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BeamNG.tech

Quads

This feature is supported as of BeamNG.tech and .drive version 0.3.7.8 to latest.

Quads are a way of placing two triangles at the same time. They share all of the triangle properties. A quad with nodes n1, n2, n3, n4 will create 2 triangles with the nodes n1, n2, n3 and n3, n4, n1 respectively, effectively creating a quadrangle. As with triangles, the nodes forming a quad should be chosen in a counter-clockwise order.

Quads are rarely used, mostly for surfaces that are perfectly rectangular. Even though there is no technical disadvantage of using them, they make it somewhat harder to understand the Jbeam files, especially when used together with triangles.

 Required arguments 

"quads": [
        ["id1:","id2:","id3:","id4:"],
        ["a", "b", "c", "d"],
],
id1:
name
string
type
The id of the first node of the first triangle and the last node of the second triangle
id2:
name
string
type
The id of the second node of the first triangle
id3:
name
string
type
The id of the last node of the first triangle and the first node of the second triangle
id4:
name
string
type
The id of the second node of the second triangle

 Optional arguments

dragCoef
name
number
type
100
default
Drag coefficient of the triangles as a percentage of a flat plate of the same size.
Typical values are around 10 for most exposed body panels.
skinDragCoef
name
float
type
0
default
Skin drag coefficient of the triangles as a percentage of a flat plate of the same size.
Additional drag coefficient defined along the triangle surface rather than across. Used to simulate paddle-like treads in mud tires. Usually not used otherwise.
liftCoef
name
number
type
dragCoef
default
Lift coefficient of the triangles as a percentage of a flat plate of the same size.
Values between 80 and 120 are commonly used for spoilers.
stallAngle
name
number
type
0.58
default
Angle of attack in radian at which the triangles will start to stall and produce less lift.
triangleType
name
string
type
NORMALTYPE
default

The available triangle types are :

“NORMALTYPE” : Used for most applications

“NONCOLLIDABLE” : Have no collisions or aero. Used to keep the anticlip system working with nodes that have collisions but no triangles like suspension and exhaust.

pressureGroup
name
string
type
Defines a group of triangles as being a pressure volume. Used for flotation and pressure simulation.
pressurePSI
name
number
type
Sets the pressureGroup pressure in PSI
pressure
name
number
type
Sets the pressureGroup pressure in Pascal
breakGroup
name
string
type
Used to allow triangles to break when triggered by beams in the same break group.
optional
name
boolean
type
false
default
Deactivates errors when some of the nodes forming the quad are missing.
This is used for cases where some of the nodes that make up the quad are located in an optional component.
groundModel
name
string
type
asphalt
default
Ground model of the triangles. Determines friction behavior.
As of version 0.39.1.0 the following physics materials are available:
METAL, PLASTIC, RUBBER, GLASS, WOOD, FOLIAGE, CLOTH, WATER, ASPHALT, ASPHALT_WET, SLIPPERY, ROCK, DIRT_DUSTY, DIRT, SAND, SANDY_ROAD, MUD, GRAVEL, GRASS, ICE, SNOW, FIRESMALL, FIREMEDIUM, FIRELARGE, SMOKESMALLBLACK, SMOKEMEDIUMBLACK, STEAM, RUMBLE_STRIP, COBBLESTONE, FOLIAGE_THIN, SPIKE_STRIP
externalCollisionBias
name
string
type
Biases one side of the collision detection system.

On the biased side, collision triangles will be physically ’thicker’ than on the other, with the collision being detected earlier. Thicker collision means less chance of nodes clipping through the triangle on high speed impacts, thinner means the structures can be positioned closer to each other on spawn. This is useful for very small objects that will typically only collide with things from one side.

Allowed values are:

  • oneWayIn: Only the inner side of the triangle is collidable. Any node can easily pass through from the outer side, but can’t pass from the inner side.
  • in: Both sides of the triangle have equal bias. On medium speed collision there is a chance of nodes clipping through the triangle from either side.
  • No value provided: Default bias, the outer side is biased compared to the inner side. Most low speed collisions apply on both sides, but high speed ones have a chance of only applying on the outer side.
  • out: The outer side is very biased compared to the inner side. Even on low speed impacts, nodes have a high chance of passing through the triangle from the inner side.
  • oneWayOut: Only the outer side is collidable. The exact opposite of oneWayIn.

 Simple Example 

"quads": [
        ["id1:","id2:","id3:", "id4:"],
        {"dragCoef":15},
        ["er_l1l","er_l3l","er_l4l", "er_l2l"],
        ["er_l1r","er_l2r","er_l4r", "er_l3r"],
        {"dragCoef":0},
        {"group":""},
],
Last modified: July 29, 2026

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