Live UE Scene Bridge workflow — UE Editor + Web UI + AI generation results

Live UE Scene Bridge

Natural-language scene control, generative service integration, and processing feedback

Internal R&D PoC · Demo stage · C++ · FastAPI · Next.js

Problem

Cinev Studio had character and camera workflows, but controls for lighting, asset placement, weather, and time of day were still limited. I built a PoC for controlling these through natural language and passing the scene into image and video generation services.

Solution

I connected natural-language scene control and external generative services using the plugin’s existing Python–C++ JSON bridge. Cesium sets the location and UDS controls time and weather; an Unreal viewport capture then feeds into image and video generation. My focus was defining processing states across C++, Python, and TypeScript and communicating progress to users.

Usage Examples

"Show me downtown Tokyo"

"Go to San Francisco"

"Set the time to 6 PM"

"Give me warm tones"

"Set up a cold noon scene"

3-Layer Architecture

Web UI / CLI → HTTP:34115 → FastAPI + NLP (Claude/Gemini)
                                    ↓
              ┌──────────────┬──────────────┬──────────────┐
              │ UE C++ Plugin│ Nano Banana  │ Veo-3        │
              │ TCP:55557    │ Image Gen    │ Video Gen    │
              └──────────────┴──────────────┴──────────────┘

① Web UI (Next.js) / CLI — frontend where users input natural language

② FastAPI — converts natural language to JSON commands. Users choose Claude or Gemini based on their own API key

③ UE C++ Plugin — receives JSON commands via TCP socket and executes in editor. Nano Banana transforms UE HighResShot via i2i, Veo-3 generates video directly from the result

Core — Cesium + UDS Integration

Cesium and Ultra Dynamic Sky set the location, time, weather, and mood; Nano Banana turns the scene into a concept image. I focused on defining the status passed between services and showing users which step was currently running.

AI style transformation result — post-apocalyptic

Style transformation result — "Give me a post-apocalyptic mood"

Full i2i pipeline — style selection and transformation in Web UI

i2i pipeline in Web UI

Roblox Integration — Business Demo

I imported FBX assets through the Roblox API into UE, placed characters on generated backgrounds, and produced images and videos with Nano Banana and Veo-3. This internal demo showed the CEO and planning team how the workflow could be used.

Roblox character import placed on background + AI transformation

Roblox character placed on generated background

Processing Status Feedback

A request to give the current Unreal scene the atmosphere of another era passes through capture, transfer, generation, and waiting for a response. I defined status information across C++, Python, and the TypeScript UI so users could understand what they were waiting for.

StageWorkflow
CaptureC++ captures the Unreal viewport
TransferPass the capture to Python
Generate / WaitSubmit to the image generation API and wait
ResultPresent the generated result in the UI

Refining LLM Inputs and Calls

After the workflow was in place, I refined LLM inputs and call structure. I centralized LLM processing in Python to reduce duplicate calls and simplified parameter-validation instructions, decision branches, examples, and injected context. For image transformation, I compared prompt length with clarity while considering instructions needed to preserve composition and control transformation strength.

For CJK asset-name translation, I also applied batching, deduplication of shared names, and concise input/output formatting.

Deciding what to adopt next

Lighting and asset-placement controls were planned as follow-up features to fill gaps in the product. Character–environment interaction was also a later task. In a separate snow and puddle interaction experiment, results varied between runs; I deferred adoption because consistent behavior could not be secured within the remaining schedule.

Result

Category Result
Outdoor Scene SetupOne-step composition of location + time + weather + mood via natural language
i2i PipelineScene to concept/mood transformation via Nano Banana
Service Integration4 services (UE, Nano Banana, Veo-3, Roblox)
AudienceDemo for CEO, planners, team leads — POC
OutcomeCompleted internal demos for the CEO, planners, and team leads. Follow-up development was deferred due to business priorities; the work remained a PoC without production use.
Early prototype — MCP Frontend + UE viewport

Early prototype — real-time UE viewport control via natural language input

PMX to VRM Pipeline Matcap Painter