Assets\VFX\VisualEffectGraph-Extras\Editor\Utility\VFXEventTester\VFXEventTesterWindow.cs(17,16): error CS0246: The type or namespace name 'VisualEffect' could not be found (are you missing a using directive or an assembly reference?)

[arinssanghi]

using UnityEngine;
using UnityEngine.Experimental.VFX;
using UnityEditorInternal;
using System.Collections.Generic;

namespace UnityEditor.VFX.Utils
{
static class VFXEventTesterWindow
{
public static bool Visible;

    [SerializeField]
    static string m_CustomEvent = "CustomEvent";
    [SerializeField]
    static List<EventAttribute> m_Attributes;

    static VisualEffect m_Effect;
    static ReorderableList list;
    static readonly string PreferenceName = "VFXEventTester.Visible";

    static VFXEventTesterWindow()
    {
        m_Attributes = new List<EventAttribute>();

        Visible = EditorPrefs.GetBool(PreferenceName, false);

        list = new ReorderableList(m_Attributes, typeof(EventAttribute), true, true, true, true);
        list.drawHeaderCallback = drawHeader;
        list.drawElementCallback = drawItem;
        list.onAddDropdownCallback = drawAddDropDown;
    }

    [MenuItem("Edit/VisualEffect/Show Event Tester", validate = false, priority = 320)]
    static void ToggleVisibility()
    {
        Visible = !Visible;
        EditorPrefs.SetBool(PreferenceName, Visible);

        UpdateVisibility();
    }

    [MenuItem("Edit/Visual Effects/Show Event Tester", validate = true, priority = 320)]
    static bool CheckToggleVisibility()
    {
        Visible = EditorPrefs.GetBool(PreferenceName, Visible);
        Menu.SetChecked("Edit/Visual Effects/Show Event Tester", Visible);
        return true;
    }


    [InitializeOnLoadMethod]
    static void UpdateVisibility()
    {
        if (Visible)
            SceneView.onSceneGUIDelegate += DrawWindow;
        else
            SceneView.onSceneGUIDelegate -= DrawWindow;


    }

    private static void drawAddDropDown(Rect buttonRect, ReorderableList list)
    {
        GenericMenu menu = new GenericMenu();
        // Add Generic Attributes
        menu.AddItem(new GUIContent("Standard/Position"), false, AddVector3, "position");
        menu.AddItem(new GUIContent("Standard/Velocity"), false, AddVector3, "velocity");
        menu.AddItem(new GUIContent("Standard/Size"), false, AddFloat, "size");
        menu.AddItem(new GUIContent("Standard/Mass"), false, AddFloat, "mass");
        menu.AddItem(new GUIContent("Standard/Color"), false, AddColor, "color");
        menu.AddItem(new GUIContent("Standard/Alpha"), false, AddFloat, "alpha");
        menu.AddItem(new GUIContent("Standard/Age"), false, AddFloat, "age");
        menu.AddItem(new GUIContent("Standard/Lifetime"), false, AddFloat, "lifetime");
        menu.AddItem(new GUIContent("Standard/Alive"), false, AddBool, "alive");
        menu.AddItem(new GUIContent("Standard/Scale.X"), false, AddFloat, "scaleX");
        menu.AddItem(new GUIContent("Standard/Scale.Y"), false, AddFloat, "scaleY");
        menu.AddItem(new GUIContent("Standard/Scale.Z"), false, AddFloat, "scaleZ");
        menu.AddItem(new GUIContent("Standard/Angle.X"), false, AddFloat, "angleX");
        menu.AddItem(new GUIContent("Standard/Angle.Y"), false, AddFloat, "angleY");
        menu.AddItem(new GUIContent("Standard/Angle.Z"), false, AddFloat, "angleZ");
        // Add Advanced Attributes
        menu.AddItem(new GUIContent("Advanced/OldPosition"), false, AddVector3, "oldPosition");
        menu.AddItem(new GUIContent("Advanced/TargetPosition"), false, AddVector3, "targetPosition");
        menu.AddItem(new GUIContent("Advanced/Direction"), false, AddVector3, "direction");
        menu.AddItem(new GUIContent("Advanced/AngularVelocity.X"), false, AddFloat, "angularVelocityX");
        menu.AddItem(new GUIContent("Advanced/AngularVelocity.Y"), false, AddFloat, "angularVelocityY");
        menu.AddItem(new GUIContent("Advanced/AngularVelocity.Z"), false, AddFloat, "angularVelocityZ");
        // Add Generic Attributes
        menu.AddItem(new GUIContent("Custom/Custom bool"), false, AddBool, "customBool");
        menu.AddItem(new GUIContent("Custom/Custom Float"), false, AddFloat, "customFloat");
        menu.AddItem(new GUIContent("Custom/Custom Vector2"), false, AddVector2, "customVector2");
        menu.AddItem(new GUIContent("Custom/Custom Vector3"), false, AddVector3, "customVector3");
        menu.AddItem(new GUIContent("Custom/Custom Color"), false, AddColor, "customColor");

        // Add Custom Types
        menu.ShowAsContext();
    }

    static void AddFloat(object name)
    {
        m_Attributes.Add(new EventAttribute(name as string, EventAttributeType.Float, 0.0f));
    }

    static void AddBool(object name)
    {
        m_Attributes.Add(new EventAttribute(name as string, EventAttributeType.Bool, true));
    }

    static void AddVector2(object name)
    {
        m_Attributes.Add(new EventAttribute(name as string, EventAttributeType.Vector2, Vector2.zero));
    }

    static void AddVector3(object name)
    {
        m_Attributes.Add(new EventAttribute(name as string, EventAttributeType.Vector3, Vector3.zero));
    }

    static void AddColor(object name)
    {
        m_Attributes.Add(new EventAttribute(name as string, EventAttributeType.Color, Color.white));
    }



    static void DrawWindow(SceneView sceneView)
    {
        if (Selection.activeGameObject != null)
        {
            var component = Selection.activeGameObject.GetComponent<VisualEffect>();
            if (component != null)
            {
                m_Effect = component;
                SceneViewOverlay.Window(Contents.title, WindowFunction, 601, SceneViewOverlay.WindowDisplayOption.OneWindowPerTitle);
            }
            else
            {
                m_Effect = null;
            }
        }
    }

    static void WindowFunction(UnityEngine.Object target, SceneView sceneView)
    {
        WindowGUI();
    }

    [System.Serializable]
    enum EventAttributeType
    {
        Float = 0,
        Vector2 = 1,
        Vector3 = 2,
        Color = 3,
        Bool = 4
    }

    [System.Serializable]
    class EventAttribute
    {
        public string name;
        public EventAttributeType type;
        public object value;

        public EventAttribute()
        {
            name = "Attribute";
            type = EventAttributeType.Float;
            value = 0.0f;
        }

        public EventAttribute(string name, EventAttributeType type, object value)
        {
            this.name = name;
            this.type = type;
            this.value = value;
        }
    }

    private static void drawHeader(Rect rect)
    {
        GUI.Label(rect, "Event Attributes");
    }

    static void drawItem(Rect rect, int index, bool isActive, bool isFocused)
    {
        if (m_Attributes[index] == null)
        {
            var color = GUI.color;
            GUI.color = Color.red;
            EditorGUI.LabelField(rect, "NULL OR DELETED");
            GUI.color = color;
            return;
        }

        rect.yMin += 2;
        rect.height = 16;

        var namerect = rect;
        namerect.width = 100;

        m_Attributes[index].name = GUI.TextField(namerect, m_Attributes[index].name);

        var typerect = rect;
        typerect.xMin = rect.xMin + 108;
        typerect.width = 64;
        m_Attributes[index].type = (EventAttributeType)EditorGUI.EnumPopup(typerect, m_Attributes[index].type);

        var valueRect = rect;
        valueRect.xMin = rect.xMin + 180;
        switch (m_Attributes[index].type)
        {
            case EventAttributeType.Bool:
                if (m_Attributes[index].value == null || !(m_Attributes[index].value is bool))
                    m_Attributes[index].value = true;

                m_Attributes[index].value = (bool)EditorGUI.Toggle(valueRect, (bool)m_Attributes[index].value);
                break;

            case EventAttributeType.Float:
                if (m_Attributes[index].value == null || !(m_Attributes[index].value is float))
                    m_Attributes[index].value = 1.0f;

                m_Attributes[index].value = (float)EditorGUI.FloatField(valueRect, (float)m_Attributes[index].value);
                break;

            case EventAttributeType.Vector2:
                if (m_Attributes[index].value == null || !(m_Attributes[index].value is Vector2))
                    m_Attributes[index].value = Vector2.zero;

                m_Attributes[index].value = (Vector2)EditorGUI.Vector2Field(valueRect, "", (Vector2)m_Attributes[index].value);
                break;

            case EventAttributeType.Vector3:
                if (m_Attributes[index].value == null || !(m_Attributes[index].value is Vector3))
                    m_Attributes[index].value = Vector3.zero;

                m_Attributes[index].value = (Vector3)EditorGUI.Vector3Field(valueRect, "", (Vector3)m_Attributes[index].value);
                break;

            case EventAttributeType.Color:
                if (m_Attributes[index].value == null || !(m_Attributes[index].value is Color))
                    m_Attributes[index].value = Color.white;

                m_Attributes[index].value = (Color)EditorGUI.ColorField(valueRect, (Color)m_Attributes[index].value);
                break;
        }
    }

    static void WindowGUI()
    {
        EditorGUI.BeginDisabled(m_Effect == null);
        EditorGUILayout.Space();
        list.DoLayoutList();
        EditorGUILayout.Space();
        using (new GUILayout.HorizontalScope(GUILayout.Width(360)))
        {
            if (GUILayout.Button("Play", Styles.leftButton, GUILayout.Height(24)))
            {
                SendEvent("OnPlay");
            }
            if (GUILayout.Button("Stop", Styles.middleButton, GUILayout.Height(24)))
            {
                SendEvent("OnStop");
            }
            if (GUILayout.Button("Custom", Styles.rightButton, GUILayout.Height(24)))
            {
                SendEvent(m_CustomEvent);
            }
        }
        m_CustomEvent = EditorGUILayout.TextField("Custom Event", m_CustomEvent);
        EditorGUI.EndDisabled();
    }

    static void SendEvent(string name)
    {
        if (m_Effect == null) return;
        var attrib = m_Effect.CreateVFXEventAttribute();

        // set all attributes
        foreach (var attribute in m_Attributes)
        {
            if (attribute == null) continue;
            switch (attribute.type)
            {
                case EventAttributeType.Bool: attrib.SetBool(attribute.name, (bool)attribute.value); break;
                case EventAttributeType.Float: attrib.SetFloat(attribute.name, (float)attribute.value); break;
                case EventAttributeType.Vector2: attrib.SetVector2(attribute.name, (Vector2)attribute.value); break;
                case EventAttributeType.Vector3: attrib.SetVector3(attribute.name, (Vector3)attribute.value); break;
                case EventAttributeType.Color: attrib.SetVector4(attribute.name, (Color)attribute.value); break;
            }
        }

        // then send event with attributes
        if (name == "OnPlay")
            m_Effect.Play(attrib);
        else if (name == "OnStop")
            m_Effect.Stop(attrib);
        else
            m_Effect.SendEvent(name, attrib);

    }

    static class Contents
    {
        public static readonly GUIContent title = new GUIContent("VFX Event Tester");
    }

    static class Styles
    {
        public static GUIStyle leftButton;
        public static GUIStyle middleButton;
        public static GUIStyle rightButton;

        static Styles()
        {
            leftButton = new GUIStyle(EditorStyles.miniButtonLeft);
            middleButton = new GUIStyle(EditorStyles.miniButtonMid);
            rightButton = new GUIStyle(EditorStyles.miniButtonRight);
            leftButton.fontSize = 12;
            middleButton.fontSize = 12;
            rightButton.fontSize = 12;
        }
    }

}

}

[s1099]

Please Update all the packages and then try again.

Are you using Unity Version 2018.3.8f1 ???

[LunarFuror]

I'm having the same issue and finding no answers. I'm on Unity 2020.1.6.f1

[s1099]

Install vfx graph package

[GeorgTsabou]

Just change the "using UnityEngine.Experimental.VFX;" to "using UnityEngine.VFX;" and it should work fine.