In 3D solids, click Add bracket example. The CAD engine downloads to this device for the first calculation.
In Edit base dimensions, change the width of 120, depth of 60, and height of 8mm.
Click a hole in the feature history and edit its position or radius. The remaining features recalculate in order.
Inspect the interior using Front, Top, Right, and the section view. STEP contains actual solids; STL contains triangulated surfaces.
Click Save CAD project file to keep the edit history too. STEP files do not contain this app's feature history.
2. Create a solid from a 2D drawing
Set two points of a known length in a photo, or use Numeric drawing to create shapes in mm.
Select a rectangle, circle, or closed outline and click Extrude to 3D. You can change thickness in the 3D base dimensions.
For a constrained sketch, use Constrained sketch in 3D to enter points and horizontal, vertical, or length conditions. 0 degrees of freedom means all coordinates are constrained. Redundant constraints may remain.
Use Send 2D projection to bring part edges into the drawing and add dimensions. This transfers a copy; it is not automatic synchronization.
3. Reconstruct 3D from overlapping photos
Under ‘Photos → 3D’, choose ‘Photogrammetry’. Keep the object still and move the camera, capturing enough of the same patterns in neighboring photos.
Add photos in shooting order and reconstruct with ‘Quick preview’ first. If photos are shown as unconnected, add photos from neighboring angles.
Once the surface is built, choose ‘Select two surface points’ and click the two points you measured with a ruler. Enter their actual distance in mm and apply it.
If needed, choose the area to keep under Crop the background. Send the model to CAD to review position, rotation, and print checks, or save it as a color PLY.
If photo alignment is good, recalculate with ‘Standard’ or ‘Detailed’. Set the actual length again after each new reconstruction. On phones, start with Quick preview.
Camera position estimation, depth calculation, and surface generation run on your device. Surface colors are vertex colors, not photographic texture maps. Hidden areas and the accuracy of manufacturing dimensions must be verified by physical measurements.
Approximate the outer shape from straight-on photo silhouettes
Choose ‘Silhouette approximation · Straight-on photos’ to use the existing directional silhouette method.
Measure and enter the object's width, depth, and height. Light the surface evenly and use a background color distinct from the object.
Take front, right, and top photos. Include the whole object with a margin; zoom from farther away to reduce perspective.
Set the actual shooting direction for every photo. Automatic labels are only suggestions based on upload order, so always verify them.
Adjust separation until the orange mask matches the object, or use Draw outline to click around its boundary.
Use Photos needed next to fix missing directions, blur, and cropped edges. Reconstruction is blocked if the same photo is registered under different directions.
Click Create 3D from photos. The result is a grid-based approximate exterior mesh; interiors, recesses, and surface colors are not reconstructed. Use it separately from CAD solids built with measured dimensions.
Files and current support
File
Contents
.mellow.json
Existing designs, 2D drawings, and dimensions. Transfers both ways with the Design app.
.mellowcad.json
Separate 3D project: parameters, feature history, assembly joints, CAM setup, reconstruction photos, and photo meshes.
STEP
CAD solid exchange. Photo meshes are not included.
STL
Triangulated surface of the selected part. Interpret units as mm.
XYZ · XYZRGB
Scanned point coordinates and color RGB. Import an external 3D file, select column configuration and units, and View/Save All Points in a separate window. Does not convert to faces or solids.
PLY point cloud
View the point clouds of X·Y·Z and optional RGB in a separate window and save them in ASCII and binary format. It selects the length unit directly and rejects other properties without discarding them. PLY with faces leads to importing existing mesh.
DXF
2D lines, circles, and polylines in mm. Only these three types can be imported; any unsupported entity stops the entire import.
Tutorial: Assemble two parts
Open Advanced tools in 3D Solids and choose ‘Assembly’. Use ‘Add hinge assembly example’ to create a base and arm.
Move the slider to rotate the arm. Save with ‘Apply this position’, then use ‘Check interference at current position’ to check for overlapping parts.
For your own assembly, choose the reference and moving parts, select anchors such as top or bottom, and apply a fixed, hinge, or slider joint. Enter coordinates directly for precise anchors.
Tutorial: Surface-modeled part
In ‘Surface modeling’, change section sizes and Z heights in the multi-section loft. Add sections to shape intermediate regions.
Switch to ‘Profile sweep along a curve’ to move a rectangle, ellipse, or other section along an XYZ path. After ‘Apply solid’, edit it again through Edit base dimensions.
STEP exchanges actual solids; 3MF/STL save surfaces for printing. Photo meshes do not automatically generate feature histories.
Tutorial: Pocket machining toolpath
In ‘Toolpaths’, start with the example: stock 100×80×12mm, tool diameter 6mm, rectangular pocket 50×35mm, depth 3mm. Example speeds are not material-specific recommendations.
Choose ‘Calculate toolpaths’ and play the result. Depth goes negative from the stock top at Z=0. Recalculate after changing tools, feeds, or depth.
Use ‘Save setup’ to keep it in the CAD project. Check the machine's G54 origin, tool offsets, workholding, and travel limits before saving G-code, then verify with a dry run on the machine.
Photogrammetry estimates a mesh from multiple photos; it does not recover an editable CAD feature history automatically. Sketch constraints mainly cover straight-sided polygons, without curve tangency. Assemblies use single-parent fixed, hinge, or slider joints, without closed-loop mechanism analysis. Machining uses single-tool 2.5D paths, without 3-axis freeform or 5-axis machining or fixture collision analysis.
DXF exports ellipses and curves as approximate polylines. 2D→3D preserves rectangles and ellipses as exact geometry and approximates free curves with point sequences. Multi-section lofts support 2~12 sections; curved sweeps support circular, elliptical, rectangular, or polygonal sections and B-spline paths. The CAD engine calculates basic solids, holes, and fillets. Verify drawings, dimensions, and tolerances before manufacturing.
Calculations and saving run on your device. No server calculations or photo uploads. Downloading app and engine files requires a network connection. If a large model is slow on a phone, cancel, lower the resolution, or open the project file on a PC.