Casts a ray from the scene view camera and draws a line from transform to the hits. Can be used for selection in scene view.

RaycastPlacer.cs

#if UNITY_EDITOR

using System;
using System.Collections.Generic;
using Sirenix.OdinInspector;
using Sirenix.OdinInspector.Editor;
using UnityEditor;
using UnityEngine;
using System.Linq;
using Sirenix.Serialization;

public class RaycastPlacer : MonoBehaviour
{
    [Serializable]
    public class RaycastPlacerModel
    {
        [TitleGroup("Hit Objects")]
        [ShowInInspector]
        public RaycastHit raycastHit;
        
        [ShowInInspector, HideLabel, LabelWidth(0)] 
        public Transform HitTransform => raycastHit.transform;
        
//        [ShowInInspector]
        private GameObject HitGameObject => raycastHit.transform.gameObject;
        
        [ShowInInspector] 
        public Vector3 HitPoint => raycastHit.point;

        private Transform _transform;

        public RaycastPlacerModel(RaycastHit raycastHit, Transform transform)
        {
            this.raycastHit = raycastHit;
            _transform = transform;
            
        }

        [ButtonGroup, Button]
        public void AlignX()
        {
            var transformPosition = _transform.position;
            transformPosition.x = raycastHit.point.x;
            ChangeTransformPosition(transformPosition);
        }

        [ButtonGroup]
        public void AlignY()
        {
            var transformPosition = _transform.position;
            transformPosition.y = raycastHit.point.y;
            ChangeTransformPosition(transformPosition);

        }

        [ButtonGroup]
        public void AlignZ()
        {
            var transformPosition = _transform.position;
            transformPosition.z = raycastHit.point.z;
            ChangeTransformPosition(transformPosition);

        }

        [ButtonGroup]
        public void AlignXYZ()
        {
            ChangeTransformPosition(raycastHit.point);
        }

        public void ChangeTransformPosition(Vector3 transformPosition)
        {
            Undo.RecordObject(_transform, "Move Transform");
            _transform.position = transformPosition;
        }
        
        
        private Editor editor;

        [OnInspectorGUI]
        private void OnInspectorGUI()
        {
            if (editor == null || editor.target != HitGameObject)
            {
                editor = HitGameObject == null ? null : Editor.CreateEditor(HitGameObject);
            }

            Rect rect = GUILayoutUtility.GetRect(100, 100);
            editor?.DrawPreview(rect);
        }
    }

    
    [ShowInInspector]
    public static LayerMask raycastLayers = int.MaxValue;
    
    public float maxDistance = 100f;
    
    [HideInInspector]
    public bool isRaycasting;
    
    [OdinSerialize, ListDrawerSettings(HideAddButton = true, DraggableItems = false, ShowPaging = false), PropertyOrder(99)] 
    public List<RaycastPlacerModel> raycastHits = new List<RaycastPlacerModel>();
    
    private Ray mouseRay;
    
    
    [Button(ButtonSizes.Medium)]
    public void ToggleRaycasting() => isRaycasting = !isRaycasting;

    private void UpdateRaycast(SceneView sceneView)
    {
        Vector3 mousePosition = Event.current.mousePosition;
        mousePosition.y = SceneView.currentDrawingSceneView.camera.pixelHeight - mousePosition.y;
        mousePosition = SceneView.currentDrawingSceneView.camera.ScreenToWorldPoint(mousePosition);
        mousePosition.y = -mousePosition.y;
        
        mouseRay = HandleUtility.GUIPointToWorldRay(Event.current.mousePosition);
        raycastHits = Physics.RaycastAll(mouseRay, maxDistance)
            .Select(hit => new RaycastPlacerModel(hit, transform))
            .ToList();
        if (raycastHits.Count > 0)
        {
//            Debug.Log($"Hit {raycastHits.Count} objects.");
            DrawRays(transform.position, raycastHits);
        }

        SceneView.onSceneGUIDelegate -= UpdateRaycast;
    }
    
    private void DrawRays(Vector3 origin, List<RaycastPlacerModel> objects)
    {
        Handles.color = Color.magenta;
        foreach (var o in objects)
        {
            Handles.DrawLine(origin, o.raycastHit.point);

        }

    }
    
    
    private void OnDrawGizmosSelected()
    {
        if (isRaycasting == false) return;
        
        SceneView.onSceneGUIDelegate += UpdateRaycast;
        Gizmos.color = Color.yellow;
//        Debug.Log($"Ray: {mouseRay.origin} dir: {mouseRay.direction}");

    }
    
}


[CustomEditor(typeof(RaycastPlacer))]
class RaycastPlacerEditor : OdinEditor
{
    private void OnSceneGUI()
    {
        if (target is RaycastPlacer raycastPlacer)
        {
            // Retrieve the control Id
            int controlId = GUIUtility.GetControlID(FocusType.Passive);
            if (Event.current.type == EventType.MouseDown && Event.current.button == 0 && raycastPlacer.isRaycasting)
            {
                raycastPlacer.isRaycasting = false;
                // Tell the UI your event is the main one to use, it override the selection in  the scene view
                GUIUtility.hotControl = controlId;
                Event.current.Use();
//                Debug.Log("Event Used.");
            }
        }
    }
}

#endif