About 3D Shape Builder
Build 3D models with primitives, boolean operations, sculpting, draw-on-surface, and extrude. Export STL, OBJ, 3MF, and glTF for 3D printing and game development. Free browser-based 3D modeler.
How to use
- Click the Add Shape button (A) in the left toolbar or use the shape palette to insert a 3D primitive. Choose from 20+ shapes including box, sphere, cylinder, torus, arch, star, helix, and threaded fasteners. Each shape appears on the build plate ready for manipulation.
- Select objects by clicking them, then use the transform tools: Move (G) slides on the XZ plane, hold Shift for vertical. Rotate (R) spins with L/R for Y-axis, U/D for X-axis, Shift for Z-axis. Scale (S) resizes uniformly. Stretch (T) resizes along one axis based on the face you click.
- Use Boolean Cut to subtract shapes. Click the scissors tool, select the target object, then select the cutter. The cutter is subtracted from the target. Enable 'Keep cutter' to reuse the same cutting shape on multiple objects. Floor cut removes everything below the ground plane.
- Draw on Surface mode (D) lets you draw rectangles, circles, and lines directly on any face. Click a face to enter drawing mode — the camera aligns automatically. Draw your shape, then select it and click Extrude in the Properties panel to push it outward (adds material) or pull it inward (removes material).
- Enter Sculpt mode (X) to deform mesh surfaces with 9 brush types. Adjust radius and strength with the sliders. Hold Shift to invert any brush. Click Subdivide to add more geometry for finer detail. Each brush stroke has its own undo/redo stack.
- Use Sub-object selection (1=Face, 2=Edge, 3=Vertex) for precise editing. Color individual faces, extrude them, flip normals, bevel edges, move vertices, or merge nearby vertices. Shift-click for multi-select.
- Export your finished model: STL for 3D printing, OBJ for universal compatibility, 3MF for Bambu Lab/Prusa/Cura, or glTF for web and game engines. Configure the base plate (buffer and thickness) for multi-part prints. Save your work as .skl files to continue later.
Frequently asked questions
What 3D shapes can I create with this tool?
Over 20 primitives: box, sphere, cylinder, cone, torus, wedge/ramp, slab, stairs, half-pipe, arch, capsule, pyramid, prism, disc, tube, helix, star, ring, L-bracket, icosphere, bowl, arrow, and threaded fasteners (metric, imperial, NPT, specialty). Each shape uses high polygon counts (64 radial segments) for smooth 3D-print-quality curves. Threads use the real-world thread library with accurate pitch, major/minor diameters, and ISO specifications.
Can I export models for 3D printing?
Yes. Four export formats are supported: STL (binary, universal 3D print format), OBJ (widely supported mesh format), 3MF (modern format with color support for Bambu Lab, Prusa, Cura), and glTF/GLB (web-optimized for Unity, Godot, three.js). The tool includes a configurable base plate with adjustable buffer and thickness for keeping multi-part prints together. Objects below the ground plane are automatically clipped using CSG for watertight geometry.
How do boolean operations work?
Boolean Cut uses CSG (Constructive Solid Geometry) via a BSP tree algorithm. Click the scissors tool, select your target object, then click the cutter shape. The cutter volume is subtracted from the target, producing clean geometry with proper face normals. You can enable 'Keep cutter' to reuse the same cutting tool on multiple objects. Floor cut removes everything below Y=0 with a proper cap surface — useful for preparing objects that need to sit flat on the print bed.
What is the Draw on Surface feature?
Draw mode (D) lets you draw 2D shapes directly on the surface of any 3D object or the ground plane. Pick a face to draw on — the camera automatically snaps to face it head-on. Draw rectangles (with precise W/H dimension input), circles (with radius input), or lines. Vertex snap points appear on the surface for precision. After drawing, select the created face and click Extrude in the Properties panel: positive depth adds material (CSG union), negative depth removes it (CSG subtract). This workflow mimics professional CAD 'sketch on face + extrude' operations.
Does the sculpting system support multiple brushes?
Nine sculpt brushes: Push/Pull (move surface along normal), Smooth (average neighboring vertices), Flatten (project to plane), Inflate (expand along vertex normals), Pinch (pull toward brush center), Crease (pinch + push for ridges), Grab (drag mesh like clay), Clay (additive layer building), Twist (rotate around brush axis). All use Wyvill kernel falloff for smooth results. Adjustable radius and strength. Hold Shift to invert. Click Subdivide to split triangles for more sculpting detail (up to 80k vertices).
Can I edit individual faces, edges, and vertices?
Yes. Press 1 for Face select, 2 for Edge select, 3 for Vertex select. Face mode: color faces (24-color palette), extrude faces outward, delete faces, flip normals. Edge mode: bevel edges (chamfer), mark edges as sharp. Vertex mode: move vertices by dragging (Shift for vertical), merge nearby vertices to a single point, delete vertices and their connected faces. Shift-click for multi-select in all modes.
What units and printers are supported?
Display units: millimeters (mm), centimeters (cm), and inches (in). Grid snap adjusts to match the selected unit. Build plate presets: Bambu Lab X1C/P1S/A1 (256x256mm), Bambu Lab A1 mini (180x180mm), Ender 3 (235x235mm), Prusa MK4 (250x210mm). The build plate shows as a checkerboard with a border outline and grid overlay. 1 world unit = 10mm internally.
Is my data stored or uploaded anywhere?
No. Everything runs 100% in your browser using WebGL (Three.js r128) for rendering and CSG.js for boolean operations. Models never leave your device. Exports are generated as local downloads. Save/Load uses .skl files (JSON format) stored on your computer. No accounts, no cloud, no tracking.
Part of ToolFluency’s library of free online tools for Creative. No account needed, no data leaves your device.