Solid document format

Fields, units and accepted values in editable ALcad solid files.

ALcad solid documents use JSON and millimetres. This reference applies to Cloud and the Windows app. Editable downloads use the .alcad-solid.json extension.

Document fields

The current schema is alcad.solid/v7. ALcad opens versions alcad.solid/v1 through alcad.solid/v7 and saves them as alcad.solid/v7. Files can contain up to 65536 UTF-8 bytes.

Field	Value
`schema`	`alcad.solid/v7` for a new file
`unit`	`mm`
`name`	Document name, 1–80 printable characters
`features`	Ordered array of up to 32 features

Feature fields

Each feature has the fields below. All numeric values are finite. Three-value arrays follow X, Y, Z order.

Field	Value
`id`	Unique ID of 1–80 letters A–Z or a–z, digits, underscores or hyphens
`name`	Feature name, 1–80 printable characters
`shape`	`box`, `cylinder`, `extrude` or `revolve`
`operation`	`add`, `subtract` or `intersect`
`sizeMm`	Three dimensions, each from 0.05 to 10000 mm
`centerMm`	Three coordinates, each from -10000 to 10000 mm
`rotationDeg`	Three rotation angles, each from -360 to 360 degrees

Shapes and operations

Features apply in array order. The first feature uses add; subsequent features add, subtract or intersect the accumulated solid.

Shape	Dimensions and additional fields
`box`	`sizeMm` gives full X, Y and Z lengths.
`cylinder`	X and Y give the same diameter; Z gives height.
`extrude`	`profileMm` gives the XY contour. X and Y sizes match its bounds; Z gives extrusion height. Center X and Y place the profile origin; center Z places the extrusion midplane.
`revolve`	`profileMm` uses X as radius and Y as local Z. Radii are nonnegative. `revolveDegrees` is from 0.05 to 360. X and Y sizes equal twice the maximum radius; Z matches the profile height.

Profiles and sketches

A profileMm array describes a simple closed contour with 3–64 coordinate pairs. The final point connects to the first. Adjacent edges meet at corners. A document can contain up to 256 profile vertices. Coordinates range from -10000 to 10000 mm; each edge is at least 0.05 mm. Profile width and height are from 0.05 to 10000 mm, and area is at least 0.0025 mm².

In v7, extrusion and revolution features can include a sketch that drives the same contour. A rectangle sketch uses widthMm, heightMm and originMm. A constrained-profile sketch uses verticesMm and up to 128 constraints: horizontal, vertical, fixed, distance-x, distance-y, angle, relative-angle and edge-length.

Related guide

ALcad