stride/docs/quantum

Quantum — Overview

Quantum is Stride's graph-based introspection framework. It wraps any .NET object hierarchy into a typed node graph, and that graph is the single source of truth for three things: property grid display, undo/redo, and asset override tracking (the "bold = overridden" behaviour in prefab/archetype workflows).

Layers

flowchart TD
    A["Stride.Core.Quantum<br/>sources/presentation/Stride.Core.Quantum/<br/>Live node graph over .NET objects"]
    B["Stride.Core.Assets.Quantum<br/>sources/assets/Stride.Core.Assets.Quantum/<br/>Override tracking, base-asset linking"]
    C["Stride.Core.Presentation.Quantum<br/>sources/presentation/Stride.Core.Presentation.Quantum/<br/>INodePresenter — property grid view model"]
    D["Stride.Core.Assets.Editor<br/>sources/editor/Stride.Core.Assets.Editor/Quantum/<br/>IAssetNodePresenter, AssetNodePresenterUpdaterBase"]
    E["Stride.Assets.Presentation<br/>sources/editor/Stride.Assets.Presentation/NodePresenters/<br/>Concrete updaters per asset type"]

    A --> B
    B --> C
    C --> D
    D --> E

Data Flow

1. Asset opens — AssetPropertyGraph (created via AssetQuantumRegistry.ConstructPropertyGraph with the session's AssetPropertyGraphContainer) calls GetOrCreateNode(asset) on the underlying NodeContainer to build the core graph.
2. Override semantics — AssetPropertyGraph links each node to its counterpart in the base asset graph (if any) and marks inherited vs. overridden values.
3. Presenter tree — AssetNodePresenterFactory walks the node graph and creates one IAssetNodePresenter per node.
4. Updaters run — all registered INodePresenterUpdater implementations get UpdateNode() called per node, then FinalizeTree() called once for the full tree.
5. Property grid binds — the WPF property grid binds to the presenter tree: DisplayName → label, Value/UpdateValue → input control, IsVisible/IsReadOnly → visibility and editability, AttachedProperties → input constraints.

When You Need Quantum

Decision tree:

• Adding a new asset type with default property grid display? → No Quantum code needed. [DataMember] and [Display] attributes on the asset class are sufficient. See asset-system/README.md.

• Customising visibility, display names, numeric constraints, or computed properties for a new or existing asset? → Write an INodePresenterUpdater. See property-grid.md.

• Asset class holds members that are references to other content objects (Prefabs, Textures)? → Write an AssetPropertyGraphDefinition. See asset-graph.md.

• Custom override or inheritance behaviour (rare — scenes and prefabs already cover this)? → Subclass AssetPropertyGraph. See asset-graph.md.

Spoke Files

File	Covers
graph-model.md	IGraphNode, IObjectNode, IMemberNode, NodeContainer, mutations, change listeners
asset-graph.md	AssetPropertyGraph, override model, AssetPropertyGraphDefinition, AssetQuantumRegistry
property-grid.md	INodePresenter, IAssetNodePresenter, updater pipeline, INodePresenterUpdater cookbook