Make Lost War Ads – Part 62 | Auto-Parent Progress Bars to Canvas (Prefab-Safe) | Unity Optimization

In Make Lost War Ads – Part 62, we continue directly from the previous tutorial and solve one of the most common Unity UI + prefab problems:
👉 How to safely attach progress bars to a Canvas at runtime without hard scene references.

When working with prefabs, especially enemies and allies, it is not recommended to reference scene objects like Canvas directly. Prefabs must remain generic, reusable, and decoupled from the scene. In this episode, we design a clean, runtime-based solution that automatically finds the correct Canvas and makes UI elements its child.

We create a new generic MonoBehaviour script that:

Searches the active scene at runtime

Locates the correct Canvas using its name

Sets the progress bar as a child of that Canvas

Avoids costly full-scene searches

Works perfectly with prefabs (enemy, ally, player)

Instead of using expensive methods like GameObject.Find() on thousands of objects, we leverage Scene.GetRootGameObjects(), which only scans root-level objects. This drastically improves performance, especially in:

Mobile games

Playable ads

Large combat scenes

Enemy-heavy environments

We also explain why this approach is faster, safer, and more scalable.

Key topics covered:
✔ Why prefabs should never depend on scene references
✔ Runtime canvas detection using Scene Management
✔ Optimizing searches by checking only root objects
✔ Auto-parenting UI elements with SetParent()
✔ Fixing missing Canvas & RectTransform issues
✔ Keeping UI systems prefab-safe and modular

By the end of this tutorial, your enemy and ally progress bars will:

Automatically attach to the correct Canvas

Work when spawned dynamically

Remain prefab-safe

Avoid NullReference errors

Stay optimized for performance

This is a must-watch episode if you’re building:

Lost War–style playable ads

Mobile or hybrid-casual games

Dynamic enemy systems

Scalable UI architectures in Unity

📌 This tutorial directly builds on Part 61, so make sure you’ve watched that episode first.

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#Unity #Unity3D #GameDev #IndieDev #PlayableAds #UnityUI #PrefabWorkflow #UnityOptimization #HealthBar #ProgressBar #EnemyUI #UnityTutorial #SceneManagement #LostWarAds #MobileGameDev #ShaderGraph #GameUI #UnityTips