# ASHVEIL ENGINE by Guassia — capability atlas

Checked **2026-09-24** against official Blender 5.2 LTS and Unreal Engine 5.8 documentation and the local Guassia source. This is a **baseline audit**, before the current local-project, open-ground, camera and review-asset changes are promoted. It is not a release receipt.

This inventory contains **144 workflow-level capabilities across 18 domains**: **34 scoped source implementations, 56 partial implementations, 54 missing integrated workflows**. Counts describe this inventory, not every tool in either product. A complete operator/API census would require version-pinned manual/API manifests, plugins and platform scopes; it cannot honestly be inferred from category pages. No feature-parity percentage is meaningful from these counts.

## How to read the inventory

- **Implemented** means a specific source path exists for the stated scope. It does not assert Blender/Unreal parity, production maturity or fresh browser QA.
- **Partial** means a foundation or narrower workflow exists; the gap is explicit.
- **Missing** means no integrated creator workflow was located in the inspected modules. It is a roadmap item, not a claim that every repository byte was searched.
- Comparator operation summaries are deliberately short. The Gaussian designs and prioritization are our engineering analysis, not claims made by Blender or Epic.
- Official current/indexed pages were inspected. Several Blender direct-page fetches returned 402/challenge; indexed official material supplied the cited coverage. No challenge bypass or complete crawl is claimed.

## Immediate decisions

1. **Make external local project files a first-class workflow.** Existing browser-local autosave and the `.guassia.json` metadata download are not a self-contained editable project. Add visible Save Project / Save As / Open Project, pack all referenced Gaussian and original audio bytes, validate before swapping the active draft, and test reopening in an empty browser profile. Keep website-export, project-save and publication separate.
2. **Start outdoors on white ground.** New projects should have an open white floor, a simple sky/background and no walls, ceiling, music, NPCs or objectives. Retain room/region data as authorable boundaries without forcing visible room shells. Do not migrate existing creator worlds destructively.
3. **Distinguish authoring cameras from game cameras.** Keep top-down and in-scene editor navigation. Add serialized first-person, third-person and fixed gameplay rigs; define movement-relative-to-camera behavior and collision recovery independently.
4. **Review ten assets before scaling production.** Use actual 3D Gaussian assets, not flat images described as models. Present full-resolution 3840 × 2160 renders and near crops with source counts, bounds, hashes, camera settings and actual representation/provenance. Owner approval is a visual-quality gate, not a benchmark result.
5. **Build streaming before lifting limits again.** A larger integer cap does not deliver a larger usable world. Track authored totals, source residency, active candidates, drawn contributions and frame time separately.

## What 4K and large Gaussian worlds mean

A 4K frame is 3840 × 2160 pixels. A conventional “4K texture” often refers to a roughly 4096-pixel image map; native Gaussian color/appearance data is not a UV texture resolution. An asset should therefore be described by its source representation, spatial detail, capture coverage, appearance channels, viewing range and validated output. A 4K render of a low-detail source remains low detail.

“Infinite Gaussians” cannot mean infinite simultaneous memory or draw work on finite hardware. The useful goal is worlds larger than the resident working set: immutable compressed chunks, shared references, asynchronous IO, view-dependent Gaussian LOD, eviction, and a measured frame/memory budget. An unbounded authored address space is also constrained by storage and identifiers. None establishes infinite fidelity or performance.

The inspected browser baseline allows 5,000,000 authored instantiated Gaussians, 1,000,000 per imported source, and 5,000,000 source-library Gaussians; source definition/object/room/NPC limits are independent. Active object previews are capped by tier at 120,000 / 350,000 / 1,000,000 and source previews at 250,000 / 750,000 / 1,500,000. This is bounded sampling, not true hierarchical LOD. A prior documented synthetic five-million-authored test reported 84.2 ms of CPU plus awaited-renderer work at 1214 × 758 with 350,000 active preview samples. It is not isolated GPU time, a 4K result or a smooth-frame-rate guarantee. See `gaussia/GAUSSIAN-CAPACITY.md`; this audit did not rerun that benchmark.

## Workflow inventory

### 01 Projects and durable files

Sources: [Blender file workflows](https://docs.blender.org/manual/en/latest/files/blend/index.html) · [Packed data](https://docs.blender.org/manual/nl/5.2/files/blend/packed_data.html) · [Packaging projects](https://dev.epicgames.com/documentation/en-us/unreal-engine/packaging-your-project).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/sketchpad.js`, `gaussia/project.js`, `gaussia/export-world.js`, `gaussia/import-world.js`, `engine/native-format.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 01-01 | Editable project Save/Open | partial | Save document and reopen its dependencies. | JSON draft download exists but its imported files remain in browser storage; add a conspicuous self-contained project package and transactional Open. |
| 01-02 | Save As and Save Copy | partial | Separate working document from backup copy. | Download-only draft export has no retained filesystem handle; explicit Save As, filename and dirty state should be shared by web and desktop. |
| 01-03 | Resource packing | implemented | Bundle referenced resources for portability. | Playable ZIP packs referenced Gaussian and original audio bytes; keep an editable data-only project format distinct from executable runtime files. |
| 01-04 | Browser local draft | implemented | Persist working state between sessions. | localStorage stores project metadata and IndexedDB stores media; this is device/origin-bound and is not a durable external backup. |
| 01-05 | Recovery and autosave | partial | Recover prior work after interruption. | Core world recovery helpers exist; integrate rolling project generations with assets, timestamps and recovery UI. |
| 01-06 | Versioned native asset files | implemented | Store typed data and file versions. | GAsset uses a binary chunk directory and CRC checks; this does not mean all future attributes are supported. |
| 01-07 | Relative dependency resolution | partial | Resolve document references after relocation. | ZIP import remaps bundled dependencies; add explicit missing-resource repair and external-link policies. |
| 01-08 | Project migration | partial | Translate older schemas on open. | Validators reject unsupported data; add documented migration fixtures before format changes. |

### 02 Editor interface and scene organization

Sources: [Interface preferences](https://docs.blender.org/manual/de/5.2/editors/preferences/interface.html) · [Object and object-data separation](https://docs.blender.org/manual/en/latest/scene_layout/object/introduction.html) · [Building Virtual Worlds](https://dev.epicgames.com/documentation/en-us/unreal-engine/building-virtual-worlds-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/sketchpad.js`, `gaussia/pages.cjs`, `gaussia/scene-viewport.js`, `gaussia/asset-workbench.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 02-01 | Empty starting scene | partial | Create a project from a template. | Baseline freshProject creates an empty enclosed room; owner now requests open white ground and outdoor context with no authored props. |
| 02-02 | Workspace layouts | partial | Arrange specialized editors for a task. | Current panels are fixed disclosure sections; add dockable, keyboard-accessible saved layouts only after workflows stabilize. |
| 02-03 | Outliner and hierarchy | partial | Select and organize scene objects. | Room and object lists exist; nested transform parenting and a full searchable outliner remain absent. |
| 02-04 | Property inspector | implemented | Edit the active object's properties. | Numeric transform, appearance, collision and behavior fields are wired to project validation. |
| 02-05 | Multiple scenes and layers | partial | Separate scene content and visibility. | Rooms and group IDs exist; editable layers, collections and cross-scene dependency management are incomplete. |
| 02-06 | Undo and redo | partial | Reverse command transactions. | Object editor and core commands have undo paths; whole-project audio, scene and filesystem transactions are not one unified history. |
| 02-07 | Search and command palette | missing | Find operators without navigating menus. | Add one command registry with discoverable names, shortcuts and undo semantics. |
| 02-08 | Units and measurement | partial | Interpret transforms in a common scale. | Coordinates and collision use source metres; add visible unit settings, rulers and import scale confirmation. |

### 03 Placement, references and editing

Sources: [Object transforms](https://docs.blender.org/manual/en/latest/scene_layout/object/editing/transform/introduction.html) · [Object and object-data separation](https://docs.blender.org/manual/en/latest/scene_layout/object/introduction.html) · [Split to Instances](https://docs.blender.org/manual/en/5.2/modeling/geometry_nodes/geometry/operations/split_to_instances.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/asset-transform-tools.js`, `gaussia/asset-edit.js`, `engine/gaussian-core.js`, `engine/gaussian-render-bridge.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 03-01 | Object translate rotate scale | implemented | Transform an object independently of geometry. | Instance TRS updates shared Gaussian references; ordinary movement does not rewrite source positions. |
| 03-02 | Multi-object transforms | implemented | Apply a common transform to selection. | Selection supports move, yaw and positive uniform scale with route offsets and one undo step. |
| 03-03 | Grid snap and alignment | implemented | Place selected origins precisely. | Origin snap, alignment and distribution exist; surface/normal snapping is a later extension. |
| 03-04 | Instanced duplication | implemented | Share source data among objects. | Copies reference one immutable Gaussian source and hold independent transforms and appearance. |
| 03-05 | Parent-child transforms | missing | Compose child motion through parents. | Add transform hierarchy with cycle checks and local/world reparent choices; group labels currently are not parents. |
| 03-06 | Reusable prefabs | partial | Instantiate a reusable assembly. | Group duplication and baked room assemblies exist; linked prefab revisions and per-instance override propagation do not. |
| 03-07 | Object origin and pivot tools | partial | Choose the center of transformation. | Selection centroid transforms exist; editable asset pivot and arbitrary cursor pivots need preserved source-space offsets. |
| 03-08 | Sparse edit layers | partial | Apply non-destructive overrides. | Core color/opacity/deletion/semantic layers and dirty ranges exist; full authoring integration and layer-preserving builder round trips are incomplete. |

### 04 Asset acquisition and formats

Sources: [Working with Content](https://dev.epicgames.com/documentation/en-us/unreal-engine/working-with-content-in-unreal-engine) · [Packed data](https://docs.blender.org/manual/nl/5.2/files/blend/packed_data.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/asset-pipeline.js`, `gaussia/asset-store.js`, `ply-parser.js`, `model-to-splats.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 04-01 | Gaussian PLY import | implemented | Read a supported asset format. | Decode supported means, scale/orientation, opacity and color; declare unsupported appearance channels rather than silently implying full fidelity. |
| 04-02 | Native GAsset import | implemented | Load native authoring data. | Validate bounded binary Gaussian arrays and asset metadata before use. |
| 04-03 | Static GLB conversion | implemented | Convert imported model data. | Sample supported model surfaces into a new Gaussian visual asset; original triangles are import inputs, not runtime authority. |
| 04-04 | Image conversion | implemented | Turn raster content into scene content. | Adaptive pixel regions create a flat Gaussian image plane; this is not inferred complete 3D geometry. |
| 04-05 | USD and scene interchange | missing | Exchange complex structured scenes. | Define subset mapping for transforms, instances, cameras and appearance before supporting a format badge. |
| 04-06 | FBX and animation interchange | missing | Import rigs and motion clips. | Create skeleton, clip and binding schemas first; static model conversion does not supply them. |
| 04-07 | Capture reconstruction | missing | Reconstruct a scene from observations. | An offline capture/training pipeline needs calibrated multi-view inputs, provenance and confidence; editing should not require retraining. |
| 04-08 | Asset reimport and provenance | partial | Update source while retaining edits. | Local metadata and source copies exist; stable-ID reimport remapping and conflict review remain work. |

### 05 Splat modeling and selection

Sources: [Surface authoring](https://docs.blender.org/manual/en/latest/modeling/surfaces/index.html) · [Sculpting introduction](https://docs.blender.org/manual/en/latest/sculpt_paint/sculpting/introduction/index.html) · [Modifier stack](https://docs.blender.org/manual/en/latest/modeling/modifiers/introduction.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/asset-workbench.js`, `gaussia/asset-quality.js`, `gaussia/asset-pipeline.js`, `engine/spatial-index.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 05-01 | Primitive creation | implemented | Begin from simple shapes. | Built-in Gaussian primitives are useful blockout assets; they do not establish photorealism. |
| 05-02 | Brush and lasso selection | partial | Select a spatially defined region. | Spatial query foundations exist; interactive splat-level brush/lasso tools with visible depth control need integration. |
| 05-03 | Semantic and color selection | partial | Select by attributes. | Core semantics and color data exist; builder selection UI currently primarily addresses whole objects. |
| 05-04 | Splat sculpting | missing | Deform selected local surface structure. | Apply weighted mean/covariance deltas in an edit layer; retain source and expose density compensation. |
| 05-05 | Densify and prune | partial | Adjust local representation density. | Cleanup removes selected bad splats; quality-aware densification and locally error-bounded pruning are not delivered. |
| 05-06 | Smooth and relax | missing | Regularize local shape or attributes. | Use neighborhood-aware filters that protect discontinuities, thin surfaces and semantic boundaries. |
| 05-07 | Curves text and surfaces | missing | Author parametric geometry. | Sample curves, glyph outlines and analytic surfaces directly into adaptive Gaussian patches without requiring a visible mesh. |
| 05-08 | Approximate booleans | missing | Combine or subtract volumes. | Operate on density/SDF masks and regenerate only affected splat clusters; disclose approximation and material-boundary limits. |

### 06 Asset detail and close-range quality

Sources: [Color attribute painting](https://docs.blender.org/manual/en/latest/sculpt_paint/sculpting/introduction/painting.html) · [Working with Content](https://dev.epicgames.com/documentation/en-us/unreal-engine/working-with-content-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/asset-quality.js`, `gaussia/asset-workbench.js`, `gaussia/gaussian-capacity.js`, `gaussia/GAUSSIAN-CAPACITY.md`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 06-01 | Close-view inspection | implemented | Preview an asset before placement. | Asset preview offers near and eye-height inspection; judge thin edges and translucent overlap in movement too. |
| 06-02 | Adaptive detail sampling | partial | Preserve high-information regions. | Image edge variation and existing source sampling guide density; no universal screen-space error guarantee. |
| 06-03 | Floater cleanup | implemented | Remove likely stray elements. | Preview opacity, radius and neighbor filters on a copy; isolated thin details can be valid and must remain reversible. |
| 06-04 | Boundary repair | missing | Repair broken silhouettes and holes. | Add support-aware edge diagnostics and guided local resampling rather than global splat multiplication. |
| 06-05 | Per-splat painting | partial | Change local appearance attributes. | Sparse color patch foundation exists; a responsive brush, blending modes and layer UI are not integrated. |
| 06-06 | 4K asset validation | partial | Evaluate output at a target resolution. | 4K framebuffer support exists; asset certification requires fixed close cameras, legible details, motion and measured render cost. |
| 06-07 | Detail grading and variants | missing | Compare quality tiers consistently. | Package source plus representative levels with annotated errors; never label all source counts as equally good. |
| 06-08 | Capture artifact diagnostics | missing | Expose uncertainty or bad reconstruction. | Display coverage/confidence, stretched splats and unsupported viewing directions during import review. |

### 07 Materials and light transport

Sources: [Rendering systems](https://docs.blender.org/manual/en/5.2/render/index.html) · [Visuals and rendering](https://dev.epicgames.com/documentation/en-us/unreal-engine/designing-visuals-rendering-and-graphics-with-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/visual-effects.js`, `gaussia/playtest.js`, `spark-renderer.js`, `engine/gaussian-core.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 07-01 | Color opacity and tint | implemented | Control basic appearance. | Per-source color and instance overrides exist with Gaussian alpha compositing. |
| 07-02 | View-dependent appearance | partial | Vary appearance with viewing direction. | Some upstream capture data may contain SH; the full builder import/export representation does not preserve all coefficients. |
| 07-03 | Material node graph | missing | Compose appearance from typed nodes. | Compile bounded Gaussian inputs and material operations; avoid pretending a color field is a material editor. |
| 07-04 | PBR material attributes | missing | Describe surface light response. | Add normals, albedo, roughness, metallic and emission with explicit asset classes and defaults. |
| 07-05 | Dynamic direct lighting | partial | Evaluate light response in real time. | Reactive visual light effects exist; robust physically meaningful relighting of captured surfaces is not delivered. |
| 07-06 | Dynamic shadows | missing | Account for occluded light. | Investigate Gaussian opacity/deep shadow methods or disclosed invisible proxies, with temporal and leakage tests. |
| 07-07 | Reflections and global illumination | missing | Approximate indirect light transport. | Use probes or a measured Gaussian-aware transport path; baked source radiance is not dynamic GI. |
| 07-08 | Color management | partial | Interpret and display color consistently. | Color arrays and renderer output exist; a calibrated scene-linear/HDR/display transform workflow remains incomplete. |

### 08 Environments and world building

Sources: [Building Virtual Worlds](https://dev.epicgames.com/documentation/en-us/unreal-engine/building-virtual-worlds-in-unreal-engine) · [World Partition](https://dev.epicgames.com/documentation/en-us/unreal-engine/world-partition-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/project.js`, `gaussia/playtest.js`, `gaussia/progression-tools.js`, `gaussia/visual-effects.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 08-01 | Floor sky and background authoring | partial | Establish an environment around assets. | Current room and fog parameters are limited; make open ground and background independent optional environment components. |
| 08-02 | Terrain editing | missing | Shape large land surfaces. | Author a density/height field converted to Gaussian tiles with independent collision and change tracking. |
| 08-03 | Foliage scattering | missing | Place repeated vegetation procedurally. | Instance shared Gaussian foliage by region seed and density, with streamed placement data and collision policy. |
| 08-04 | Water and atmosphere | partial | Represent environmental media. | Fog and effects are available; convincing water, cloud transport and weather are substantial missing systems. |
| 08-05 | Room transitions | implemented | Move between authored spaces. | Local transitions and achievement gates validate destinations and reset on restart. |
| 08-06 | World partition streaming | missing | Load spatial cells on demand. | The builder loads bounded asset sets; room visibility is not asynchronous out-of-core world streaming. |
| 08-07 | Large-coordinate precision | missing | Keep distant positions stable. | Use world cell coordinates plus local origins and renderer-relative values; current bounded coordinates are not a planet-scale runtime. |
| 08-08 | Collaborative world editing | missing | Coordinate shared scene changes. | Requires authenticated revisions, locks/conflict merge and authoritative writes; browser drafts are local. |

### 09 Visibility, residency and rendering budgets

Sources: [World Partition](https://dev.epicgames.com/documentation/en-us/unreal-engine/world-partition-in-unreal-engine) · [Visuals and rendering](https://dev.epicgames.com/documentation/en-us/unreal-engine/designing-visuals-rendering-and-graphics-with-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/gaussian-capacity.js`, `engine/spatial-index.js`, `engine/gaussian-render-bridge.js`, `chunk-loader.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 09-01 | Hierarchical Gaussian LOD | partial | Choose detail by projected error. | Spatial structures and preview sampling exist; integrated reversible multi-level Gaussian LOD with error metrics does not. |
| 09-02 | Per-view culling | partial | Discard noncontributing scene content. | Active-room and renderer visibility are present; full world/cell/cluster contribution culling needs measurement and integration. |
| 09-03 | Asynchronous chunk loading | partial | Fetch scene data without blocking. | Film chunk-loader foundation is separate from general authoring assets; connect range reads, progress and cancellation to world cells. |
| 09-04 | Residency and eviction | partial | Keep an active memory working set. | Startup preview caps and bounded audio cache exist; dynamic Gaussian VRAM eviction is not implemented. |
| 09-05 | GPU editing compute | missing | Process selected attributes on GPU. | Brush/mask/filter dispatch must operate on resident blocks and read back only needed summaries. |
| 09-06 | GPU instance batching | partial | Submit repeated content efficiently. | Shared references and dirty bridge updates exist; many-instance measured renderer overhead remains substantial. |
| 09-07 | Temporal stability | partial | Keep sorting and transitions consistent. | Renderer handles splats, but pop/flicker metrics and coherent representative transitions are not a verified engine feature. |
| 09-08 | Performance budget adaptation | partial | Adjust quality to measured constraints. | Static tiers and coarse device-memory hints exist; actual GPU-time/VRAM feedback requires supported measurement. |

### 10 Cameras and player input

Sources: [Cameras](https://dev.epicgames.com/documentation/en-us/unreal-engine/cameras-in-unreal-engine) · [Rendering systems](https://docs.blender.org/manual/en/5.2/render/index.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/scene-camera.js`, `gaussia/scene-viewport.js`, `gaussia/playtest-input.js`, `gaussia/playtest.js`, `engine/topdown-game.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 10-01 | Perspective authoring camera | implemented | Navigate a three-dimensional scene. | In-scene authoring supports free movement and click-drag looking independently of gameplay. |
| 10-02 | Orthographic authoring camera | implemented | Edit without perspective scaling. | Top-down projection and room/selection framing are implemented. |
| 10-03 | First-person game camera | implemented | View from the controlled player. | Current playtest is first-person with movement, look and interaction. |
| 10-04 | Third-person game camera | missing | Follow an avatar from an offset. | At baseline no general creator-facing follow rig with collision avoidance; coordinate with current camera implementation work. |
| 10-05 | Fixed game cameras | missing | Use authored viewpoints for play. | At baseline no reusable creator camera set with entry conditions, framing and cut/blend rules. |
| 10-06 | Camera sequencing and blending | partial | Animate viewpoint changes over time. | Film paths exist separately; game camera tracks and transition controls need integrated serialization and preview. |
| 10-07 | Mouse capture fallback | implemented | Keep looking usable when capture fails. | Click-and-drag, sensitivity and invert-Y coexist with pointer lock and pause. |
| 10-08 | Touch controller remapping | partial | Adapt play input to devices. | Mobile joystick and look/interact controls exist; full rebinding, gamepad profiles and accessibility options remain work. |

### 11 Gameplay, stories and rules

Sources: [Gameplay Systems](https://dev.epicgames.com/documentation/en-us/unreal-engine/gameplay-systems-in-unreal-engine) · [Blueprints Visual Scripting](https://dev.epicgames.com/documentation/en-us/unreal-engine/blueprints-visual-scripting-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/story-schema.js`, `gaussia/story-runtime.js`, `gaussia/game-script-schema.js`, `gaussia/game-script-runtime.js`, `gaussia/game-script-editor.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 11-01 | Optional goals and endings | implemented | Evaluate game rules and completion. | Required collectible IDs, exits, endings and restart are authored; new projects need no story. |
| 11-02 | Notes and journal | implemented | Present narrative state to players. | Readable notes and achievement history are available without fabricated real-world content. |
| 11-03 | Triggers and actions | implemented | Respond to events or proximity. | Reveal/hide, doors, sound and progression integrate through checked IDs. |
| 11-04 | Restricted game scripting | implemented | Execute authored rules over events. | Guassia Script v1 is deterministic bounded JSON with variables and event handlers, not arbitrary code. |
| 11-05 | Visual scripting canvas | missing | Connect typed event and value nodes. | A visual editor should serialize the same validated script IR and preserve quotas rather than execute imported JavaScript. |
| 11-06 | Reusable gameplay components | partial | Compose behavior into entities. | Several fixed object behaviors exist; user-defined component schemas and reusable packages are not complete. |
| 11-07 | Gameplay save state | missing | Persist a player's progress. | Separate user progress from creator project data, version it and test checkpoint/load/reset semantics. |
| 11-08 | Abilities inventory and timers | partial | Manage reusable gameplay state. | Core top-down demo and script counters cover examples; general item, ability, equipment and cooldown authoring is incomplete. |

### 12 NPC intelligence and navigation

Sources: [Gameplay Systems](https://dev.epicgames.com/documentation/en-us/unreal-engine/gameplay-systems-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/npc-authoring.js`, `gaussia/npc-runtime.js`, `gaussia/world-objects.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 12-01 | Patrol route authoring | implemented | Move agents through waypoints. | Visual and numeric routes, pause times and loop modes are editable. |
| 12-02 | Perception and pursuit | implemented | React to observed targets. | Directional sight, last-seen memory, pursuit bounds and reset controls exist. |
| 12-03 | Look-away watcher behavior | implemented | Move only when not observed. | A watcher preset supports the requested horror behavior; it is rigid-agent motion rather than skeletal acting. |
| 12-04 | Follow and flee behavior | implemented | Maintain or increase target distance. | Companion/flee presets support direct ground-plane steering. |
| 12-05 | Pathfinding around obstacles | missing | Find a route through traversable space. | Add invisible navigation grid/SDF or explicitly permitted proxy navmesh; direct pursuit can get stuck. |
| 12-06 | Behavior tree or state graph | missing | Compose conditional AI decisions. | Build reusable bounded node/state assets with explicit transitions and debugger. |
| 12-07 | Crowd avoidance | partial | Avoid collisions among many agents. | Demo crowd motion exists outside creator-general navigation; no verified scalable reciprocal avoidance. |
| 12-08 | NPC debugger | partial | Inspect state and perception. | Current debug state helps small scenes; add visible paths, sight cones, decisions and event timelines. |

### 13 Physics and simulation

Sources: [Gameplay Systems](https://dev.epicgames.com/documentation/en-us/unreal-engine/gameplay-systems-in-unreal-engine) · [Blender 5.2 LTS manual index](https://docs.blender.org/manual/en/5.2/index.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/world-objects.js`, `gaussia/story-schema.js`, `engine/topdown-game.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 13-01 | Separate collision proxies | implemented | Test movement against simplified shapes. | Invisible compound boxes preserve Gaussian visual authority and allow open arches. |
| 13-02 | Character movement collision | partial | Move a controller safely. | Swept subdivision and safe-spawn checks exist; full step/slope/jump/capsule behavior needs an explicit solver. |
| 13-03 | Rigid-body dynamics | missing | Integrate forces and contacts. | Use transform-driven bodies with mass, inertia, friction, sleep and continuous collision where required. |
| 13-04 | Joints constraints and motors | missing | Constrain body relationships. | Add typed solver constraints; rigid movement must update instance transforms only. |
| 13-05 | Destruction | missing | Detach simulated parts after impact. | Create cluster bonds and collision pieces; retain source splats and activate detached instances. |
| 13-06 | Cloth soft bodies and fluids | missing | Simulate deforming media. | Drive Gaussian deformation from bounded solver structures; no neural retraining per edit. |
| 13-07 | Vehicles | missing | Simulate vehicle movement. | Add chassis/wheel proxy dynamics and control interfaces after a stable rigid-body solver. |
| 13-08 | Simulation baking | missing | Cache simulation for deterministic playback. | Store compact transform/deformation tracks and provenance; avoid dumping rewritten full datasets each frame. |

### 14 Animation and articulation

Sources: [Animation and rigging](https://docs.blender.org/manual/en/5.2/animation/index.html) · [Animation operation](https://docs.blender.org/manual/en/5.2/animation/introduction.html) · [Animating characters and objects](https://dev.epicgames.com/documentation/en-us/unreal-engine/animating-characters-and-objects-in-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `film-character.js`, `film-character-codec.js`, `film-motion.js`, `automation-engine.js`, `gaussia/world-objects.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 14-01 | Transform animation | partial | Interpolate object properties over time. | Spin/bob and film automation exist; general creator keyframe tracks need a shared scene timeline. |
| 14-02 | Skeleton and skin bindings | partial | Deform visual data from bones. | Film character pipeline is specialized; arbitrary authored skinned Gaussian assets are not integrated into the builder. |
| 14-03 | Animation clips and blending | partial | Combine reusable motion sequences. | Film motion supports its demo paths; user clip import, blend trees and state authoring remain incomplete. |
| 14-04 | Inverse kinematics | missing | Solve joint chains toward targets. | Apply bone transforms and correct Gaussian covariance; test stretch, scale and joint coverage. |
| 14-05 | Retargeting | missing | Transfer motion between skeletons. | Require explicit bone mappings and reference poses with visual validation. |
| 14-06 | Morph targets and shape keys | missing | Blend alternate shape states. | Use sparse deformation basis or structured bindings rather than full independent copied assets. |
| 14-07 | Rig authoring | missing | Create animator-facing controls. | Expose constraints, handles and safe bind/rebind workflows with joint debug overlays. |
| 14-08 | Animation events and root motion | missing | Couple timed motion to gameplay. | Create deterministic event/seek policies and controlled root transform extraction for collision. |

### 15 Audio, effects and cinematics

Sources: [Audio](https://dev.epicgames.com/documentation/en-us/unreal-engine/audio-in-unreal-engine) · [Animating characters and objects](https://dev.epicgames.com/documentation/en-us/unreal-engine/animating-characters-and-objects-in-unreal-engine) · [Render output](https://docs.blender.org/manual/en/5.2/render/output/properties/output.html) · [Video editing workflows](https://docs.blender.org/manual/en/latest/video_editing/edit/index.html) · [Motion tracking](https://docs.blender.org/manual/en/5.2/movie_clip/tracking/introduction.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/spatial-audio.js`, `gaussia/music-plugins.js`, `gaussia/music-visuals.js`, `film-job.cjs`, `render-job.cjs`, `automation-engine.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 15-01 | Spatial sound sources | implemented | Position sounds around a listener. | Web Audio emitters, one-shots and room fades operate with bounded voices and decoding. |
| 15-02 | Audio mixing and routing | partial | Combine and control signals. | Volume and source routing exist; buses, send effects, occlusion and an authorable mixer need development. |
| 15-03 | Audio-reactive effects | implemented | Drive visuals from audio measurements. | Optional music plugins alter supported Gaussian effects; they must never be forced into a new scene. |
| 15-04 | Particle and effect graphs | missing | Author procedural visual behavior. | Use Gaussian emitters/fields with typed bounded graphs and lifetime budgets. |
| 15-05 | Cinematic timeline | partial | Sequence cameras objects and audio. | Native music/film timelines exist; general game-scene sequencer is not integrated. |
| 15-06 | Offline video export | partial | Render timed frames to media. | Native render jobs exist; universal browser scene film export and full parity are not established. |
| 15-07 | Compositing and edit suite | missing | Combine layers and edit shots. | Add image/depth/ID output passes and graph operations only after a stable render contract. |
| 15-08 | Motion tracking and reconstruction | missing | Solve motion from footage. | External/imported calibrated camera tracks can seed a future Gaussian capture pipeline; not available in creator UI. |

### 16 UI, extensibility and production

Sources: [Creating user interfaces](https://dev.epicgames.com/documentation/en-us/unreal-engine/creating-user-interfaces-with-umg-and-slate-in-unreal-engine) · [Blueprints Visual Scripting](https://dev.epicgames.com/documentation/en-us/unreal-engine/blueprints-visual-scripting-in-unreal-engine) · [Unreal Engine documentation](https://dev.epicgames.com/documentation/en-us/unreal-engine) · [Interface preferences](https://docs.blender.org/manual/de/5.2/editors/preferences/interface.html) · [Blender 5.2 LTS manual index](https://docs.blender.org/manual/en/5.2/index.html).

Evidence modules (relative to `ashveil-visualizer`): `gaussia/i18n.js`, `gaussia/i18n-translations.mjs`, `gaussia/game-script-editor.js`, `guassia-platform/worker.js`, `guassia-client/main.cjs`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 16-01 | Game UI editor | missing | Lay out interactive player widgets. | Current HUD is fixed; add declarative widgets, data bindings and focus navigation without injected scripts. |
| 16-02 | Interface localization | partial | Translate application UI resources. | Locale dictionaries and six-language work exist; complete human-reviewed engine/tutorial coverage must be verified separately. |
| 16-03 | Creator content localization | missing | Localize game-authored content. | Use string IDs and creator-supplied translations, with fallbacks; do not silently machine-rewrite authored stories. |
| 16-04 | Accessibility authoring | partial | Support varied input and perception. | Keyboard forms and touch controls exist; captions, contrast tests, remapping and screen-reader gameplay need explicit features. |
| 16-05 | Native extension SDK | missing | Extend the engine through stable APIs. | A sandboxed trusted capability model must precede native plugins; arbitrary library loading is not enabled. |
| 16-06 | Project source control | missing | Track and merge creator edits. | Engine repository Git is not creator project revision control; use asset hashes and scene-aware merges. |
| 16-07 | Automated build pipeline | partial | Produce repeatable validated artifacts. | Build/package scripts exist; per-creator isolated build workers and verified delivery are not live. |
| 16-08 | Accounts and deployment | partial | Authenticate creators and publish worlds. | Local platform code and draft flows are not proof of deployed account, publishing or entitlement services. |

### 17 Networking, release and diagnostics

Sources: [Gameplay Systems](https://dev.epicgames.com/documentation/en-us/unreal-engine/gameplay-systems-in-unreal-engine) · [Packaging projects](https://dev.epicgames.com/documentation/en-us/unreal-engine/packaging-your-project) · [Testing and optimizing content](https://dev.epicgames.com/documentation/en-us/unreal-engine/testing-and-optimizing-your-content).

Evidence modules (relative to `ashveil-visualizer`): `guassia-selfhost/README.md`, `guassia-selfhost/server.mjs`, `guassia-client/update-policy.cjs`, `guassia-client/README.md`, `gaussia/playtest.js`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 17-01 | Self-hosted world serving | implemented | Serve a packaged runtime. | Preview serves a trusted website export with optional voice; operator supplies internet HTTPS/network setup. |
| 17-02 | Voice and presence | implemented | Connect participants in a room. | Up to ten-person WebRTC voice/presence preview; this is not Mumble protocol compatibility. |
| 17-03 | Authoritative multiplayer | missing | Synchronize shared game state. | Server-side simulation, ownership, replication and reconciliation are not implemented by voice/presence. |
| 17-04 | Windows application packaging | partial | Bundle runtime and dependencies. | Installer preview exists; unsigned status and isolated native QA are not clean-machine fleet compatibility. |
| 17-05 | macOS and Linux application builds | missing | Package per-platform executables. | Source/server portability is not a native installer; need actual builds, signing where applicable and launch QA. |
| 17-06 | Application updates | partial | Verify and apply new releases. | Update policy/download code exists; trusted distribution and automatic installation need end-to-end evidence. |
| 17-07 | Runtime diagnostics | partial | Measure failures and performance. | Input mode, room, loading failures and CPU plus awaited-renderer duration are exposed; real GPU timing/VRAM remain unavailable. |
| 17-08 | Automated visual and performance QA | partial | Detect regressions against fixtures. | Unit/native/browser fixtures exist; add fixed-path image comparisons, hardware profiles and p50/p95 latency before claims. |

### 18 Additional manual domains and research

Sources: [Blender 5.2 LTS manual index](https://docs.blender.org/manual/en/5.2/index.html) · [Unreal Engine documentation](https://dev.epicgames.com/documentation/en-us/unreal-engine) · [Working with Content](https://dev.epicgames.com/documentation/en-us/unreal-engine/working-with-content-in-unreal-engine) · [Visuals and rendering](https://dev.epicgames.com/documentation/en-us/unreal-engine/designing-visuals-rendering-and-graphics-with-unreal-engine).

Evidence modules (relative to `ashveil-visualizer`): `docs/ROADMAP.md`, `ENGINE-ARCHITECTURE.md`, `gaussia/BUILD-STATUS.md`.

| ID | Capability | Baseline | Reference operation | Gaussian implementation or next step |
| --- | --- | --- | --- | --- |
| 18-01 | Grease Pencil and 2D authoring | missing | Draw and animate layered strokes. | A future stroke-to-Gaussian path should remain optional; no current 2D animation suite. |
| 18-02 | XR and virtual production | missing | Render tracked immersive viewpoints. | Requires per-eye rendering, device input, latency measurement and calibration beyond the ordinary browser camera. |
| 18-03 | Hair and groom systems | missing | Author and animate strand detail. | Represent strands as anisotropic Gaussian chains with hierarchical density and bindings; test transparency cost early. |
| 18-04 | CAD and design interchange | missing | Import structured design scenes. | Support declared subsets and unit/material mapping; conversion needs provenance and error reporting. |
| 18-05 | Neural or ML tooling | missing | Run model-assisted content workflows. | Any optional inference must expose model/license/data requirements; ordinary Gaussian editing remains independent of retraining. |
| 18-06 | Render dependency graph and RHI | partial | Separate render work from hardware APIs. | Renderer bridge separates world data from Spark, but a production multi-backend Vulkan/DX12/Metal RHI is not present. |
| 18-07 | Distributed production and review | missing | Coordinate large teams and jobs. | Asset review, farm queues and remote collaboration require services beyond a local browser draft. |
| 18-08 | Data-driven content tools | partial | Inspect and transform structured content. | Validated JSON is present; a searchable asset spreadsheet, dependency graph and bulk editor are not. |

## Prioritized implementation gates

| Gate | Deliverable | Acceptance evidence |
| --- | --- | --- |
| P0 Trustworthy editing | External local project save/open, dependency packing, empty open-ground default, clear dirty/saved states. | A fresh profile reopens a project with identical asset/audio hashes, editable rules and transforms; canceled/corrupt opens leave current work unchanged. |
| P1 Camera and game slice | First-person, third-person and fixed gameplay modes; independent editor views; optional goal-based story. | The same exported world plays in all chosen modes with working collision, pause, touch and restart. |
| P2 Ten-asset quality review | Tree, character-like figure and varied detailed props with actual Gaussian datasets, 4K stills and close inspection. | Owner evaluates each asset; report view coverage, colors, thin structures, halos and stability. Do not substitute a generated beauty image for an engine render. |
| P3 Reusable splat asset editing | Stable Gaussian IDs, sparse layers, masks, local brushes, semantic selection and reusable prefab references. | Base hashes unchanged after ordinary edits; save/open/export preserve layers and exact visual results. |
| P4 Motion and physics | General skeleton/clip bindings, one articulated asset, controller collision and rigid-body proxies. | Covariance follows deformation, restart is deterministic, and scene editing does not retrain or rewrite whole assets. |
| P5 Material fidelity | Explicit radiance versus relightable classes, normals/material attributes, direct light and shadow prototype. | Compare moving-light results, capture baked-light failure cases, preserve attributes through import/export. |
| P6 Large worlds | Spatial chunk indexing, async streaming, projected-error LOD, residency eviction and instanced submission. | Traverse a world larger than RAM/VRAM budgets with recorded stalls, allocations, bytes, p50/p95 frame time and visual-error checks on named hardware. |
| P7 General engine authoring | Typed visual scripts, custom components, UI assets, animation graphs and creator-facing debugging. | A non-music first/third-person game authored entirely through documented tools, with portable project files. |
| P8 Distribution | Reproducible signed platform builds, trusted updates, authoritative multiplayer and isolated creator build jobs. | Clean-machine native launches and rollback/update tests; live account/entitlement/delivery evidence separately from source code. |

## Minimum fidelity fixture set

Use a 4K tree with thin branches and leaf overlap; a close masked character with fingers/joints; a thin open door; an arch with a walkable opening; a small readable sign; rough stone; reflective-looking metal; foliage clusters; a repeated prop field; and a scene crossing a streaming boundary. Record source hashes, source/preview counts, camera projection and distance, field of view, renderer build, color settings, output size, browser/device and warm/cold load state. Inspect stills and a slow orbit/walk. A single screenshot cannot prove temporal stability, all-angle completeness, articulation or frame rate.

## Maintenance

The accompanying JSON is the machine-readable source inventory. Each row has stable ID, documented comparison operation, current status, Gaussian adaptation, source IDs and evidence paths. On a change, update the relevant row only after verifying the workflow, append the public changelog through the normal release process, and retain the baseline date. Current concurrently developed changes must be recorded as a later checkpoint rather than silently retroactively counted here. No promise is made to reproduce every protected implementation, interface or branded technology.

## Source registry and access notes

- **B-INDEX:** [Blender 5.2 LTS manual index](https://docs.blender.org/manual/en/5.2/index.html) — checked 2026-09-24. Official indexed content inspected; some direct category requests returned 402/challenge, so this is not a full manual crawl.
- **B-FILES:** [Blender file workflows](https://docs.blender.org/manual/en/latest/files/blend/index.html) — checked 2026-09-24. Official search-indexed current section inspected.
- **B-PACK:** [Packed data](https://docs.blender.org/manual/nl/5.2/files/blend/packed_data.html) — checked 2026-09-24. Official 5.2 page inspected; relevant text available in English on Dutch locale.
- **B-OBJECT:** [Object and object-data separation](https://docs.blender.org/manual/en/latest/scene_layout/object/introduction.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-TRANSFORM:** [Object transforms](https://docs.blender.org/manual/en/latest/scene_layout/object/editing/transform/introduction.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-SURFACE:** [Surface authoring](https://docs.blender.org/manual/en/latest/modeling/surfaces/index.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-SCULPT:** [Sculpting introduction](https://docs.blender.org/manual/en/latest/sculpt_paint/sculpting/introduction/index.html) — checked 2026-09-24. Official current indexed section inspected.
- **B-PAINT:** [Color attribute painting](https://docs.blender.org/manual/en/latest/sculpt_paint/sculpting/introduction/painting.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-MOD:** [Modifier stack](https://docs.blender.org/manual/en/latest/modeling/modifiers/introduction.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-NODES:** [Geometry Node Editor](https://docs.blender.org/manual/en/latest/editors/geometry_node.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-INSTANCES:** [Split to Instances](https://docs.blender.org/manual/en/5.2/modeling/geometry_nodes/geometry/operations/split_to_instances.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-ANIM:** [Animation and rigging](https://docs.blender.org/manual/en/5.2/animation/index.html) — checked 2026-09-24. Official current indexed section inspected.
- **B-ANIM-INTRO:** [Animation operation](https://docs.blender.org/manual/en/5.2/animation/introduction.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-RENDER:** [Rendering systems](https://docs.blender.org/manual/en/5.2/render/index.html) — checked 2026-09-24. Official current indexed section inspected.
- **B-OUTPUT:** [Render output](https://docs.blender.org/manual/en/5.2/render/output/properties/output.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-TRACK:** [Motion tracking](https://docs.blender.org/manual/en/5.2/movie_clip/tracking/introduction.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-VIDEO:** [Video editing workflows](https://docs.blender.org/manual/en/latest/video_editing/edit/index.html) — checked 2026-09-24. Official current indexed content inspected.
- **B-UI:** [Interface preferences](https://docs.blender.org/manual/de/5.2/editors/preferences/interface.html) — checked 2026-09-24. Official 5.2 page inspected; relevant text available in English on German locale.
- **U-INDEX:** [Unreal Engine documentation](https://dev.epicgames.com/documentation/en-us/unreal-engine) — checked 2026-09-24. Current official index identifies Unreal Engine 5.8.
- **U-CONTENT:** [Working with Content](https://dev.epicgames.com/documentation/en-us/unreal-engine/working-with-content-in-unreal-engine) — checked 2026-09-24. Official current page inspected.
- **U-WORLD:** [Building Virtual Worlds](https://dev.epicgames.com/documentation/en-us/unreal-engine/building-virtual-worlds-in-unreal-engine) — checked 2026-09-24. Official current page inspected; overview rather than every subpage.
- **U-GAMEPLAY:** [Gameplay Systems](https://dev.epicgames.com/documentation/en-us/unreal-engine/gameplay-systems-in-unreal-engine) — checked 2026-09-24. Official current page inspected including listed subsystem directory.
- **U-CAMERA:** [Cameras](https://dev.epicgames.com/documentation/en-us/unreal-engine/cameras-in-unreal-engine) — checked 2026-09-24. Official current page inspected.
- **U-BLUEPRINT:** [Blueprints Visual Scripting](https://dev.epicgames.com/documentation/en-us/unreal-engine/blueprints-visual-scripting-in-unreal-engine) — checked 2026-09-24. Official current page inspected.
- **U-RENDER:** [Visuals and rendering](https://dev.epicgames.com/documentation/en-us/unreal-engine/designing-visuals-rendering-and-graphics-with-unreal-engine) — checked 2026-09-24. Official current page inspected including subsystem directory.
- **U-ANIM:** [Animating characters and objects](https://dev.epicgames.com/documentation/en-us/unreal-engine/animating-characters-and-objects-in-unreal-engine) — checked 2026-09-24. Official current page inspected.
- **U-PARTITION:** [World Partition](https://dev.epicgames.com/documentation/en-us/unreal-engine/world-partition-in-unreal-engine) — checked 2026-09-24. Official current page inspected.
- **U-UI:** [Creating user interfaces](https://dev.epicgames.com/documentation/en-us/unreal-engine/creating-user-interfaces-with-umg-and-slate-in-unreal-engine) — checked 2026-09-24. Official current page inspected; subsystem index.
- **U-AUDIO:** [Audio](https://dev.epicgames.com/documentation/en-us/unreal-engine/audio-in-unreal-engine) — checked 2026-09-24. Official current landing page inspected; no claim to enumerate every audio tool.
- **U-QA:** [Testing and optimizing content](https://dev.epicgames.com/documentation/en-us/unreal-engine/testing-and-optimizing-your-content) — checked 2026-09-24. Official current overview inspected.
- **U-PACKAGE:** [Packaging projects](https://dev.epicgames.com/documentation/en-us/unreal-engine/packaging-your-project) — checked 2026-09-24. Official current page inspected.