Property Operations

About 2 min

Property Operations

Set and retrieve entity properties, including color, layer, linetype, lineweight, transparency, and more.

Online Examples

Example	Description	Link
Color Settings	`color`, color index, and RGB true color	Online Demo{target="_blank"}
Layer Settings	Usage of the `layer` property	Online Demo{target="_blank"}
Linetype Settings	Usage of `lineType` and `lineTypeScale`	Online Demo{target="_blank"}
Lineweight Settings	`lineWeight`, standard lineweight values, layer lineweight, and `LWDISPLAY`	Online Demo{target="_blank"}
Transparency Settings	Usage of `transpMgr`	Online Demo{target="_blank"}
Apply Defaults	Usage of `setDefaults`	Online Demo{target="_blank"}
Extended Data	Attach custom data to entities and export / reload with DWG	Online Demo{target="_blank"}
Visibility	`visible` property (`DXF 60`) to show / hide a single entity	Online Demo{target="_blank"}

Core API

Color Settings

WebCAD supports two color representations:

// Indexed colors (1-255)
entity.color = 1;  // Red
entity.color = 2;  // Yellow
entity.color = 3;  // Green

// RGB true color
entity.color = 0x1000000 + 0xFF8000;  // Orange (RGB: 255, 128, 0)

Lineweight Settings

Lineweight values use 0.01 mm as the unit. For example, 25 means 0.25 mm.

Standard lineweight values

Value	Width	Value	Width	Value	Width
`0`	`0.00 mm` (thin)	`50`	`0.50 mm`	`140`	`1.40 mm`
`5`	`0.05 mm`	`53`	`0.53 mm`	`158`	`1.58 mm`
`9`	`0.09 mm`	`60`	`0.60 mm`	`200`	`2.00 mm`
`13`	`0.13 mm`	`70`	`0.70 mm`	`211`	`2.11 mm`
`15`	`0.15 mm`	`80`	`0.80 mm`	`-1`	`ByLayer`
`18`	`0.18 mm`	`90`	`0.90 mm`	`-2`	`ByBlock`
`20`	`0.20 mm`	`100`	`1.00 mm`	`-3`	`Default` (`0.25 mm`)
`25`	`0.25 mm`	`106`	`1.06 mm`
`30`	`0.30 mm`	`120`	`1.20 mm`
`35`	`0.35 mm`
`40`	`0.40 mm`

Set entity lineweight

const line = new LineEnt([0, 0], [100, 0]);
line.setDefaults();
line.lineWeight = 50;   // 0.50 mm
Engine.addEntities(line);

// Special values
line.lineWeight = -1;   // ByLayer
line.lineWeight = -2;   // ByBlock
line.lineWeight = -3;   // Default, uses LWDEFAULT (0.25 mm)

Set layer lineweight

doc.layers.add("ThickLineLayer", {
    color: 1,
    lineWeight: 100  // 1.00 mm
});

// Set entity to ByLayer to inherit layer lineweight
line.lineWeight = -1;
line.layer = "ThickLineLayer";

Lineweight display switches

LWDISPLAY and SHOW_LINEWEIGHT must both be enabled for lineweight to be rendered.

// LWDISPLAY: document-level switch, saved to DWG
Engine.currentDoc.docEnv.LWDISPLAY = true;
Engine.currentDoc.docEnv.LWDISPLAY = false;

// SHOW_LINEWEIGHT: frontend global switch, not exported to DWG
SystemConstants.SHOW_LINEWEIGHT = true;
SystemConstants.SHOW_LINEWEIGHT = false;

// Regenerate after switching
Engine.regen(true);

Command-line toggle

Enter LWDISPLAY (alias LW) in the command line to toggle lineweight display interactively:

Command: LW
Current lineweight display LWDISPLAY = OFF
Lineweight display [ON/OFF] <ON>: 
LWDISPLAY set to ON

This command sets both LWDISPLAY and SHOW_LINEWEIGHT and refreshes the view automatically.

LWDISPLAY vs SHOW_LINEWEIGHT

LWDISPLAY is the standard DWG system variable. It is saved with the document and matches AutoCAD's lineweight button
SHOW_LINEWEIGHT is a frontend rendering switch and is not saved to the file
The LWDISPLAY command (alias LW) controls both and is the easiest way to switch lineweight display

Apply Default Properties

After creating an entity, call setDefaults() to apply current system defaults:

const line = new LineEnt([0, 0], [100, 100]);
line.setDefaults();  // Apply current layer, color, linetype, and other defaults

// Custom properties should be set after setDefaults()
line.color = 1;
line.layer = "AnnotationLayer";

Engine.addEntities(line);

Visibility

Control entity-level show / hide, corresponding to DXF Group Code 60:

// Hide entity
entity.visible = false;

// Show entity
entity.visible = true;

// Read visibility
console.log(entity.visible); // true or false

Difference from Layer Visibility

Layer visibility (layer.layerOn) controls the display of the whole layer and affects all entities on that layer
Entity visibility (entity.visible) controls only one entity and does not affect others on the same layer

Extended Data (`XData`)

Attach custom data to an entity:

// Set extended data
entity.xdata = {
    appName: "MyApp",
    data: { key: "value" }
};

// Get extended data
const xdata = entity.xdata;