TrailRenderer

Description

Creates a visual trail of polygons that follows a GameObject's movement, useful for emphasizing motion or creating dynamic visual effects.

Use the Trail Renderer to tie an effect to a moving GameObject’s position. Trail Renderers help create visual effects such as missile trails, weapon swing arcs, or highlighting the path of fast-moving objects. They provide a dynamic way to visually emphasize motion, making them useful for effects in action-oriented games or scenes with rapid object movement.

The component works by storing the GameObject’s position at intervals defined by the TrailRenderer.minVertexDistance property and connecting these points to form a continuous ribbon-like trail. You can control the duration of the trail using the TrailRenderer.time property, and you can configure its appearance, including width and color gradients, using a Material.

To control the trail effect, use the TrailRenderer.Clear method. This method instantly removes any existing trail segments and prevents the Trail Renderer from adding new points.

Additional resources: Transform, Material, LineRenderer, TrailRenderer.Clear.

The following code sample demonstrates how to attach a Trail Renderer to a moving GameObject and configure some of its basic properties. Attach this script to an empty GameObject in your scene.

// Ensure the GameObject has a TrailRenderer component
using UnityEngine;

[RequireComponent(typeof(TrailRenderer))]
public class SimpleTrail : MonoBehaviour
{
    public float moveSpeed = 3.0f;
    public float circleRadius = 2.0f;

    private TrailRenderer trail;
    private float angle = 0f;

    void Start()
    {
        trail = GetComponent<TrailRenderer>();

        // Configure the trail's appearance
        trail.time = 1.5f;              // How long the trail lasts in seconds
        trail.startWidth = 0.3f;        // Width at the newest part of the trail
        trail.endWidth = 0f;            // Width at the oldest part of the trail

        // Set a color gradient (e.g., white fading to transparent red)
        Gradient gradient = new Gradient();
        gradient.SetKeys(
           // Color keys: White at the start, Red at the end
           new GradientColorKey[] { new GradientColorKey(Color.white, 0.0f), new GradientColorKey(Color.red, 1.0f) },
           // Alpha keys: Opaque at the start, Transparent at the end
           new GradientAlphaKey[] { new GradientAlphaKey(1.0f, 0.0f), new GradientAlphaKey(0.0f, 1.0f) }
        );
        trail.colorGradient = gradient;
        
        GameObject head = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        Transform headTransform = head.GetComponent<Transform>();
        headTransform.SetParent(transform);
        headTransform.localPosition = Vector3.zero;
        headTransform.localScale = Vector3.one * 0.2f; 
    }

    void Update()
    {
        // Move the GameObject in a circle
        angle += moveSpeed * Time.deltaTime;
        float x = Mathf.Cos(angle) * circleRadius;
        float z = Mathf.Sin(angle) * circleRadius;
        transform.position = new Vector3(x, 0, z);
    }
}

Properties

Public Methods

Inherited Members