> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rollingquest.kramgames.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Block Selector

> How the block selector cursor works in the RollingQuest editor: 3D grid navigation, side selection, block grabbing, and visual feedback.

The Block Selector is a wireframe cursor that highlights the current position in the 3D block grid. It provides visual feedback for block placement, selection, and manipulation.

## Grid Navigation

The selector moves on integer grid coordinates `(X, Y, Z)`:

| Key   | Movement      |
| ----- | ------------- |
| **W** | +Z (forward)  |
| **S** | -Z (backward) |
| **A** | -X (left)     |
| **D** | +X (right)    |
| **E** | +Y (up)       |
| **Q** | -Y (down)     |

The selector position is displayed in the HUD as `[X, Y, Z]`.

## Selection Modes

### No Selection

The selector shows the current grid position. No faces are highlighted.

### Side Selected

One face of the selector is highlighted. This means a specific block side is selected for element placement.

* Achieved by **left-clicking** on a block face
* The raycast detects which face was clicked
* Only sides belonging to the current section can be selected

### Block Selected (Grabbed)

All six faces are highlighted. The block at this position is "grabbed" and can be moved.

* Achieved by pressing **Space** on an existing block
* Press **Space** again to ungrab
* Moving the selector with WASD/EQ moves the grabbed block

## Visual Feedback

The selector uses material properties to show selection state:

* Each face has a `_Selected` shader property (0 or 1)
* Selected faces render with a distinct color
* The visual updates every frame in `UpdateSelectionColors()`

## Block Movement

When a block is grabbed:

1. The selector and block move together
2. The editor checks if the destination is empty
3. If occupied, the movement is blocked
4. On successful move, the block is translated in the block network
5. All attached balls and enemies are repositioned
6. Illumination is recomputed

## Slot Position

The selector's position is a `BlockSlot` — a struct containing integer `(X, Y, Z)` coordinates. The position is converted to world space using `BlockSlot.Position` for rendering.

## Persistence

The selector position is saved between sessions:

* Stored in `EditorPersistentState.BlockSelectorPosition`
* Restored when the editor loads
* Default position: `(0, 0, 0)`