Inspired by Pokémon Snap (1999). VLM pilots a drone through 3D world to locate and identify creatures.

%%{init: {'theme': 'base', 'themeVariables': { 'background': '#ffffff', 'primaryColor': '#ffffff'}}}%%
flowchart LR
    subgraph Controller["**Controller** (Rust)"]
        C[Orchestration]
    end

    subgraph VLM["**VLM** (OpenRouter)"]
        V[Vision-Language Model]
    end

    subgraph Simulation["**Simulation** (Zig/raylib)"]
        S[Game State]
    end

    C -->|"screenshot + prompt"| V
    C <-->|"cmds + state<br>**UDP:9999**"| S

    style Controller fill:#8B5A2B,stroke:#5C3A1A,color:#fff
    style VLM fill:#87CEEB,stroke:#5BA3C6,color:#1a1a1a
    style Simulation fill:#4A7C23,stroke:#2D5A10,color:#fff
    style C fill:#B8864A,stroke:#8B5A2B,color:#fff
    style V fill:#B5E0F7,stroke:#87CEEB,color:#1a1a1a
    style S fill:#6BA33A,stroke:#4A7C23,color:#fff

The simulation generates procedural terrain and spawns creatures (cat, dog, pig, sheep) for the drone to discover. It handles drone physics and collision detection, accepting 8 movement commands plus identify and screenshot. The Rust controller captures frames from the simulation, constructs prompts enriched with position and state data, then parses VLM responses into executable command sequences. The objective: locate and successfully identify 3 creatures, where identify succeeds when the drone is within 5 units of a target.

I gave 7 frontier LLMs a simple task: pilot a drone through a 3D voxel world and find 3 creatures.

Only one could do it.

Is this a rigorous benchmark? No. However, it's a reasonably fair comparison - same prompt, same seeds, same iteration limits. I'm sure with enough refinement you could coax better results out of each model. But that's kind of the point: out of the box, with zero hand-holding, only one model figured out how to actually fly.

The core differentiator wasn't intelligence - it was altitude control. Creatures sit on the ground. To identify them, you need to descend.

• Gemini Flash: Actively adjusts altitude, descends to creature level, identifies
• GPT-5.2-chat: Gets close horizontally but never lowers
• Claude Opus: Attempts identification 160+ times, never succeeds - approaching at wrong angles
• Others: Wander randomly or get stuck

This left me puzzled. Claude Opus is arguably the most capable model in the lineup. It knows it needs to identify creatures. It tries - aggressively. But it never adjusts its approach angle.

Run 13 (seed 72) was the only run where any model found 2 creatures. Why? They happened to spawn near each other. Gemini Flash found one, turned around, and spotted the second.

In most other runs, Flash found one creature quickly but ran out of iterations searching for the others. The world is big. 50 iterations isn't a lot of time.

This was the most surprising finding. I expected:

• Claude Opus 4.5 (most expensive) to dominate
• Gemini 3 Pro to outperform Gemini 3 Flash (same family, more capability)

Instead, the cheapest model beat models costing 10x more.

What's going on here? A few theories:

1. Spatial reasoning doesn't scale with model size - at least not yet
2. Flash was trained differently - maybe more robotics data, more embodied scenarios?
3. Smaller models follow instructions more literally - "go down" means go down, not "consider the optimal trajectory"

I genuinely don't know. But if you're building an LLM-powered agent that needs to navigate physical or virtual space, the most expensive model might not be your best choice.

Anecdotally, creatures with higher contrast (gray sheep, pink pigs) seemed easier to spot than brown-ish creatures that blended into the terrain. A future version might normalize creature visibility. Or maybe that's the point - real-world object detection isn't normalized either.

Before this, I tried having LLMs pilot a real DJI Tello drone.

Results: it flew straight up, hit the ceiling, and did donuts until I caught it. (I was using Haiku 4.5, which in hindsight explains a lot.)

The Tello is now broken. I've ordered a BetaFPV and might get another Tello since they're so easy to program. Now that I know Gemini Flash can actually navigate, a real-world follow-up might be worth revisiting.

This is half-serious research, half "let's see what happens."

• The simulation has rough edges (it's a side project, not a polished benchmark suite)
• One blanket prompt is used for all models - model-specific tuning would likely improve results
• The feedback loop is basic (position, screenshot, recent commands) - there's room to get creative with what information gets passed back
• Iteration limits (50) may artificially cap models that are slower but would eventually succeed

gh repo clone kxzk/snapbench
cd snapbench

# set your API key
export OPENROUTER_API_KEY="sk-or-..."

# terminal 1: start the simulation (with optional seed)
zig build run -Doptimize=ReleaseFast -- 42
# or
make sim

# terminal 2: start the drone controller
cargo run --release --manifest-path llm_drone/Cargo.toml -- --model google/gemini-3-flash-preview
# or
make drone

# runs all models defined in bench/models.toml
uv run bench/bench_runner.py
# or
make bench