Bullet 3D documentation

Native-style access to the Bullet 3D world and collision objects owned by Defold. World creation, destruction and stepping remain controlled by Defold. The backend name refers to three-dimensional physics; this Defold version bundles Bullet 2.77, reported by bullet3d.get_version().

World, collision-object and rigid-body userdata are borrowed handles to Defold-owned objects. Shape userdata are borrowed logical child-slot handles attached to a collision object. Constraint userdata identify auxiliary native objects owned by this Lua API; destroy them explicitly when no longer needed. They are also destroyed automatically when a required body or world is destroyed.

A collision-object, rigid-body or shape handle becomes invalid when its collision object is deleted or reloaded. A world handle remains valid across collision-object reloads, but becomes invalid when its collection and physics world are destroyed. The corresponding is_valid() function is safe for checking a retained handle; every other operation rejects an invalid handle.

Version: alpha

Functions

local world = bullet3d.get_world()
local body = bullet3d.get_rigid_body("#collisionobject")
if world and body and bullet3d.rigid_body.is_valid(body) then
    bullet3d.rigid_body.apply_central_impulse(body, vmath.vector3(0, 10, 0))
end

-- A trigger is a collision object, not a rigid body.
local trigger = bullet3d.get_collision_object("#trigger")
assert(trigger and bullet3d.get_rigid_body("#trigger") == nil)