Challenge 4: Collision log
- Game Development course
- Beginner
- Lesson 82/83
- 5 min
Write a C# script that reports collisions with OnCollisionEnter.
Challenge 4: Collision report
In the physics engine, when two solid Colliders make contact, the OnCollisionEnter callback fires. This method delivers colliding object name, contact points, and velocity data via the Collision parameter.
void OnCollisionEnter(Collision collision) {
Debug.Log("Collided with: " + collision.gameObject.name);
}Enemy impacts, bullet strikes, or wall collisions trigger their respective gameplay feedback routines inside this function.
Practice Print collided obstacle
Assign "Obstacle" to the obstacle variable and print Collision: Obstacle to the console.
Starter code
using System;
class Program
{
static void Main()
{
// obstacle değişkenini tanımlayıp çarpışmayı yazdır
}
}Sample solution
using System;
class Program
{
static void Main()
{
string obstacle = "Obstacle";
Console.WriteLine("Collision: " + obstacle);
}
}Expected output
Collision: Obstacle
Practice Print target and obstacle type
Assign "Spike" to target and "Hazard" to type. Print Hit: Spike | Type: Hazard to the console.
Starter code
using System;
class Program
{
static void Main()
{
// target ve type değerlerini tanımlayıp yazdır
}
}Sample solution
using System;
class Program
{
static void Main()
{
string target = "Spike";
string type = "Hazard";
Console.WriteLine("Hit: " + target + " | Type: " + type);
}
}Expected output
Hit: Spike | Type: Hazard
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What type of information is contained inside the Collision parameter passed by Unity into OnCollisionEnter?
- The collided object, contact points, and impact velocity Correct answer
- Only the instantaneous temperature and memory of the GPU
- The aggregate playback duration of all project audio files
- Only the current frames-per-second (FPS) count of the game
Explanation: The Collision object encapsulates comprehensive physics data including hit GameObject, surfaces, and impact velocities.
2 Specify collision parameter type
void OnCollisionEnter(____ collision)void OnCollisionEnter(Collision collision)Explanation: The OnCollisionEnter method accepts collision data as a parameter of type Collision.
3 Collision report elements
| Term | Meaning |
|---|---|
OnCollisionEnter |
Physics method on first object contact |
Collision |
Holds contact & colliding object data |
gameObject.name |
Name shown in Hierarchy panel |
Debug.Log |
Logs collision notification to console |