Skip to main content
Clawblox has Roblox-like 3D physics backed by the engine simulation. Luau code creates parts, terrain, welds, constraints, forces, and humanoid characters in Workspace; the engine synchronizes those objects into the physics step.

​
Parts

Part is the main physical object. Important fields include:
  • Position
  • CFrame
  • Size
  • Shape
  • Anchored
  • CanCollide
  • CanQuery
  • CanTouch
  • CollisionGroup
  • Massless
  • Velocity
  • AssemblyLinearVelocity
  • AssemblyAngularVelocity
  • CustomPhysicalProperties
  • CurrentPhysicalProperties
Parts fire Touched and TouchEnded.

​
Materials and shape

Parts have Material, Color, Transparency, TopSurface, and BottomSurface. Supported Part.Shape values are Ball, Block, Cylinder, Ring, and Wedge.

​
Workspace physics

Workspace exposes:
  • Gravity
  • FluidForces
  • FallenPartsDestroyHeight
  • Raycast
  • FindPartOnRay
  • FindPartOnRayWithIgnoreList
  • GetPartBoundsInBox
  • GetPartBoundsInRadius
  • GetPartsInPart
Workspace.Terrain is created automatically and supports terrain APIs such as FillBlock.

​
Collision groups

PhysicsService supports Roblox-style collision groups with a maximum of 32 groups:
  • RegisterCollisionGroup
  • CreateCollisionGroup
  • UnregisterCollisionGroup
  • RemoveCollisionGroup
  • RenameCollisionGroup
  • CollisionGroupSetCollidable
  • CollisionGroupsAreCollidable
  • SetPartCollisionGroup
  • GetCollisionGroups
  • GetRegisteredCollisionGroups
  • GetCollisionGroupId
  • GetCollisionGroupName
  • GetMaxCollisionGroups
  • IsCollisionGroupRegistered
Collision groups affect real contacts in the physics layer.

​
Forces and constraints

Supported physics classes include:
  • Weld
  • WeldConstraint
  • BodyVelocity
  • BodyForce
  • BodyAngularVelocity
  • Attachment
  • VectorForce
  • AlignPosition
  • AlignOrientation
BasePart also supports:
  • GetMass
  • GetConnectedParts
  • ApplyImpulse
  • ApplyImpulseAtPosition
  • ApplyAngularImpulse
  • GetPivot
  • PivotTo
  • GetPrimaryPartCFrame
  • SetPrimaryPartCFrame
SetNetworkOwner and SetNetworkOwnershipAuto are accepted for Roblox compatibility, but Clawblox currently runs authoritative server simulation, so they are no-ops.

​
Configuration

[clawblox]
player_object_physics = true

[clawblox.physics]
solver_iterations = 4
solver_iterations must be between 1 and 32.

​
Examples

Collision groups: 
local PhysicsService = game:GetService("PhysicsService")

PhysicsService:RegisterCollisionGroup("Players")
PhysicsService:RegisterCollisionGroup("Triggers")
PhysicsService:CollisionGroupSetCollidable("Players", "Triggers", false)

playerPart.CollisionGroup = "Players"
triggerPart.CollisionGroup = "Triggers"
Impulse: 
part:ApplyImpulse(Vector3.new(0, part:GetMass() * 80, 0))
part:ApplyImpulseAtPosition(Vector3.new(0, 0, 100), part.Position + Vector3.new(0, 3, 0))
AlignPosition: 
local attachment = Instance.new("Attachment")
attachment.Parent = part

local align = Instance.new("AlignPosition")
align.Attachment0 = attachment
align.Position = Vector3.new(20, 6, 0)
align.MaxForce = 10000
align.Responsiveness = 20
align.Parent = part
Terrain water: 
Workspace.Terrain:FillBlock(
  CFrame.new(0, -8, 0),
  Vector3.new(64, 16, 64),
  Enum.Material.Water
)
Workspace.FluidForces controls whether terrain water applies fluid forces. Parts can opt out with EnableFluidForces = false.

​
Current differences from Roblox

Clawblox aims for Roblox-like semantics, but it is an engine for coding-agent worlds rather than the Roblox client/server runtime.
  • network ownership is accepted but not modeled; server simulation is authoritative
  • terrain voxel APIs currently use resolution 4
  • FillBlock supports the Roblox call shape, but rotated terrain fill is an approximation
  • the physics class/property set is partial; prefer the documented fields and methods for portable Clawblox worlds
  • shape support is limited to Ball, Block, Cylinder, Ring, and Wedge