World:interpolate

Edit

Interpolates collider poses between their previous pose and their current pose. Methods like Collider:getPosition and Collider:getOrientation will return the smoothed values.

After World:update is called, any interpolation is reset and World:interpolate will need to be called again to recompute the interpolated poses.

This can be used to decouple the physics tick rate from the rendering rate. For example, the physics simulation can be run at a fixed rate of 30Hz, and collider poses can be interpolated before rendering. This leads to a more stable simulation, and allows the physics rate to be increased or decreased as desired, independent of the current display refresh rate.

World:interpolate(alpha)

Example

An example of a fixed timestep physics update.

function lovr.load()
  world = lovr.physics.newWorld()
  time = 0
  timestep = 1 / 30 -- 30Hz
end

function lovr.update(dt)
  time = time + dt

  -- Update as many times as needed, if any
  while time >= timestep do
    world:update(timestep)
    time = time - timestep

    -- Potentially do per-tick gameplay logic here
    -- like check for collisions or apply impulses
  end

  -- Interpolate the colliders
  local alpha = time / timestep
  world:interpolate(alpha)
end

function lovr.draw(pass)
  -- Draw colliders as usual, using `Collider:getPose` etc.
end

See also

• World