API Reference
Core types
| Type | Category | Description |
|---|
UCrimsonSkillTree | Asset | Tree data asset - nodes, graph config, presentations, connection paths |
UCrimsonSkillTree_Node | Asset | A single node - costs, activation conditions, node events, state |
UCrimsonSkillTree_Edge | Asset | Directed edge; per-edge conditions, events, color overrides, LOD |
UCrimsonSkillTreeManager | Runtime | Replicated component: budgets, levels, RPCs, loadouts, save data |
UCrimsonSkillTreeBlueprintLibrary | Runtime | BP helpers - node lookup, cost formatting, simulation |
Host contract
The actor that hosts a UCrimsonSkillTreeManager must implement `ICrimsonSkillTreeInterface` (all three methods are BlueprintNativeEvent). The manager calls these on its owning actor to resolve the logical effect owner; without the interface, initialization fails (crash in development builds, silent no-op in shipping - see Quick Start step 2).
| Method | Returns / purpose |
|---|
GetSkillTreeOwner() | The actor that logically owns the tree's effects - typically the controlled Pawn/Character |
GetSkillTreeOwnerCharacter() | The owning ACharacter (used by character-scoped events such as float-property modifiers) |
GetSkillTreeManagerComponent() | The host's UCrimsonSkillTreeManager instance |
Sub-node bases
| Type | Purpose |
|---|
UCrimsonSkillTree_ActivationConditionBase | Prerequisite check before a node activates |
UCrimsonSkillTree_NodeEventBase | Effect fired on level-up / level-down / reset |
UCrimsonSkillTree_EdgeConditionBase / UCrimsonSkillTree_EdgeEventBase | Edge-scoped condition / event |
FNodeResourceCost / FNodeCostDefinition | A cost (flat or curve-scaled) and its resource source |
Connection line styles
| Type | Description |
|---|
UCrimsonSkillTreeWidget_LineDrawingPolicyBase | Abstract, swappable connection-line strategy (GraphConfig.LineDrawingPolicy) |
USkillTreeLineDrawingPolicy_StraightLine / _ElbowLine | Built-in straight and elbow styles |
UCrimsonSkillTreeWidget_LineDrawingPolicy_Spline | Material-capable, designer-authored bezier connections |
UCrimsonSkillTreeWidget_SplineConnection | Runtime widget painting one spline connection (material strip / color fallback) |
FCrimsonSkillTree_ConnectionPath | Per-connection authored path (points, anchors, material) on ConnectionPaths |
FCrimsonSkillTree_SplineControlPoint | One control point: position + arrive/leave tangents + ECrimsonSplineTangentMode |
ECrimsonConnectionAnchorMode / ECrimsonSplineTangentMode | Attach mode and tangent mode enums |
Widgets
| Type | Description |
|---|
ICrimsonSkillTreeNodeWidget | The node contract. Implement on any UUserWidget to use it as a node - no plugin base class required. UCrimsonSkillTreeWidget_Node is a ready-made implementation you may subclass instead (On Update Node Appearance / On Node Hovered) |
ICrimsonSkillTreeDecorationWidget | The decoration contract (panel / header / divider). UCrimsonSkillTreeWidget_Decoration is the ready-made implementation |
UCrimsonSkillTreeUIStatics | Blueprint helpers a node needs without inheriting anything - Request Skill Node Action. UCrimsonSkillTreeWidget_NodeTooltip remains available as a ready-made tooltip |
| Screen + canvas | UCrimsonCoreSkillTreeScreen / UCrimsonCoreSkillTreeGraph - the ready-made runtime UI, in the CrimsonCore plugin |
Runtime structs & enums
| Type | Description |
|---|
FSkillNodeChangeRequest | A single node action in a batch (NodeGuid + ActionType) |
FSkillTreeLoadout | Named snapshot of node levels in a tree |
FCrimsonSkillTree_SaveGameData / _SaveGameNodeState | Plain save structs (in CrimsonSkillTree_SaveData.h) |
ECrimsonSkillNodeActionType | Activate / Deactivate / IncrementLevel / DecrementLevel |
ECrimsonNodeState | UnSet / Set / Max / Suppressed |
Config & extension
| Type | Description |
|---|
UCrimsonSkillTreeSettings | Project Settings -> Crimson -> Crimson Skill Tree |
UGameFeatureAction_AddCrimsonSkillTree | Game Feature action injecting a tree into an actor at runtime |
Built-in node events & conditions
| Type | Effect / Check |
|---|
UCrimsonSkillTree_NodeEvent_ApplyGameplayEffect | Applies/removes a GE scaled to the node level |
UCrimsonSkillTree_NodeEvent_GrantGameplayAbility | Grants/removes a Gameplay Ability |
UCrimsonSkillTree_NodeEvent_ModifyCharacterFloatProperty | Adds/subtracts a named float property on the owner |
UCrimsonSkillTree_ActivationCondition_ParentLevel | Parent node at/above a minimum level |
UCrimsonSkillTree_ActivationCondition_AttributeRequirement | A GAS attribute meets a threshold |
UCrimsonSkillTree_ActivationCondition_ResourcePointsSpent | A minimum number of points spent in the tree |
UCrimsonSkillTree_Condition_CompositeBase (+ _AND / _OR) | Combine conditions with AND / OR |
Connection visual states
| Type | Purpose |
|---|
ECrimsonConnectionVisualState | Locked / Unlockable / Active / Maxed - resolved from live node data |
FCrimsonConnectionLineStyle | Per-state look: color, thickness, brush (material-capable), opacity |
FCrimsonConnectionFillSettings | Progress-fill animation (FillAlpha material parameter, duration, easing, line-split fallback) |
FCrimsonConnectionTransitionSettings | State crossfade (duration, easing, optional material parameter) |
FCrimsonConnectionHoverSettings | Runtime hover (tolerance px, hover style, blend time) |
UCrimsonSkillTreeWidget_ConnectionLayer | Single widget painting all connections; hover hit-testing + OnConnectionHoverChanged |
UCrimsonSkillTreeWidget_LineDrawingPolicyBase::ResolveConnectionState/Style | State + style resolution (override points for custom policies) |
CrimsonSpline::BuildShapedPolyline | Chord + perpendicular shape-curve polyline (fixed 0..1 domain, endpoints pinned to the anchors) |