Skip to content

Layer Maps

A layer map controls how layers are translated between input and output formats. It lets you rename layers, change colors, set visibility, define 3D properties, and filter which layers are exported.

LinkCAD supports two layer map file formats: JSON (recommended) and CSV.

JSON Format

JSON layer maps use a schema-validated format with richer metadata. This is the recommended format for new projects.

{
  "$schema": "https://schema.linkcad.com/layer-map-v1-schema.json",
  "version": 1,
  "units": "um",
  "layer_map": [
    {
      "input_layer": "METAL1",
      "output_layer": "M1",
      "order": 1,
      "comment": "Metal 1 layer",
      "color": "#FF0000",
      "visibility": true,
      "elevation": 1000,
      "thickness": 500,
      "material": 3,
      "extrude": true
    },
    {
      "input_layer": "VIA1",
      "output_layer": "V1",
      "order": 2,
      "color": "Blue",
      "stack": true,
      "thickness": 200
    }
  ]
}

Root Fields

Field Required Description
$schema Schema URL for editor validation
version Schema version (must be 1)
units Unit for elevation and thickness — nm, pm, um, mil, point, mm, cm, in, m, ft
layer_map yes Array of layer mapping entries

Entry Fields

Field Required Type Description
input_layer yes string Source layer identifier
output_layer string Target layer identifier
order integer Display order (JSON only — not available in CSV)
comment string Description or note
color string Layer color — hex (#FF0000) or X11 name (Red)
visibility boolean Whether the layer is visible
elevation number Z-coordinate, scaled by units (not allowed when stack is true)
thickness number Layer thickness, scaled by units
material integer Material index
extrude boolean Whether to extrude this layer in 3D export
stack boolean Stack layers automatically (mutually exclusive with elevation)

Tip

The JSON format supports order for controlling layer display order, which is not available in CSV layer maps.

CSV Format

Each row maps one input layer. Columns are comma-separated, with no header row:

input_layer,output_layer,comment,color,visibility,elevation,material,extrude,stack,thickness

Column Reference

Column Type Description
input_layer string Layer name or number from the imported file
output_layer string Layer name or number for the exported file
comment string Comment to apply to the exported layer
color color Display color — hex RGBA (#rrggbbaa) or color name (Blue, Red, etc.)
visibility bool Whether the layer is exported (true/false, 1/0, on/off)
elevation real Bottom Z-value for 3D export, in picometers
material integer Material identifier for 3D export
extrude bool Whether the layer is extruded in 3D
stack bool Stack this layer on top of the one below (mutually exclusive with elevation)
thickness real Layer thickness for 3D export, in picometers

Note

Strings containing commas must be quoted: "Metal 1, upper". Boolean values accept 1/0, true/false, or on/off.

Example

1,,,Blue,true,,,false,true,10000000000
2,,,Yellow,true,,,false,true,5000000000
3,,,Magenta,true,,,false,true,5000000000
4,,,Cyan,true,,,false,true,5000000000
5,,,"#ffc000",true,,,false,true,5000000000
6,,,"#ff00cc",true,,,false,true,10000000000

This maps GDSII layers 1–6 with custom colors, all visible, stacked with specified thicknesses.

JSON vs. CSV

Feature JSON CSV
order field yes no
Unit scaling for elevation/thickness yes no (always picometers)
Schema validation yes no
Structured metadata yes no

Using a Layer Map

In the GUI

  1. In the export options, check Apply Layer Map
  2. Click Browse and select your .csv file
  3. Proceed with export — the mapping is applied automatically

From the Command Line

linkcad.exe -i design.gds -o output.dxf `
  --layer-map LayerMap.csv --apply-layer-map

Legacy CLI Syntax

linkcad -LcApplyLayerMap=true -LcLayerMap="LayerMap.csv"

Tips

  • Omit columns you don't need — trailing commas are fine: 1,Metal1,,Blue,true
  • Set visibility to false to suppress a layer during export without deleting it
  • For 3D export, elevation and thickness are always in picometers (10⁻¹² meters)
  • Use stack=true for layers that should be placed on top of the previous layer instead of at an absolute elevation