thi.ng/geom

Contents

• About the project
  • Status
  • Leiningen coordinates
    • Latest snapshot
    • Latest stable
    • Additional dependencies for JOGL
  • Overview
    • Example usage
    • Project structure
    • Main features (non-exhaustive list)
    • API scope
  • Project structure
    • core
    • types
    • utils
    • mesh
    • physics
    • svg
    • viz
    • voxel
    • OpenGL & WebGL
  • Release history & changelog
  • Contributors
  • License

About the project

Status

The project was in active, almost daily development from late 2011 - summer 2016 during its 4th iteration/rewrite cycle. Originally developed in a Literate Programming style using Emacs & Org-mode, in May 2018 it was decided to revert to a traditional Clojure project setup to encourage more contributions from other interested parties. The original .org source files are kept for reference in the ./org/ directory until further notice.

Regardless of version number, the library is mature and has been used successfully in several commercial projects over the past 10 years and can be considered stable for most use cases.

Leiningen coordinates

[thi.ng/geom "1.0.0"]

Additional dependencies for JOGL

If you’re intending to use this library’s OpenGL functionality under Clojure (not ClojureScript), the following additional native dependencies must be added to your project (for each platform you intend to use):

[org.jogamp.gluegen/gluegen-rt "2.3.2" :classifier "natives-macosx-universal"]
[org.jogamp.jogl/jogl-all "2.3.2" :classifier "natives-macosx-universal"]

The full list of supported platform :classifier’s:

Overview

thi.ng/geom is a comprehensive and modular geometry & visualization toolkit for Clojure/ClojureScript. It provides a large set of purely math & geometry oriented data types, a polymorphic, largely protocol based API to transform/convert types and various ways to create interactive visualizations in SVG, WebGL, OpenGL, both in the browser and in desktop environments.

Embracing Clojure’s approach of data transformations, the library’s core philosophy is based on a functional approach to generative design tasks with hundreds of hours spent on refining & optimizing the core API for both Clojure & Clojurescript.

Unlike most other open source projects, this project has been developed in a literate programming style and has been in active, regular development since late 2011, currently in its 4th iteration/rewrite cycle.

You’re highly encouraged to consult the source code, which contains documentation, examples, diagrams and general usage pattern hints.

This project is part of the thi.ng collection of Clojure & Clojurescript libraries and makes uses of several other projects in this collection (see dependencies further below).

Example usage

A growing number (currently ~40) of small examples are included in this repo under the /examples directory:

• OpenGL demos (Clojure)
• WebGL demos (Clojurescript + links to live versions)
• SVG examples (incl. 3D rendered meshes in SVG)
• Visualization examples (charts, heatmaps, timelines etc.)
• PTF mesh examples (mesh skinning & Luxrender)
• Voxel examples (isosurface extraction from volumetric data)

Interactive examples:

• Procedural Color Gradient designer
• SVG physics strands
• WebGL workshop teaser
• WebGL workshop example (early game prototype)

Growing list of thi.ng workshop repositories (These workshops were running on a monthly basis & internationally in 2015/2016):

• WS-LDN-1
• WS-LDN-2
• WS-BLN-1
• WS-LDN-5 (WebGL, source code forthcoming)
• WS-LDN-6 (Desktop apps, OpenGL/WebGL, source code forthcoming)
• WS-LDN-8 (WebGL, WebRTC, Web workers, asm.js)

A preliminary list of other projects using this library:

• HOLO Magazine cover & guest design
• Google DevArt Co(de)Factory
• Geometer (by Jack Rusher)
• MB Home installation
• Resonate 2015 workshop
• Resonate 2014 workshop
• thi.ng/luxor
• thi.ng/morphogen
• thi.ng website

Project structure

Use the diagram below to quickly navigate to any namespace in the project. Nodes in the graph have tooltips with a brief description of each namespace. Note: Due to GH restrictions on SVG files, first click anywhere on the diagram before trying to navigate to a specific namespace.

Main features (non-exhaustive list)

• Comprehensive & optimized 2D/3D vector & matrix algebra / transformations
• Custom, optimized vector types w/ GLSL style vector swizzling & full Clojure sequence API support
• Unified, easy-to-learn & extensible core API defined via ~50 polymorphic protocols
• Unified OpenGL (v3.3+) & WebGL abstractions of common features, shader, buffer & texture utilities
• Declarative GLSL shader specs and code generation
• Optional OpenGL/WebGL shader presets based on thi.ng/shadergraph
• Declarative OpenGL/WebGL FBO-based multi-pass shader pipeline creation & execution tools
• OpenGL helpers for desktop apps (wrapping JOGL)
• React.js component helpers for WebGL
• 3D SVG mesh renderer with software facet shader support
• SVG generation API & optional conversion of geom types
• Declararitve 2D data visualization module with various modes (area, bar, line, scatter, contours, stacks etc., cartesian/polar axes)
• 35+ custom (mainly immutable) geometry types implementing core protocols
• Shape analysis (surface area, circumference, distance & volume calculations) for all implemented types
• 2D/3D intersection & classification checks (vs. point, line, ray, shapes)
• Access entities as graph-like structures (vertices/edges)
• 2D/3D platonic entity to 3D polygon mesh conversion (w/ many options)
• Optimized conversions to OpenGL/WebGL (with attributes, indexed, non-indexed)
• Flexible & customizable mesh vertex attribute generators
• Subdivision meshes (Catmull-Clark, Doo-Sabin, Butterfly)
• Parallel-transport frame sweep mesh generation from point sequences (skinning with arbitrary profiles, incl. profile morphing)
• 3D Lathe meshes from 2D curves
• 2D shape extrusions as 3D mesh (solid or walled)
• Delaunay triangulation of 2D point clouds
• Tesselation of simple 2D polygons (no holes)
• Basic SVG <path> parsing with different segment types
• Basic insetting of simple 2D polygons (no miter support)
• Shape subdivision (only lines, triangles, rects, quads, tetrahedrons)
• Shape boundary sampling (at fixed resolution or uniform distance)
• Sutherland-Hodgeman clipping of 2D polygons
• 3D Boolean (CSG) operations on meshes (union, difference, intersection)
• 3D geometry export (PLY, STL, OBJ, OFF formats)
• 3D mesh repair tools (T-junctions, unify vertices etc.)
• 2D/3D particle based Verlet Physics with customizable behaviors & constraints
• 2D convex hull
• 2D/3D quadtree/octree (mutable) for fast spatial indexing
• Automatic curve generation from point seqs (cubic, Chaikin etc.)
• Unfolding of 3D meshes to 2D (WIP) for digital fabrication

…

API scope

Since the core library does only deal with pure “platonic” geometry types, it doesn’t directly address any display or rendering functionality at all. However a number of support modules are provided, incl. OpenGL 3/4, WebGL & SVG support, to allow visualizing results and/or exporting generated assets. 2D/3D shape/mesh exporters are provided as well and together with sister libraries like thi.ng/luxor, it’s also possible to generate complete 3D scenes for high quality & high resolution non-realtime rendering using Luxrender now LuxCoreRender.

Furthermore, providing all functionality under a common API for both Clojure & Clojurescript, makes it trivial to offload heavy operations (e.g. large mesh processing) to the server side.

Project structure

core

source

These namespaces define the core functionality of this library, including the approx. 50 protocols and implementations of fundamental geometry types/functions like 2d/3d vector algebra, matrices, quaternion (+ related convenience constructors & conversions)

types

source

This directory contains all high-level 2d/3d data types with their implementations of the various core protocols. From a user perspective, these namespaces defined here provide most of this project’s core functionality.

utils

source

A number of often needed utility functions to deal with point collections, normals, path sampling, triangle properties etc. Also included here are shape intersection tests, curve subdivisions and 2D Delaunay triangulation.

mesh

source

Several tools & operations related to working with 3d meshes, incl. I/O, subdivisions, repair / cleaning, CSG / Boolean mesh merge, mesh generators (polyhedra, lathe etc.)

physics

source

This module provides a simple 2d/3d particle-based physics engine with Verlet integration and support for custom behaviors and constaints, both for individual particles and global. Particles can be connected with springs of varying stiffness as well as made interdependent using positive or negative force fields (attractors).

svg

source

A module to help with building SVG based visualizations of geom entities using hiccup compatible syntax. Includes a customizable 3D mesh renderer w/ software shader support.

viz

source

Declarative, highly customizable 2D data visualization module with ~10 different layout methods, 3 axis types, cartesian and polar domain support. Currently SVG only, but planned to be format-independent.

voxel

source

An experimental implementation of a in-memory sparse voxel tree (SVO) and related functionality to extract isosurface polygon meshes from the tree.

OpenGL & WebGL

source

This module provides a unified API to common OpenGL/WebGL functionality (context creation, shader management & presets, buffer management, textures, FBO etc.), as well as a number of optimized mesh types, conversion & rendering functions, cameras etc. to simplify the use of other geometry types defined in this project with OpenGL, both on the desktop and in the browser. The Clojure version wraps JOGL.

Release history & changelog

See CHANGELOG.org for further details.

Contributors

• @postspectacular
• @vl4dimir
• @skrat
• @acron0
• @arichiardi
• @Rovanion
• @reitzensteinm
• @stwind
• @fdb
• @jgmize
• @dimovich

License

(c) 2013 - 2023 Karsten Schmidt

This project is open source and licensed under the Apache Software License 2.0.