3D World

This integration allows dropping items from the UI inventory into a 3D scene and picking them back up. In the current package it is implemented as a Demo2 Loot example: WorldDropZone and WorldItem live under Examples, not in the core runtime.

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How It Works

flowchart LR
    subgraph Dropping
        A["Drag item\nfrom UI"] --> B["Drop onto\nworld zone"]
        B --> C["3D object\nappears"]
    end

    subgraph Picking_Up
        D["Approach\nthe object"] --> E["Interact"]
        E --> F["Item goes\nto inventory"]
    end

    Dropping ~~~ Picking_Up

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Components

Component	Purpose
WorldDropZone	UI area for dropping items into the world. On drop, creates a 3D object and removes the item from the inventory
WorldItem	Component on a 3D object in the world. In the demo it stores a reference to ItemExampleWith3DSO
ItemAdapterSoWith3DAdapter	Demo adapter that exposes a 3D prefab through its WorldPrefab property

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Setup

1. Use an adapter with WorldPrefab

public class ItemAdapterSoWith3DAdapter : IItemAdapter, IFilterable
{
    public readonly ItemExampleWith3DSO item;

    public string DisplayName => item.ItemName;
    public Sprite Icon => item.Icon;
    public GameObject WorldPrefab => item.WorldPrefab.gameObject;
}

In the current implementation, WorldDropZone from Demo2 Loot accepts ItemAdapterSoWith3DAdapter specifically. If your project uses a different adapter type, update CanAcceptEntry and the spawn logic accordingly.

2. Add WorldDropZone

Create a UI panel (Image with RectTransform) and add the WorldDropZone component. Configure:

• Spawn Point --- Transform point where 3D objects will appear.
• Randomize Position --- add random offset on spawn.
• Random Radius --- scatter radius.
• Area Highlight --- Image for highlighting the zone on hover (green = can drop, red = cannot).

3. Add WorldItem to 3D prefabs

On the 3D object prefab, add the WorldItem component. If you forget --- WorldDropZone will add it automatically on spawn.

To pick items back up into the inventory, implement your own interaction logic: on contact with the player, read worldItem.Item, add it to the inventory, and destroy the 3D object.

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Full Cycle

flowchart LR
    subgraph Drop["Dropping"]
        A["Player drags an item in the UI"] --> B["Drops it onto WorldDropZone"]
        B --> C["WorldDropZone checks the adapter\nand the WorldPrefab"]
        C --> D["Create a 3D object in the scene"]
        D --> E["Remove the item from inventory"]
    end

    subgraph Pickup["Picking Up"]
        F["Player approaches and interacts"] --> G["Item is added back to inventory"]
        G --> H["3D object is removed from the scene"]
    end
    Drop ~~~ Pickup

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Implementation Details

• WorldDropZone extends DropAreaBase using the simple consumption pattern --- it overrides CanAcceptEntry and ProcessEntry. Source removal and zone highlighting are handled automatically by the base class.
• WorldDropZone checks every item in the drag context: in the demo it must be an ItemAdapterSoWith3DAdapter with a non-null WorldPrefab. If even one item fails that check, the drop is rejected.
• For stacks, each instance is spawned as a separate object with a slight offset.
• Zone highlighting works automatically: green if the item can be dropped, red if it cannot.

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Class Reference

Class	Role
DropAreaBase	Base class for drop areas (see Drop Areas)
WorldDropZone	UI drop zone: creates 3D objects on drop
WorldItem	Component on a 3D object: in the demo it stores ItemExampleWith3DSO
ItemAdapterSoWith3DAdapter	Demo adapter with access to WorldPrefab