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Assets/Scripts/DisappearOnGround.cs

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+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class DisappearOnGround : MonoBehaviour
+{
+    [SerializeField] private float _disappearDelay = 0.5f;
+    [SerializeField] private float _disappearDuration = 1.5f;
+
+    private bool _isFading = false;
+
+    void OnCollisionEnter(Collision collision)
+    {
+        if (_isFading) return;
+        if (collision.gameObject.CompareTag("Ground"))
+            StartCoroutine(FadeAndDestroy());
+    }
+
+    IEnumerator FadeAndDestroy()
+    {
+        _isFading = true;
+        yield return new WaitForSeconds(_disappearDelay);
+
+        Renderer[] renderers = GetComponentsInChildren<Renderer>();
+
+        foreach (var r in renderers)
+        {
+            foreach (var mat in r.materials)
+            {
+                mat.SetFloat("_Mode", 2);
+                mat.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.SrcAlpha);
+                mat.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha);
+                mat.SetInt("_ZWrite", 0);
+                mat.DisableKeyword("_ALPHATEST_ON");
+                mat.EnableKeyword("_ALPHABLEND_ON");
+                mat.DisableKeyword("_ALPHAPREMULTIPLY_ON");
+                mat.renderQueue = 3000;
+            }
+        }
+
+        float t = 0f;
+        while (t < 1f)
+        {
+            t += Time.deltaTime / _disappearDuration;
+            foreach (var r in renderers)
+                foreach (var mat in r.materials)
+                {
+                    Color c = mat.color;
+                    c.a = Mathf.Lerp(1f, 0f, t);
+                    mat.color = c;
+                }
+            yield return null;
+        }
+
+        Destroy(gameObject);
+    }
+}