Track Builder - Camera Transition

Smoothly lerps the free camera from its current position/rotation to a target over a specified duration.

Overview

util_trackBuilder_cameraTransition provides a simple camera interpolation system. Call lerpTo(pos, rot, time) and the camera will smoothly transition using an ease-out curve. Used by the track builder for camera fly-throughs.

Module path: lua/ge/extensions/util/trackBuilder/cameraTransition.lua

Exports (M)

Internals

Interpolation

• Position: Linear interpolation: old * (1 - t) + target * t.
• Rotation: Quaternion nlerp: oldQuat:nlerp(targetQuat, t).
• Easing: Ease-out curve: t = 1 - (1 - linear_t)².

State

• oldPosition / oldQuat - captured from current camera at lerpTo call.
• targetPosition / targetQuat - the destination.
• transitionTime - total duration in seconds.
• remainingTime - counts down each frame.

Requirements

Only applies when in free camera mode (commands.isFreeCamera()). Uses core_camera.setPosRot() to update.

Instant Transition

If time <= 0, the camera is set immediately without interpolation.

How It Works

1. Call lerpTo(pos, rot, time) to start.
2. Current camera position/rotation is captured.
3. Each frame in onPreRender, the remaining time decreases and the camera is interpolated.
4. After time seconds, the camera reaches the target exactly.

Lua Examples

local camTrans = extensions.util_trackBuilder_cameraTransition

-- Smoothly move camera to a position over 2 seconds
camTrans.lerpTo(
  vec3(100, 200, 50),
  quatFromDir(vec3(0, -1, 0)),
  2.0
)

-- Instant teleport
camTrans.lerpTo(vec3(0, 0, 100), quat(0,0,0,1), 0)

Additional Exports

• M.lerpTo - (undocumented)
• M.onPreRender - (undocumented)