Unity Skill

Unity integration for SPT (Single Player Tarkov) modding via BepInEx plugins. This project uses Unity 2021.x APIs through decompiled EFT assemblies, with heavy reliance on Physics.OverlapSphere, NavMesh, Vector3 math, and coroutine-based async patterns. All Unity calls happen on the main thread; use UnityMainThreadDispatcher patterns when needed.

Quick Start

NavMesh Position Validation

using UnityEngine;
using UnityEngine.AI;

// ALWAYS validate positions before navigation
public bool TryGetValidNavMeshPosition(Vector3 target, out Vector3 validPosition, float maxDistance = 2f)
{
    if (NavMesh.SamplePosition(target, out NavMeshHit hit, maxDistance, NavMesh.AllAreas))
    {
        validPosition = hit.position;
        return true;
    }
    validPosition = Vector3.zero;
    return false;
}

Physics Overlap for Detection

// Find lootable objects within radius
private readonly Collider[] _scanBuffer = new Collider[64];

public void ScanForLoot(Vector3 position, float radius, int layerMask)
{
    int count = Physics.OverlapSphereNonAlloc(position, radius, _scanBuffer, layerMask);
    for (int i = 0; i < count; i++)
    {
        var collider = _scanBuffer[i];
        // Process collider.gameObject
    }
}

Distance and Direction Calculations

// Prefer sqrMagnitude for distance comparisons (avoids sqrt)
float distanceSq = (targetPos - botPos).sqrMagnitude;
if (distanceSq < maxDistanceSq) // Compare squared values
{
    Vector3 direction = (targetPos - botPos).normalized;
    // Use direction for facing/movement
}

Key Concepts

Concept	Usage	Example
NavMesh sampling	Validate movement targets	NavMesh.SamplePosition(pos, out hit, 2f, NavMesh.AllAreas)
Physics overlap	Area detection	Physics.OverlapSphereNonAlloc(pos, radius, buffer, mask)
Layer masks	Filter physics queries	LayerMask.GetMask("Loot", "Interactive")
Transform caching	Performance	private Transform _cachedTransform;
Vector3 math	Distance/direction	(a - b).sqrMagnitude, (a - b).normalized

Common Patterns

Spawn Position Calculation

When: Spawning MedicBuddy team behind player

public Vector3 CalculateSpawnPosition(Transform playerTransform, float distance = 15f)
{
    // Spawn behind and slightly offset
    Vector3 behindPlayer = playerTransform.position - playerTransform.forward * distance;
    
    if (TryGetValidNavMeshPosition(behindPlayer, out Vector3 validPos))
        return validPos;
    
    // Fallback: try sides
    Vector3 leftPos = playerTransform.position - playerTransform.right * distance;
    if (TryGetValidNavMeshPosition(leftPos, out validPos))
        return validPos;
        
    return playerTransform.position; // Last resort
}

Coroutine for Timed Operations

When: Healing ticks, delayed actions

private IEnumerator HealOverTime(float totalAmount, float duration)
{
    float elapsed = 0f;
    float healPerSecond = totalAmount / duration;
    
    while (elapsed < duration)
    {
        ApplyHealing(healPerSecond * Time.deltaTime);
        elapsed += Time.deltaTime;
        yield return null; // Wait one frame
    }
}

See Also

• patterns - GameObject handling, physics queries, NavMesh
• workflows - Common Unity workflows in SPT modding

Related Skills

• See the csharp skill for C# patterns and error handling
• See the bepinex skill for plugin lifecycle and Unity integration
• See the harmony skill for patching Unity methods