16 Detect collissions and Destroy Objects using custom methods
00:00 Session Goal – Auto-spawn animals + destroy on collision
01:21 Open Project – Unity Hub → Deer Game + Patreon starter zip option
02:21 SpawnManager Overview – Current spawn happens with S key
03:13 Create Custom Method – Make SpawnRandomAnimal() and move spawn code into it
04:40 Call Method on Key – Replace spawn code with SpawnRandomAnimal();
05:33 Auto Spawning – Use InvokeRepeating() inside Start()
07:10 Tuning Variables – Add startDelay + spawnInterval as public floats (Inspector controls)
08:33 Test Auto Spawn – Animals spawn every interval without pressing keys
09:10 Add Colliders to Animals – Open prefabs, add Box Collider, adjust bounds, enable Is Trigger
12:35 Projectile Setup – Pizza prefab: Box Collider + Is Trigger + Rigidbody (no gravity)
13:27 DetectCollisions Script – Create script using OnTriggerEnter(Collider other)
15:23 Apply to Prefabs – Add script to animals + Overrides → Apply All
16:31 Gameplay Tweaks – Reduce spawn range (30 → 20), delete scene animals, save
17:03 Fix Pizza Not Destroying – Add Destroy(other.gameObject);
18:20 Game Over Logic – In MoveForward, log "Game Over!" when animal crosses boundary
20:37 Wrap Up – Full loop working: spawn → shoot → collide → game over
Get free resources for this course from the below patreon link
/ 145923169
Welcome to Session 16 of the Unity 6.3 Junior Programmer Series (Deer Game Project)!
In this session, we upgrade our gameplay prototype by adding two must-have game features: automatic enemy spawning and real collision handling.
✅ What you’ll build in this tutorial:
Animals will spawn automatically every few seconds (no more pressing the S key)
You’ll create your first custom method: SpawnRandomAnimal()
You’ll use Unity’s InvokeRepeating() to spawn animals on a timer
You’ll add Box Colliders and enable Is Trigger on animals and the projectile
You’ll add a Rigidbody to the food projectile (pizza) and disable gravity
You’ll write a collision script using OnTriggerEnter()
When the pizza hits an animal, both objects get destroyed
If an animal reaches the other side without being hit, you’ll trigger a Game Over message using Debug.Log()
🎮 By the end of this session, your Deer Game will feel much more like a real game: unpredictable, time-based spawning, and proper hit detection!
📌 Project Files / Starter Download
If you don’t have the project from the previous session, you can download the starter project from the Patreon link shared in the video description / e-learning page:
16deergamecollisionsstart.zip (approx. 1GB)
🚀 Next Step Ideas (Coming Soon)
Add a real Game Over UI screen
Add score tracking when animals are destroyed
Add sound effects for hits and game over
Increase difficulty over time by reducing spawn interva