OpenSimulator Internals/Walkthroughs/Avatar Derezzes Object

Overview

Traces what happens in code, connectors, and database when an avatar takes an object from the world into inventory (derez), or deletes it. Uses the box-with-notecard from OpenSimulator Internals/Walkthroughs/Avatar Rezzes Box as the concrete example.

This is a concrete instance of OpenSimulator Internals/Walkthroughs/Avatar Acquires Inventory. Read that page for the full code path.

Case 1: Take (own object, no-copy)

Avatar right-clicks the box and selects Take.

1. Viewer Sends DeRezObject

Viewer sends DeRezObject packet with action=Take, objectLocalID=box local ID.
Scene.DeRezObjects() validates permissions (CanTakeObject).
Calls IInventoryAccessModule.CopyToInventory(DeRezAction.Take, folderID, [boxSOG], client, false).

2. Object Serialised

BasicInventoryAccessModule.CopyBundleToInventory():

Serialises box SOG to XML: SceneObjectSerializer.ToOriginalXmlFormat().
- XML includes: prim data, shape, permissions, position, rotation, task inventory (the notecard reference is embedded in the XML as a primitems-equivalent block).
Creates asset: AssetService.Store() -- new UUID, AssetType.Object, data = XML bytes.
CreateItemForObject(Take): determines folder (original FromFolderID if owner taking back own item).
AddPermissions(): same-owner path, preserves current permissions.
Scene.AddInventoryItem(): InventoryService.AddItem() -- writes inventoryitems row.
Sends SendInventoryItemCreateUpdate() to client.

DB writes

assets -- INSERT: new object XML asset UUID
inventoryitems -- INSERT: new item in Object folder (or original folder)

3. Object Removed from Scene

DoPostRezWhenFromItem():

Box was no-copy: InventoryService.DeleteItems() -- removes original inventoryitems row.

Scene.DeleteSceneObject(boxSOG, false):

RemoveScriptInstances() -- no-op (no scripts).
Removes physics actor.
UnlinkSceneObject() -- removes from scene graph.
SimulationDataService.RemoveObject(boxUUID, regionID).

DB writes

inventoryitems -- DELETE: original no-copy item
prims -- DELETE: box prim row
primshapes -- DELETE: box shape row
primitems -- DELETE: notecard task inventory row

4. DB State After

Region database:

prims: box row gone.
primshapes: box shape row gone.
primitems: notecard task inventory row gone.

Robust database:

assets: new object XML asset (contains the notecard reference inside the serialised XML).
inventoryitems: new item pointing to the new asset UUID.
The notecard asset itself remains in assets table -- assets are never deleted on take.

Case 2: Take Copy (copyable object)

Avatar right-clicks and selects Take Copy.

Same serialise-and-store process as above, but:

DoPostRezWhenFromItem() does NOT delete the original inventory item (item has Copy permission).
Scene.DeRezObjects() does NOT call DeleteSceneObject() -- object stays in world.

DB writes

assets -- INSERT: new object XML asset
inventoryitems -- INSERT: new item in Object folder

Region DB unchanged. The box stays in the world.

Case 3: Delete (move to Trash)

Avatar right-clicks and selects Delete.

Calls CopyToInventory(DeRezAction.Delete):

Destination folder: Trash (FolderType.Trash) if own object, Lost and Found if another's.
Same serialise-and-store process.
Scene.DeleteSceneObject() removes from scene and region DB.

DB writes

assets -- INSERT: serialised object XML
inventoryitems -- INSERT: item in Trash
prims/primshapes/primitems -- DELETE

Key DB Tables Affected

Table	Take (no-copy)	Take Copy	Delete
assets	INSERT (new)	INSERT (new)	INSERT (new)
inventoryitems	INSERT new + DELETE old	INSERT new only	INSERT (Trash)
prims	DELETE	unchanged	DELETE
primshapes	DELETE	unchanged	DELETE
primitems	DELETE	unchanged	DELETE

Note: asset rows are never deleted from the assets table by any of these operations. Assets accumulate. Cleanup is a separate administrative operation outside normal simulator operation.

What Happens to the Notecard Inside

The notecard was task inventory of the box (a primitems row). When the box is taken or deleted:

The primitems row is deleted from the region DB.
The notecard asset (text content) remains in the assets table -- it is referenced by assetID in the serialised object XML.
When the box is later rezzed from inventory, the XML is deserialised and the notecard reappears as task inventory -- it is re-fetched from assets by assetID.

The notecard is not duplicated into the avatar's personal inventory (inventoryitems). It stays embedded in the object asset.