## Collision Detection Mechanism in BoxCollider

The BoxCollider class exemplifies an adept collision detection system within the CPI311 game engine, particularly tailored for interactions with SphereCollider. By leveraging static arrays to define essential geometric properties, such as normals, vertices, and indices, the class efficiently implements the separating axis theorem. Its Collides method meticulously scrutinizes potential collisions on each face and triangle, ensuring accurate spatial interactions. For those seeking assistance with game development or grappling with a C# assignment, understanding this well-constructed collision detection mechanism could prove invaluable. If you're looking for assistance with your C# assignment or need guidance in game development, the BoxCollider class serves as a robust foundation, showcasing practical implementation of collision detection principles and potentially providing clarity and support for individuals working on C# assignments related to game development.

## Block 1: Namespace and Class Declaration

```
namespace CPI311.GameEngine
{
public class BoxCollider : Collider
{
// Class implementation...
}
}
```

This block starts with the declaration of the namespace CPI311.GameEngine and defines a class named BoxCollider that extends the Collider class.

## Block 2: Properties and Static Arrays

```
public float Size { get; set; }
private static Vector3[] normals = { /* ... */ };
private static Vector3[] vertices = { /* ... */ };
private static int[] indices = { /* ... */ };
```

This block contains properties and static arrays used to define the box geometry. Size is a property representing the size of the box. The arrays normals, vertices, and indices define the normals, vertices, and indices of the box's six faces, respectively.

## Block 3: Collides Method

```
public override bool Collides(Collider other, out Vector3 normal)
{
// Method implementation...
}
```

This method overrides the Collides method from the base class Collider. It checks for collisions between the current BoxCollider and another Collider, specifically handling collisions with a SphereCollider. It returns a boolean indicating whether a collision occurred and an output parameter normal representing the collision normal.

## Block 4: SphereCollider Collision Detection

```
if (other is SphereCollider)
{
// Collision detection with SphereCollider...
}
```

This block checks if the other collider is of type SphereCollider. If true, it proceeds with collision detection specific to a sphere, utilizing the Separating Axis Theorem.

## Block 5: Collision Detection Loop

```
for (int i = 0; i < 6; i++)
{
for (int j = 0; j < 2; j++)
{
// Loop body...
}
}
```

This nested loop iterates through the faces of the box and its two triangles. It performs collision detection for each triangle of each face.

## Block 6: Triangle and Plane Intersection

```
Vector3 a = vertices[indices[baseIndex]] * Size;
Vector3 b = vertices[indices[baseIndex + 1]] * Size;
Vector3 c = vertices[indices[baseIndex + 2]] * Size;
Vector3 n = normals[i];
Vector3 p = collider.Transform.Position;
float d = Math.Abs(Vector3.Dot(p - a, n));
```

This block defines variables representing the vertices of the triangle and the normal of the face. It calculates the distance d from the sphere's center to the plane of the triangle.

## Block 7: Point Inside Triangle Check

```
if (d < collider.Radius)
{
Vector3 q = p - n * d;
float area1 = Vector3.Dot(Vector3.Cross(b - a, q - a), n);
float area2 = Vector3.Dot(Vector3.Cross(c - b, q - b), n);
float area3 = Vector3.Dot(Vector3.Cross(a - c, q - c));
if (!(area1 < 0 || area2 < 0 || area3 < 0))
{
// Collision detected...
}
}
```

If the sphere is close enough to the plane, it calculates the closest point q on the plane to the sphere. It then checks if this point is inside the triangle using barycentric coordinates.

## Block 8: Collision Response

```
normal += n;
j = 1;
if (i % 2 == 0) i += 1;
isColliding = true;
```

If a collision is detected, it updates the accumulated normal, skips the second triangle if necessary, and skips the opposite side if necessary. The isColliding flag is set to true.

## Block 9: Normalization and Return

```
normal.Normalize();
return isColliding;
```

Finally, the accumulated normal is normalized, and the method returns whether a collision occurred. If a collision occurred, the normalized normal indicates the direction of the collision response. If not, the normal is (0, 0, 0).

## Conclusion

In conclusion, delving into the intricacies of the BoxCollider class unveils a robust collision detection system crucial for immersive C# game development. This comprehensive exploration not only enhances your understanding of spatial interactions and the separating axis theorem but also serves as a valuable resource for navigating programming assignments. Whether you're a student seeking clarity or a game developer aiming to optimize collision algorithms, the insights gained from dissecting this class empower you with practical knowledge. As you embark on your journey in C# game development, leverage this guide on the BoxCollider class to navigate challenges and elevate your programming skills to new heights.