Assetto Corsa CSP - Custom XY Chaser Camera

camera.lua

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-- Simple camera script with X and Y-axis rotation.
--------

-- Extra thing for looking around:
local lookXDirection = smoothing(0, 10)
local lookYDirection = smoothing(0, 10)

-- Will be called each frame:
-- Note: `dt` is time passed since last frame, `cameraIndex` is 1 or 2, depending on which camera is
-- chosen.
function update(dt, cameraIndex)

  smoothing.setDT(dt)

  -- Get AC camera parameters with some corrections to be somewhat compatible:
  local cameraParameters = ac.getCameraParameters(cameraIndex)
  local distance = cameraParameters.distance + 0.8
  local height = cameraParameters.height 
  local pitchAngle = -cameraParameters.pitch

  -- Get car position and vectors:
  local carPos = ac.getCarPosition()
  local carDir = ac.getCarDirection()
  local carUp = ac.getCarUp()
  local carRight = math.cross(carDir, carUp):normalize()

  -- Extra thing for joystick support:
  local joystickLook = ac.getJoystickLook()
  lookXDirection:update(
    (ac.looksLeft() and ac.looksRight() or ac.looksBehind()) and math.sign(lookXDirection.val) or
    ac.looksLeft() and 0.5 or
    ac.looksRight() and -0.5 or
    joystickLook ~= nil and -joystickLook.x or 0)
  local cameraXAngle = lookXDirection.val * math.pi
  lookYDirection:update(
    (
      joystickLook ~= nil and -joystickLook.y or 0
    )
  )
  -- cameraYAngle = cameraYAngle + lookYDirection.val * math.pi
  local cameraYAngle = lookYDirection.val * math.pi

  -- Sine and cosine for camera angle
  local sinX, cosX = math.sin(cameraXAngle), math.cos(cameraXAngle)

  -- Up direction for camera (could be used for horizon lock):
  local cameraUp = (carUp + vec3(0, 3, 0)):normalize()

  -- Set camera position:
  ac.Camera.position = carPos 
    + (carRight * sinX - carDir * cosX) * distance
    + (carUp * math.clamp(-cameraYAngle, -math.radians(90), math.pi))
    + vec3(0, height, 0)

  -- Find camera look
  local cameraLookPosOffset = carDir + carUp * (1 - math.abs(lookXDirection.val ))
  local cameraLook = (carPos + cameraLookPosOffset - ac.Camera.position):normalize()

  -- Use for `pitchAngle`:
  cameraLook:rotate(quat.fromAngleAxis(math.radians(pitchAngle), carRight))

  -- Set camera look:
  ac.Camera.direction = cameraLook

  -- Set other parameters:
  ac.Camera.up = (carUp + vec3(0, 3, 0)):normalize()
  ac.Camera.fov = 60

end