 11,  3, 17,
         1, 12, 14,  5,  9,  2, 13, 15,  6, 10,
        13,  3, 17, 16,  2,  3, 11,  7, 15, 13,
         4,  8, 10,  6, 18, 14,  5, 19, 18,  4,
         5, 19,  7, 11,  9, 15,  7, 19, 18,  6,
let positions: [f32; 60] =
    // 20 points @ 3 vertices.
         1.,     1.,     1.,     1.,     1.,    -1.,
         1.,    -1.,     1.,     1.,    -1.,    -1.,
        -1.,     1.,     1.,    -1.,     1.,    -1.,
        -1.,    -1.,     1.,    -1.,    -1.,    -1.,
         0.,     0.618,  1.618,  0.,     0.618, -1.618,
         0.,    -0.618,  1.618,  0.,    -0.618, -1.618,
         0.618,  1.618,  0.,     0.618, -1.618,  0.,
       -0.618,  1.618,  0.,    -0.618, -1.618,  0.,
         1.618,  0.,     0.618,  1.618,  0.,    -0.618,
        -1.618,  0.,     0.618, -1.618,  0.,    -0.618,

// Create a new mesh node and call it 'dodecahedron'.
ctx.create("dodecahedron", nsi::NodeType::Mesh, &[]);

// Connect the 'dodecahedron' node to the scene's root.
ctx.connect("dodecahedron", "", ".root", "objects", &[]);

// Define the geometry of the 'dodecahedron' node.
        nsi::points!("P", &positions),
        nsi::integers!("P.indices", &face_index),
        // 5 vertices per each face.
        nsi::integers!("nvertices", &[5; 12]),
        // Render this as a subdivison surface.
        nsi::string!("subdivision.scheme", "catmull-clark"),
        // Crease each of our 30 edges a bit.
        nsi::integers!("subdivision.creasevertices", &face_index),
        nsi::floats!("subdivision.creasesharpness", &[10.; 30]),

More Examples

All the examples in this crate require a (free) 3Delight installation to run.


Demonstrates using the FnStatus callback closure during rendering.


Render directly into a Jupyter notebook.

Follow these instructions to get a Rust Jupyter kernel up and running first.


This is a full output example showing color conversion and writing data out to 8bit/channel PNG and 32bit/channel (float) OpenEXR formats.


Demonstrates rendering an OpenVDB asset. Mostly through the toolbelt helpers.

Getting Pixels

The crate has support for streaming pixels from the renderer, via callbacks (i.e. closures) during and/or after rendering via the output module. This module is enabled through the feature of the same name (see below).

Cargo Features

  • output – Add support for streaming pixels from the renderer to the calling context via closures.

  • [jupyter] – Add support for rendering to Jupyter notebooks (when using a Rust Jupyter kernel).

  • toolbelt – Add convenience methods to Context.

  • nightly – Enable some unstable features (suggested if you build with a nightly toolchain)

Linking Style

The 3Delight dynamic library (lib3delight) can either be linked to during build or loaded at runtime.

By default the lib is loaded at runtime.

  • Load lib3deligh at runtime (default). This has several advantages:

    1. If you ship your application or library you can ship it without the library. It can still run and will print an informative error if the library cannot be loaded.

    2. A user can install an updated version of the renderer and stuff will ‘just work’.

  • Dynamically link against lib3delight.

    • lib3delight becomes a depdency. If it cannot't be found your lib/app will not load/start.

    • The feature is called link_lib3delight.

    • You should disable default features (they are not needed/used) in this case:

      version = "0.5.5"
      features = [ "link_lib3delight" ]
      default-features = false
  • Download lib3delight during build.

    • lib3delight is downloaded during build. Note that this may be an outdated version. This feature mainly exists for CI purposes.

    • The feature is called download_lib3delight.


pub use crate::argument::*;
pub use crate::context::Context;
pub use crate::context::NodeType;
pub use crate::toolbelt::*;



Output Driver Callbacks


Convenience Methods for Context



Create a Callback argument.


Create a Color argument.


Create a Color array argument.


Create a Double precision argument.


Create a DoubleMatrices double precision 4×4 matrix array argument.


Create a DoubleMatrix double precision 4×4 matrix argument.


Create a Double precision array argument.


Create a Float argument.


Create a Float array argument.


Create a Integer argument.


Create a Integer array argument.


Create a Matrices single precision 4×4 matrix array argument.


Create a Matrices single precision 4×4 matrix argument.


Create a Normal argument.


Create a Normal array argument.


Create a Point argument.


Create a Pointer array argument.


Create a Pointer array argument.


Create a Point array argument.


Create a Reference argument.


Create a Reference array argument.


Create a String argument.


Create a String array argument.


Create a Vector argument.


Create a Vector array argument.