Se3

This repository is based on https://github.com/duckdb/extension-template, check it out if you want to build and ship your own DuckDB extension.

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This extension, Se3, provides SE(3) rigid transformations using unit quaternions, implemented as vectorized DuckDB scalar functions.

• Sequences of transformations can be combined to a 6 DOF transform stored as a 7-scalar struct: 3 translation components plus a 4-component unit quaternion.
• Combined transformations can be efficiently applied to points in 3D without calling trigonometric functions.

Building

Build (recommended):

GEN=ninja make

The main binaries that will be built are:

./build/release/duckdb
./build/release/test/unittest
./build/release/extension/se3/se3.duckdb_extension

• duckdb is the binary for the duckdb shell with the extension code automatically loaded.
• unittest is the test runner of duckdb. Again, the extension is already linked into the binary.
• se3.duckdb_extension is the loadable binary as it would be distributed.

Running the extension

To run the extension code, simply start the shell with ./build/release/duckdb.

Now we can use the features from the extension directly in DuckDB. Example (translate, then rotate):

SELECT se3_apply(
  se3_from_axis_angle(
    struct_pack(x:=1.0, y:=0.0, z:=0.0), -- translation
    struct_pack(x:=0.0, y:=0.0, z:=1.0), -- rotation axis (Z)
    pi()/2.0                             -- 90 degrees
  ),
  struct_pack(x:=1.0, y:=0.0, z:=0.0)    -- point
);

Expected result (first translate the point by (1,0,0) to (2,0,0), then rotate 90° around Z):

{x: 0.0, y: 2.0, z: 0.0}

Compose transformations with se3_compose(W2, W1): apply W1 first, then W2.

SELECT se3_apply(
  se3_compose(
    se3_from_axis_angle(struct_pack(x:=0.0, y:=1.0, z:=0.0), struct_pack(x:=0.0, y:=0.0, z:=1.0), pi()/2.0), -- W2
    se3_from_axis_angle(struct_pack(x:=1.0, y:=0.0, z:=0.0), struct_pack(x:=0.0, y:=0.0, z:=1.0), pi()/2.0)  -- W1
  ),
  struct_pack(x:=1.0, y:=0.0, z:=0.0)
);

Expected result (roundoff omitted):

{x: -3.0, y: 0.0, z: 0.0}

For the full API and semantics, see API.md and SPEC.md.

Running the tests

make test

Installing the deployed binaries

To install your extension binaries from S3, you will need to do two things. Firstly, DuckDB should be launched with the allow_unsigned_extensions option set to true. How to set this will depend on the client you're using. Some examples:

CLI:

duckdb -unsigned

Python:

con = duckdb.connect(':memory:', config={'allow_unsigned_extensions' : 'true'})

NodeJS:

db = new duckdb.Database(':memory:', {"allow_unsigned_extensions": "true"});

Secondly, you will need to set the repository endpoint in DuckDB to the HTTP url of your bucket + version of the extension you want to install. To do this run the following SQL query in DuckDB:

SET custom_extension_repository='bucket.s3.eu-west-1.amazonaws.com/<your_extension_name>/latest';

Note that the /latest path will allow you to install the latest extension version available for your current version of DuckDB. To specify a specific version, you can pass the version instead.

After running these steps, you can install and load your extension using the regular INSTALL/LOAD commands in DuckDB:

INSTALL se3;
LOAD se3;