Student Guide

Simple instructions for using Construct3D in class

Construct3D follows a selection-action workflow: first select the geometric objects you want to use, then activate the construction or analysis command from the menu. The order of selection matters for several tools.

1. Hold the menu in the non-dominant hand Use the handedness toggle in the System tab if you want to swap menu hand and controller pen fallback.

2. Create or select with the stylus The front stylus button is the main action button for creating points, selecting geometry, and dragging points.

3. Select first, then activate the tool Most commands need the correct input objects before the button is pressed.

4. Save your scene regularly Save and Load are in the Files tab, while Undo and Redo are in the System tab.

Quick start

Tap the menu with the stylus tip. Hover above a button to read the input-output help. If a command does not work, check whether the correct number and type of objects are selected.

Points

Creating and moving points

Press the stylus front button in empty space to create a free point.
Select a curve or surface first, then create a point to constrain it to that geometry.
Press and hold the front button on a point to drag it.

Selection order

When order matters

For some tools, the last selected object defines the interpretation.
Example: with two lines in the Revolution tool, the first line is the axis and the second is the profile.
In Helical Sweep, select the pitch point before the swept point or profile.

General tip

Think in geometric dependencies

Constructed objects stay live. If you move an input point, downstream lines, planes, surfaces, intersections, and differential geometry objects update automatically.

Create geometry

These tools are available from the Create tab.

Point

Press the stylus front button in empty space to create a free point.
Select geometry first, then create a point to constrain it to a curve or surface.
Intersection and curvature tools can also generate derived points automatically.

Line / Normal / Tangent / Angle Bisector

2 points -> line
Point + surface or solid -> normal line
Point + circle / intersection curve / sweep curve -> tangent line
3 points -> angle bisector (middle point is the vertex)

Plane

3 points -> plane
2 points -> symmetry plane
2 lines -> plane
Point + line -> plane through point and line
Point + line (line selected last) -> normal plane
Point + surface -> tangential plane

Circle

3 points -> circle
Center point + radius point + normal line -> circle

Ellipse

Center point + major-axis point + ellipse point -> ellipse

B-Spline curve

2 or more interpolation points -> B-spline curve

Sphere

Center + point on sphere -> sphere
Center + 2 radius points -> sphere

Cylinder

Axis start + axis end + surface point -> cylinder
Axis line + surface point -> cylinder

Cone

Base center + apex + surface point -> cone
Axis line + surface point -> cone

Interpolated NURBS surface

4 corner points -> NURBS setup
Choose U and V between 2 and 8
Create an editable interpolated NURBS surface with a real point lattice

Tip: after creation, move the generated lattice points to reshape the surface dynamically.

Operations

These tools are available from the Ops tab.

Intersect

2 geometry objects -> intersection
Curve + any shape -> intersection point(s)
2 surface or solid shapes -> intersection curve

Supported curves include lines, circles, ellipses, B-splines, existing intersection curves, and sweep curves.

Revolve

Axis line + profile curve -> surface of revolution
Profiles can be line, circle, ellipse, B-spline, or an existing intersection curve

If both selected objects are lines, the first is the axis and the second is the profile.

Sweep

Path line or curve + point -> sweep curve
Path line or curve + profile object -> sweep surface

If both inputs are curves, select the profile curve last. Line paths use the finite selected line segment.

Helical Sweep

Axis line + pitch point + point -> helix
2 axis points + pitch point + point -> helix
Axis + pitch point + profile object -> helical sweep surface

Always select the pitch point before the swept point or profile object.

Boolean Difference / Intersection / Union

2 solids -> boolean result
Supported operands: cone, cylinder, sphere, surface of revolution, and existing boolean objects

Differential geometry

These tools are available from the DiffGeo tab.

Frenet Frame

Point on curve + curve -> Frenet frame

Circle of Curvature

Point on curve + curve -> circle of curvature

Center of Curvature

Point on curve + curve -> center of curvature

Osculating Plane

Point on curve + curve -> osculating plane

Osculating Sphere

Point on curve + curve -> osculating sphere

Dupin Indicatrix

Point on surface + surface -> Dupin indicatrix

Supported surfaces include cone, cylinder, surface of revolution, NURBS, sphere, boolean surfaces, and sweep surfaces.

System and file tools

These commands help manage the current construction and the interaction setup.

System tab

Undo / Redo -> move backward or forward in scene history
Delete -> remove selected objects
Deselect All -> clear the current selection
Hide / Show All -> hide selected objects or reveal hidden ones
New Construction -> start with an empty scene
Exit -> close the application

Extra controls

Left / Right Handed Menu -> move the menu to the other hand and swap controller pen fallback
Passthrough +/- -> change the passthrough brightness in steps of 0.1

Files tab

Save -> store the current construction
Load -> open the saved-drawings browser
Use the browser page buttons to move through stored slots

Need deeper technical detail?

The full repository documentation covers setup, geometry objects, differential geometry, save/load, runtime architecture, and the OCCT bridge in much more detail.

Open documentation links GitLab repository

Use this page as a compact classroom instruction sheet.
Use the repository docs for setup, developer, and research details.