See geometry where it happens
Learners can move around geometric objects, inspect them from different viewpoints, and manipulate them with direct spatial actions instead of only orbiting a desktop camera.
Open-source project page
Build and explore dynamic 3D geometry directly in mixed reality.
Construct3D for Unreal is a modern open-source reimplementation of the original Construct3D learning environment. It brings embodied, dependency-driven geometry to current mixed-reality hardware: points, lines, planes, conics, surfaces, intersections, sweeps, booleans, and differential geometry remain live while the user edits the scene.
The system is intended for geometry teaching, guided student exploration, early-university STEM use, and research on immersive learning technologies.
New to the app?
The student guide is designed as a simple classroom instruction sheet. It lists all current construction methods, explains the selection-action workflow, and summarizes the menu tools in plain language.
- Use it for demonstrations, lab sessions, and first-time users.
- It complements the full technical documentation in the repository.
Why Construct3D?
The original Construct3D project explored how geometry becomes easier to understand when objects can be inspected, manipulated, and discussed in real three-dimensional space. The Unreal reimplementation preserves that educational idea while rebuilding the system on current mixed-reality hardware and a modern geometry kernel.
Built for teaching, not for CAD production
Construct3D emphasizes the construction process itself. The goal is to make relationships, dependencies, and variation visible rather than to produce polished engineering models.
Modernized as a public research artifact
The current system combines Unreal Engine, Open CASCADE Technology, Meta Quest hardware, documentation, and public source code so that the platform can be inspected, reused, and extended.
Construct3D in action
The two gallery images below correspond to Figures 3 and 4 from the current paper draft and show the range from advanced differential geometry to free-form surface interaction.
Figure 3
Advanced differential geometry on an intersection curve
A cone-cylinder intersection curve with tangent, Frenet frame, center of curvature, circle of curvature, and osculating sphere.
Figure 4
Free-form NURBS interaction with analytic geometry
An editable NURBS surface intersected with a cylinder, with a point on the intersection curve used for local curvature analysis.
Legacy Construct3D videos
The following three videos are linked from the original IMS Construct3D archive page and show the historical system in action.
Legacy video 1
Original Construct3D demonstration from the IMS project archive.
Watch on YouTubeLegacy video 2
Further archival demonstration of geometric interaction in the original system.
Watch on YouTubeLegacy video 3
Additional historical footage of Construct3D in action.
Watch on YouTubeDocumentation
The repository contains a full documentation set for setup, runtime architecture, geometry objects, construction methods, interaction, and release preparation.
README
Project overview, scope, supported features, and documentation map.
Open READMESetup
First-time setup, Meta plugin installation, and prerequisite workflow.
Open SetupBuild & Runtime
Build targets, runtime notes, packaging, and deployment details.
Open BuildRuntimeArchitecture
High-level system architecture, runtime layers, and dependencies.
Open ArchitectureOCCT Bridge
Geometry kernel integration and retained-shape behavior.
Open OCCTBridgeRelease Artifacts
Release packaging, snapshot contents, and distribution notes.
Open ReleaseArtifactsGeometry Objects
Object families, refresh behavior, dependencies, and failure boundaries.
Open GeometryObjectsConstruction Methods
Object-by-object construction reference for the current prototype.
Open ConstructionMethodsDifferential Geometry
Implemented curve and surface analysis tools.
Open DiffGeoSave, Load, Undo
Persistence model, dependency reconstruction, and scene recovery.
Open SaveLoadUndoVR Interaction
Menu system, multimodal interaction, stylus support, and hover strategy.
Open VRInteractionGlossary and Class Index
Terminology reference and class-oriented entry points into the codebase.
GlossaryClassIndex
For contribution workflow and repository conventions, also see CONTRIBUTING.md.