04.07.2022

Heli_with_panels/Assets/Editor/SetPivot.cs

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+using UnityEngine;
+using UnityEditor;
+
+public class SetPivot : EditorWindow
+{
+
+    Vector3 p; //Pivot value -1..1, calculated from Mesh bounds
+    Vector3 last_p; //Last used pivot
+
+    GameObject obj; //Selected object in the Hierarchy
+    MeshFilter meshFilter; //Mesh Filter of the selected object
+    Mesh mesh; //Mesh of the selected object
+    Collider col; //Collider of the selected object
+
+    bool pivotUnchanged; //Flag to decide when to instantiate a copy of the mesh
+
+    [MenuItem("GameObject/Set Pivot")] //Place the Set Pivot menu item in the GameObject menu
+    static void Init()
+    {
+        SetPivot window = (SetPivot)EditorWindow.GetWindow(typeof(SetPivot));
+        window.RecognizeSelectedObject(); //Initialize the variables by calling RecognizeSelectedObject on the class instance
+        window.Show();
+    }
+
+    void OnGUI()
+    {
+        if (obj)
+        {
+            if (mesh)
+            {
+                p.x = EditorGUILayout.Slider("X", p.x, -11.0f, 11.0f);
+                p.y = EditorGUILayout.Slider("Y", p.y, -1.0f, 1.0f);
+                p.z = EditorGUILayout.Slider("Z", p.z, -1.0f, 1.0f);
+                if (p != last_p)
+                { //Detects user input on any of the three sliders
+                  //Only create instance of mesh when user changes pivot
+                    if (pivotUnchanged) mesh = meshFilter.sharedMesh; pivotUnchanged = false;
+                    UpdatePivot();
+                    last_p = p;
+                }
+                if (GUILayout.Button("Center"))
+                { //Set pivot to the center of the mesh bounds
+                  //Only create instance of mesh when user changes pivot
+                    if (pivotUnchanged) mesh = meshFilter.sharedMesh; pivotUnchanged = false;
+                    p = Vector3.zero;
+                    UpdatePivot();
+                    last_p = p;
+                }
+                GUILayout.Label("Bounds " + mesh.bounds.ToString());
+            }
+            else
+            {
+                GUILayout.Label("Selected object does not have a Mesh specified.");
+            }
+        }
+        else
+        {
+            GUILayout.Label("No object selected in Hierarchy.");
+        }
+    }
+
+    //Achieve the movement of the pivot by moving the transform position in the specified direction
+    //and then moving all vertices of the mesh in the opposite direction back to where they were in world-space
+    void UpdatePivot()
+    {
+        Vector3 diff = Vector3.Scale(mesh.bounds.extents, last_p - p); //Calculate difference in 3d position
+        obj.transform.position -= Vector3.Scale(diff, obj.transform.localScale); //Move object position
+                                                                                 //Iterate over all vertices and move them in the opposite direction of the object position movement
+        Vector3[] verts = mesh.vertices;
+        for (int i = 0; i < verts.Length; i++)
+        {
+            verts[i] += diff;
+        }
+        mesh.vertices = verts; //Assign the vertex array back to the mesh
+        mesh.RecalculateBounds(); //Recalculate bounds of the mesh, for the renderer's sake
+                                  //The 'center' parameter of certain colliders needs to be adjusted
+                                  //when the transform position is modified
+        if (col)
+        {
+            if (col is BoxCollider)
+            {
+                ((BoxCollider)col).center += diff;
+            }
+            else if (col is CapsuleCollider)
+            {
+                ((CapsuleCollider)col).center += diff;
+            }
+            else if (col is SphereCollider)
+            {
+                ((SphereCollider)col).center += diff;
+            }
+        }
+    }
+
+    //Look at the object's transform position in comparison to the center of its mesh bounds
+    //and calculate the pivot values for xyz
+    void UpdatePivotVector()
+    {
+        Bounds b = mesh.bounds;
+        Vector3 offset = -1 * b.center;
+        p = last_p = new Vector3(offset.x / b.extents.x, offset.y / b.extents.y, offset.z / b.extents.z);
+    }
+
+    //When a selection change notification is received
+    //recalculate the variables and references for the new object
+    void OnSelectionChange()
+    {
+        RecognizeSelectedObject();
+    }
+
+    //Gather references for the selected object and its components
+    //and update the pivot vector if the object has a Mesh specified
+    void RecognizeSelectedObject()
+    {
+        Transform t = Selection.activeTransform;
+        obj = t ? t.gameObject : null;
+        if (obj)
+        {
+            meshFilter = obj.GetComponent(typeof(MeshFilter)) as MeshFilter;
+            mesh = meshFilter ? meshFilter.sharedMesh : null;
+            if (mesh)
+                UpdatePivotVector();
+            col = obj.GetComponent(typeof(Collider)) as Collider;
+            pivotUnchanged = true;
+        }
+        else
+        {
+            mesh = null;
+        }
+    }
+}

Heli_with_panels/Assets/Editor/SetPivot.cs.meta

@@ -0,0 +1,11 @@
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