Materials | Reference

Materials give parts realistic appearance using physically based rendering (PBR). Each material defines visual properties like color, metallic reflection, and surface roughness, plus optional physical data for mass calculations.

Material Properties

Every material has these core properties:

Property	Type	Range	Description
`color`	`[r, g, b]`	0.0 - 1.0	Base color in RGB
`metallic`	`number`	0.0 - 1.0	0 = plastic/dielectric, 1 = metal
`roughness`	`number`	0.0 - 1.0	0 = mirror smooth, 1 = fully rough
`density`	`number`	optional	kg/m^3 for mass calculations

The metallic property controls how the material reflects light. Metals reflect the environment with their base color tinting the reflection. Non-metals (plastics, wood) have white specular highlights.

Roughness Examples

Value	Appearance
0.0 - 0.1	Mirror-like, sharp reflections (chrome, polished glass)
0.2 - 0.4	Glossy finish (polished metal, lacquered wood)
0.5 - 0.7	Satin/matte finish (brushed metal, plastic)
0.8 - 1.0	Fully diffuse (rubber, concrete, foam)

Built-in Materials

vcad includes 31 preset materials organized by category.

Metals

Key	Name	Density (kg/m^3)
`aluminum`	Aluminum	2700
`steel`	Steel	8000
`brass`	Brass	8500
`copper`	Copper	8960
`titanium`	Titanium	4500
`chrome`	Chrome	7190
`gold`	Gold	19300
`silver`	Silver	10490

Plastics

Key	Name	Density (kg/m^3)
`abs-white`	ABS White	1050
`abs-black`	ABS Black	1050
`abs-red`	ABS Red	1050
`abs-blue`	ABS Blue	1050
`pla`	PLA	1240
`petg`	PETG	1270
`nylon`	Nylon	1150
`resin`	Resin	1200
`acrylic`	Acrylic	1180
`rubber`	Rubber	1100

Organic

Key	Name	Density (kg/m^3)
`oak`	Oak	750
`walnut`	Walnut	650
`leather`	Leather	900
`cork`	Cork	200
`bamboo`	Bamboo	400

Glass

Key	Name	Density (kg/m^3)
`glass`	Glass	2500
`glass-tinted`	Tinted Glass	2500

Composites

Key	Name	Density (kg/m^3)
`carbon-fiber`	Carbon Fiber	1600
`fiberglass`	Fiberglass	1800
`kevlar`	Kevlar	1440

Other

Key	Name	Density (kg/m^3)
`concrete`	Concrete	2400
`ceramic`	Ceramic	2300
`foam`	Foam	50

Custom Materials

Define custom materials in your document's materials dictionary:

{
  "materials": {
    "my-purple-plastic": {
      "name": "my-purple-plastic",
      "color": [0.5, 0.2, 0.8],
      "metallic": 0.0,
      "roughness": 0.5,
      "density": 1100
    }
  }
}

namestringrequired

Unique identifier for the material. Use lowercase with hyphens.

color[number, number, number]required

RGB color values from 0.0 to 1.0.

metallicnumberrequired

Set to 0.0 for plastics, wood, and most non-metals. Set to 0.8-1.0 for metals.

roughnessnumberrequired

Surface roughness from 0.0 (mirror) to 1.0 (matte).

densitynumberrequired

Optional. Density in kg/m^3 for mass calculations.

Assigning Materials to Parts

In the UI

Select a part in the viewport or feature tree
Open the Material Selector in the properties panel
Click a material to apply it

The material selector provides:

Live preview: Hover over a material to preview it on the selected part
Recent materials: Your last 6 used materials appear at the top
Favorites: Star materials to pin them for quick access

In Code (MCP)

When creating parts via the MCP server, specify the material key:

{
  "parts": [
    {
      "name": "bracket",
      "material": "aluminum",
      "primitive": {
        "type": "cube",
        "size": { "x": 50, "y": 30, "z": 5 }
      }
    }
  ]
}

In .vcad Files

Materials are assigned per-part in the document's roots array:

{
  "roots": [
    { "root": "op-001", "material": "steel" },
    { "root": "op-002", "material": "abs-black" }
  ]
}

Mass Calculations

When a material has a density value, vcad can calculate part mass:

mass = volume * density

Volume is computed from the part geometry. The Inspect panel displays mass when a material with density is assigned.

For assemblies, total mass is the sum of all instance masses, accounting for each instance's material assignment.