Add 'True Origin' placement mode

CHANGES.md

@@ -9,6 +9,7 @@
 ##### Additions :tada:
 
 - Editor builds for macOS now target macOS 10.15+. Previously, macOS 12.7+ was required.
+- Added `originPlacement` property to `CesiumGeoreference` to toggle between "Cartographic Origin" and "True Origin" reference modes. Whereas "Cartographic Origin" is the default for georeferenced tilesets, "True Origin" may be used for non-georeferenced tilesets centered at the origin.
 
 ##### Fixes :wrench:
 

Editor/CesiumGeoreferenceEditor.cs

@@ -8,6 +8,19 @@ public class CesiumGeoreferenceEditor : Editor
     {
         private CesiumGeoreference _georeference;
 
+        private SerializedProperty _originPlacement;
+
+        // Converts the SerializedProperty's value to the CesiumGeoreferenceOriginPlacement
+        // enum it corresponds to, for convenience.
+        internal CesiumGeoreferenceOriginPlacement originPlacement
+        {
+            get
+            {
+                return (CesiumGeoreferenceOriginPlacement)
+                    this._originPlacement.enumValueIndex;
+            }
+        }
+
         private SerializedProperty _originAuthority;
 
         // Converts the SerializedProperty's value to the CesiumGeoreferenceOriginAuthority
@@ -37,6 +50,8 @@ private void OnEnable()
             this._georeference = (CesiumGeoreference)this.target;
 
             this._ellipsoidOverride = this.serializedObject.FindProperty("_ellipsoidOverride");
+            this._originPlacement =
+                this.serializedObject.FindProperty("_originPlacement");
             this._originAuthority =
                 this.serializedObject.FindProperty("_originAuthority");
 
@@ -58,15 +73,16 @@ public override void OnInspectorGUI()
             DrawInspectorButtons();
             EditorGUILayout.Space(5);
 
-            this.DrawEllipsoidOverrideProperty();
-            EditorGUILayout.Space(5);
-            this.DrawScaleProperty();
-            EditorGUILayout.Space(5);
+            this.DrawOriginPlacementProperty();
             this.DrawOriginAuthorityProperty();
             EditorGUILayout.Space(5);
             this.DrawLongitudeLatitudeHeightProperties();
             EditorGUILayout.Space(5);
             this.DrawEarthCenteredEarthFixedProperties();
+            EditorGUILayout.Space(5);
+            this.DrawScaleProperty();
+            EditorGUILayout.Space(5);
+            this.DrawEllipsoidOverrideProperty();
 
             this.serializedObject.ApplyModifiedProperties();
         }
@@ -93,35 +109,62 @@ private void DrawInspectorButtons()
                 CesiumEditorUtility.PlaceGeoreferenceAtCameraPosition(this._georeference);
             }
 
+            EditorGUI.BeginDisabledGroup(
+                this.originPlacement != CesiumGeoreferenceOriginPlacement.CartographicOrigin);
             GUIContent createSubSceneContent = new GUIContent(
                 "Create Sub-Scene Here",
                 "Creates a child GameObject with a \"CesiumSubScene\" component whose origin " +
                 "is set to the camera's current location. A \"CesiumSubScene\" describes a " +
                 "corresponding world location that can be jumped to, and only one sub-scene " +
-                "can be worked on in the editor at a time.");
+                "can be worked on in the editor at a time." +
+                "\n\n" +
+                "This is disabled when \"Origin Placement\" is set to \"True Origin\".");
             if (GUILayout.Button("Create Sub-Scene Here"))
             {
                 CesiumEditorUtility.CreateSubScene(this._georeference);
             }
+            EditorGUI.EndDisabledGroup();
+
             GUILayout.EndHorizontal();
 
             EditorGUI.EndDisabledGroup();
         }
 
+        private void DrawOriginPlacementProperty()
+        {
+            GUIContent originPlacementContent = new GUIContent(
+                "Origin Placement",
+                "The placement of this GameObject's origin (0,0,0) within the tileset." +
+                "\n\n" +
+                "3D Tiles tilesets often use Earth-centered, Earth-fixed coordinates, such that " +
+                "the tileset content is in a small bounding volume 6-7 million meters " +
+                "(the radius of the Earth) away from the coordinate system origin. This property " +
+                "allows an alternative position, other than the tileset's true origin, to be " +
+                "treated as the origin for the purpose of this GameObject. Using this property will " +
+                "preserve vertex precision (and thus avoid jittering) much better than setting the " +
+                "GameObject's Transform property.");
+            EditorGUILayout.PropertyField(this._originPlacement, originPlacementContent);
+        }
+
         private void DrawEllipsoidOverrideProperty()
         {
+            EditorGUI.BeginDisabledGroup(
+                this.originPlacement != CesiumGeoreferenceOriginPlacement.CartographicOrigin);
+
             GUIContent ellipsoidOverrideContent = new GUIContent(
                 "Ellipsoid Override",
                 "The ellipsoid definition to use for this tileset. If this is left blank, " +
                 "the ellipsoid specified by the tileset is used, or WGS84 if the tileset " +
                 "doesn't list an ellipsoid to use.");
             EditorGUI.BeginChangeCheck();
             EditorGUILayout.PropertyField(this._ellipsoidOverride, ellipsoidOverrideContent);
-            if(EditorGUI.EndChangeCheck())
+            if (EditorGUI.EndChangeCheck())
             {
                 this.serializedObject.ApplyModifiedProperties();
                 this._georeference.ReloadEllipsoid();
             }
+
+            EditorGUI.EndDisabledGroup();
         }
 
         private void DrawScaleProperty()
@@ -137,17 +180,24 @@ private void DrawScaleProperty()
 
         private void DrawOriginAuthorityProperty()
         {
+            EditorGUI.BeginDisabledGroup(
+                this.originPlacement != CesiumGeoreferenceOriginPlacement.CartographicOrigin);
+
             GUIContent originAuthorityContent = new GUIContent(
                 "Origin Authority",
                 "The set of coordinates that authoritatively define the origin of " +
                 "this georeference.");
             EditorGUILayout.PropertyField(this._originAuthority, originAuthorityContent);
+
+            EditorGUI.EndDisabledGroup();
         }
 
         private void DrawLongitudeLatitudeHeightProperties()
         {
+            CesiumGeoreferenceOriginPlacement placement = this.originPlacement;
             CesiumGeoreferenceOriginAuthority authority = this.originAuthority;
             EditorGUI.BeginDisabledGroup(
+                placement != CesiumGeoreferenceOriginPlacement.CartographicOrigin ||
                 authority != CesiumGeoreferenceOriginAuthority.LongitudeLatitudeHeight);
 
             GUILayout.Label(
@@ -187,8 +237,10 @@ private void DrawLongitudeLatitudeHeightProperties()
 
         private void DrawEarthCenteredEarthFixedProperties()
         {
+            CesiumGeoreferenceOriginPlacement placement = this.originPlacement;
             CesiumGeoreferenceOriginAuthority authority = this.originAuthority;
             EditorGUI.BeginDisabledGroup(
+                placement != CesiumGeoreferenceOriginPlacement.CartographicOrigin ||
                  authority != CesiumGeoreferenceOriginAuthority.EarthCenteredEarthFixed);
 
             GUILayout.Label(

Runtime/CesiumGeoreference.cs

@@ -6,6 +6,30 @@
 
 namespace CesiumForUnity
 {
+    /// <summary>
+    /// An enumeration of the possible strategies for placing the origin of a <see cref="CesiumGeoreference"/>.
+    /// </summary>
+    public enum CesiumGeoreferenceOriginPlacement
+    {
+        /// <summary>
+        /// Use the tileset's true origin as the GameObject's origin.
+        /// </summary>
+        /// <remarks>
+        /// For georeferenced tilesets, this usually means the GameObject's origin will be
+        /// at the center of the Earth, which is not recommended. For a non-georeferenced 
+        /// tileset, however, such as a detailed building with a local origin, putting the
+        /// GameObject's origin at the same location as the tileset's origin can be useful.
+        /// </remarks>
+        TrueOrigin,
+        /// <summary>
+        /// Use a custom position within the tileset as the GameObject's origin. The 
+        /// position is expressed as cartographic coordinates determined by the 
+        /// <see cref="CesiumGeoreference.originAuthority"/>, and that position within
+        /// the tileset will be at coordinate (0,0,0) in the GameObject's coordinate system.
+        /// </summary>
+        CartographicOrigin
+    }
+
     /// <summary>
     /// Identifies the set of the coordinates that authoritatively define
     /// the origin of a <see cref="CesiumGeoreference"/>.
@@ -68,6 +92,9 @@ public partial class CesiumGeoreference : MonoBehaviour
         [SerializeField]
         private CesiumEllipsoid _ellipsoidOverride = null;
 
+        [SerializeField]
+        private CesiumGeoreferenceOriginPlacement _originPlacement = CesiumGeoreferenceOriginPlacement.CartographicOrigin;
+
         [SerializeField]
         private CesiumGeoreferenceOriginAuthority _originAuthority = CesiumGeoreferenceOriginAuthority.LongitudeLatitudeHeight;
 
@@ -113,26 +140,55 @@ public partial class CesiumGeoreference : MonoBehaviour
 
         #endregion
 
+        /// <summary>
+        /// The placement of this GameObject's origin (coordinate 0,0,0) within the tileset.
+        /// </summary>
+        /// <remarks>
+        /// 3D Tiles tilesets often use Earth-centered, Earth-fixed coordinates, such
+        /// that the tileset content is in a small bounding volume 6-7 million meters
+        /// (the radius of the Earth) away from the coordinate system origin. This
+        /// property allows an alternative position, other than the tileset's true
+        /// origin, to be treated as the origin for the purpose of this GameObject. Using
+        /// this property will preserve vertex precision (and thus avoid jittering)
+        /// much better than setting the GameObject's Transform property.
+        /// </remarks>
+        public CesiumGeoreferenceOriginPlacement originPlacement
+        {
+            get => this._originPlacement;
+            set
+            {
+                this._originPlacement = value;
+                this.MoveOrigin();
+            }
+        }
+
         /// <summary>
         /// Identifies which set of coordinates authoritatively defines the origin
         /// of this georeference.
         /// </summary>
+        /// <remarks>
+        /// Setting this property changes the <see cref="originPlacement"/> accordingly.
+        /// </remarks>
         public CesiumGeoreferenceOriginAuthority originAuthority
         {
             get => this._originAuthority;
             set
             {
                 this._originAuthority = value;
-                this.MoveOrigin();
+                this.originPlacement = CesiumGeoreferenceOriginPlacement.CartographicOrigin;
             }
         }
 
         /// <summary>
         /// The latitude of the origin of the coordinate system, in degrees, in the range -90 to 90.
-        /// This property is ignored unless <see cref="originAuthority"/> is
+        /// </summary>
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.LongitudeLatitudeHeight"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double latitude
         {
             get => this._latitude;
@@ -145,10 +201,14 @@ public double latitude
 
         /// <summary>
         /// The longitude of the origin of the coordinate system, in degrees, in the range -180 to 180.
-        /// This property is ignored unless <see cref="originAuthority"/> is
+        /// </summary>
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.LongitudeLatitudeHeight"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double longitude
         {
             get => this._longitude;
@@ -162,11 +222,15 @@ public double longitude
         /// <summary>
         /// The height in the origin of the coordinate system, in meters above the ellipsoid. Do not
         /// confuse this with a geoid height or height above mean sea level, which can be tens of
-        /// meters higher or lower depending on where in the world the object is located. This
-        /// property is ignored unless <see cref="originAuthority"/> is
+        /// meters higher or lower depending on where in the world the object is located.
+        /// </summary>
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.LongitudeLatitudeHeight"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double height
         {
             get => this._height;
@@ -179,10 +243,14 @@ public double height
 
         /// <summary>
         /// The Earth-Centered, Earth-Fixed X coordinate of the origin of the coordinate system, in meters.
-        /// This property is ignored unless <see cref="originAuthority"/> is
+        /// </summary>
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.EarthCenteredEarthFixed"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double ecefX
         {
             get => this._ecefX;
@@ -195,10 +263,14 @@ public double ecefX
 
         /// <summary>
         /// The Earth-Centered, Earth-Fixed Y coordinate of the origin of the coordinate system, in meters.
-        /// This property is ignored unless <see cref="originAuthority"/> is
+        /// </summary> 
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.EarthCenteredEarthFixed"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double ecefY
         {
             get => this._ecefY;
@@ -211,10 +283,14 @@ public double ecefY
 
         /// <summary>
         /// The Earth-Centered, Earth-Fixed Z coordinate of the origin of the coordinate system, in meters.
-        /// This property is ignored unless <see cref="originAuthority"/> is
+        /// </summary>
+        /// <remarks>
+        /// This property only takes effect if <see cref="CesiumGeoreference.originPlacement"/> is set to
+        /// <see cref="CesiumGeoreferenceOriginPlacement.CartographicOrigin"/> and
+        /// <see cref="originAuthority"/> is set to 
         /// <see cref="CesiumGeoreferenceOriginAuthority.EarthCenteredEarthFixed"/>.
         /// Setting this property changes the <see cref="originAuthority"/> accordingly.
-        /// </summary>
+        /// </remarks>
         public double ecefZ
         {
             get => this._ecefZ;
@@ -227,10 +303,12 @@ public double ecefZ
 
         /// <summary>
         /// The scale of the globe in the Unity world. If this value is 0.5, for example, one
-        /// meter on the globe occupies half a meter in the Unity world. The globe can also
-        /// be scaled by modifying the georeference's Transform, but setting this property instead
-        /// will do a better job of preserving precision.
+        /// meter on the globe occupies half a meter in the Unity world.
         /// </summary>
+        /// <remarks>
+        /// The globe can also be scaled by modifying the georeference's Transform, but setting 
+        /// this property instead will do a better job of preserving precision.
+        /// </remarks>
         public double scale
         {
             get => this._scale;
@@ -259,6 +337,9 @@ public double4x4 ecefToLocalMatrix
             }
         }
 
+        /// <summary>
+        /// The <see cref="CesiumEllipsoid"/> that is referenced.
+        /// </summary>
         public CesiumEllipsoid ellipsoid
         {
             get
@@ -391,7 +472,7 @@ public void ReloadEllipsoid()
             this.UpdateOtherCoordinates();
 
             Cesium3DTileset[] tilesets = GetComponentsInChildren<Cesium3DTileset>();
-            foreach(var tileset in tilesets)
+            foreach (var tileset in tilesets)
             {
                 tileset.RecreateTileset();
             }

Runtime/ConfigureReinterop.cs

@@ -393,6 +393,7 @@ public void ExposeToCPP()
             georeference.ecefX = georeference.ecefX;
             georeference.ecefY = georeference.ecefY;
             georeference.ecefZ = georeference.ecefZ;
+            georeference.originPlacement = georeference.originPlacement;
             georeference.originAuthority = georeference.originAuthority;
             georeference.scale = georeference.scale;
             double4x4 ecefToLocal = georeference.ecefToLocalMatrix;