Build with solids and holes
Click a shape to add it, or drag it from the shape toolbar onto the workplane. The outline previews its placement. New shapes use a clear spot on the bed with a 2 mm gap from existing objects. Click an object or its row to select it; Shift-click adds or removes from the selection. Drag empty workplane space to draw a lasso; objects whose centers fall inside are highlighted. Hold Shift to add to the selection. Drag an object to move it across the workplane. Drag corner or edge squares to resize, the top square to stretch height with the bottom fixed, the cone to raise or lower the whole object, and curved arrows to rotate. All handles are available whenever an object is selected. Hold Shift while resizing to keep proportions. Rotation is free; hold Shift while rotating to snap to 15°. Cmd/Ctrl + Up raises the selection; Cmd/Ctrl + Down lowers it by the move-snap interval.
Model at the size you will print
Every coordinate is in millimeters. Dimensions are the unrotated size; World bounds show the current rotated extent. Position is the object center. Drop to bed sets the lowest point to Z = 0. Numeric entry is exact to the entered value, independent of drag snapping. Curves are faceted at the selected resolution.
Lay flat on the build plate
Select an object and click Lay flat. The side facing most directly toward the build plate is chosen automatically, rotated by the smallest angle, and dropped to Z = 0. Undo restores the original orientation and position. Curved shapes use the most downward-facing supporting mesh facet. Drop to bed preserves the existing rotation.
Cut, join, and align
Mark a shape as Hole, then overlap it with a solid. Gray diagonal shading appears on the intersecting part of the solid to mark what will be removed. The hole itself has lighter gray bands and a thin outline. Solids stay intact until Group or export. The hole shape remains editable. Select both and Group to commit the cut. Grouping performs a union and subtraction. Ungroup restores the source parts; transformed groups return baked meshes. Export also unites all included solids and subtracts all included holes, including ungrouped ones. Disconnected solids remain separate shells in one file.
Edges and measurements
Select one object and choose Edges. Click individual highlighted exterior edges, choose rounded Bevel or flat Chamfer, and adjust the radius or width. Apply saves the preview. Reopen Edges to revise the treatment until the object is otherwise reshaped. Undo restores the previous mesh. Ruler (R) places a movable reference on the workplane. Choose minimum endpoint, midpoint, or maximum endpoint; edit dimensions and signed offsets beside the object or in the ruler panel. World dimension changes on rotated objects bake their orientation into the mesh. Ruler inches affect display only; project coordinates remain millimeters.
Save your work
Save project downloads an editable .dadcad.json file. Open restores it. Local recovery is best-effort and depends on browser storage; save a project file before moving the app or closing the browser. Nothing is uploaded.
Print or use in Unity
STL is binary, Z-up, with coordinates in millimeters. STL does not store a formal unit; import into your slicer as millimeters without automatic resizing. OBJ uses meters and Y-up: a 100 mm part exports as 0.1 units. In Unity, verify the imported bounds with scale 1; importer conversion settings can affect the result. OBJ includes geometry only, not UVs, textures, or materials. GLB and glTF use Three.js GLTFExporter with coordinates in millimeters.
Controls
Right-drag: orbit. Middle-drag or Shift-right-drag: pan. Scroll: zoom. F: fit selection or all. D: drop to bed. Cmd/Ctrl + Up/Down: raise/lower. Delete: remove. Ctrl/⌘ D: duplicate. Ctrl/⌘ G: group. Ctrl/⌘ Z: undo. Ctrl/⌘ Shift Z: redo. Ctrl/⌘ S: save. Escape: clear selection.
Practical limits
Use a current desktop browser with WebGL2 and WebAssembly. Up to 300 objects; STL import up to 30 MB / 500,000 triangles. Open or inconsistent meshes are rejected. This is a mesh solid modeler, not a constraint sketcher: it has no recessed fillets, text, assemblies, or parametric sketch constraints. Edge treatments support exterior straight edges; curved rims and recessed edges are not supported. Printability still depends on wall thickness, supports, and your printer.