Runtime Level Design (Legacy)

Constructing Environments at Runtime

Runtime Level Design (RLD) functions as a foundational scripting system for developers who need to integrate level creation capabilities directly into their live applications. Unlike standard level design tools that operate within the Unity Editor interface, this system is specifically engineered to power in-game editors, modding suites, and player-facing construction tools. It serves as an API and a kickstarter for those building bespoke creation interfaces, providing the core mechanics required to manipulate objects and navigate scenes from a user perspective.

The system is designed to handle various environmental styles, from traditional dungeon layouts to organic nature scenes. Its utility extends to specialized geometry, such as spherical worlds, allowing for object placement and alignment on curved surfaces. This flexibility makes it a candidate for games where players are expected to modify their surroundings or for developers who need to build internal tools for live-ops environment tweaking.

Precision Manipulation and Gizmo Systems

The core of the interaction model relies on a suite of gizmos that mimic professional editing environments. The system includes standard Move, Rotate, and Scale gizmos, but also introduces specialized tools such as the Universal Gizmo, which combines movement, rotation, and scaling into a single interface for faster iteration. For architectural or modular workflows, the Extrude Gizmo provides a streamlined method for extending objects, which is particularly useful when laying out repetitive structural elements like corridors or walls.

Beyond standard transforms, the Box Scale Gizmo offers a different approach to volume adjustment, while the inclusion of Gizmo Transform Pivots and Transform Spaces allows users to toggle between local and global orientations. This level of control ensures that players or tool-users can achieve the same precision found in professional development environments. The system also supports a Unity-style camera, providing a familiar navigation experience for those accustomed to industry-standard 3D software.

Advanced Snapping and Alignment Logic

To facilitate clean and structured level design, the system incorporates multiple snapping layers. Object-to-Object snapping allows for the precise alignment of modular pieces, ensuring that edges and faces meet without gaps. This is complemented by Surface Snapping, which enables objects to adhere to the geometry below them. This surface logic is highly configurable, allowing for specific settings per layer and supporting advanced applications like snapping to spherical surfaces where objects must rotate and offset according to the surface normal.

For more granular control, Vertex Snapping is integrated into the Move and Universal gizmos. This allows users to snap specific points of a mesh to the vertices of another, which is essential for complex architectural snapping. Additionally, a Selection Grid Snap ensures that objects remain aligned to a predefined spatial increment, while keyboard-based Selection Rotation allows for quick, configurable steps along the X, Y, or Z axes without manual gizmo dragging.

Prefab Management and Selection Workflows

Handling assets at runtime requires a robust organization system, which is addressed through the Runtime Prefab Picker and Prefab Libraries. These tools allow developers to expose specific sets of assets to the user, who can then select and instantiate them within the world. The system supports object selection with customizable restrictions, ensuring that only certain elements of a scene are interactable at any given time. Users can also utilize features like ‘Duplicate Selected’ and ‘Duplicate Layer Mask’ to rapidly populate scenes with recurring assets.

While the system provides the tools for placement and manipulation, it does not include a native save/load API. Developers utilizing this system must implement their own data persistence solutions or integrate third-party save systems to store the level data generated during a session. Furthermore, the visual assets often seen in demonstrations—such as dungeon modules, trees, and rocks—are used for illustrative purposes and are not included in the core scripting package.

Technical Integration and Pipeline Support

The current version of the system supports the Standard Render Pipeline and the Universal Render Pipeline (URP). However, there are specific limitations regarding modern Unity features. For instance, the Render Graph is not supported, and the scene gizmo is unavailable when using URP. Developers working with Unity 6 should note that some features may not function as expected, as the system is currently in a legacy state while a full remake is developed to align with modern workflows and RenderGraph requirements.

The system remains a specialized choice for those needing to bridge the gap between a static game world and a dynamic, user-editable environment. By providing the API for selection, transformation, and snapping, it handles the complex math and interaction logic required for 3D spatial editing, leaving the developer to focus on the UI and game-specific implementation of the tools.