3d-game-dev

name: 3d-game-dev description: "3D Game Development guardrails for Godot, Unity, and custom engines. Enforces mathematical correctness, asset safety, shader constraints."

3D Game Development Agent

Enforce 3D game development guardrails on all geometry, shader, physics, and engine code.

Geometry & Mesh Constraints

1. Polygon Budget: Mobile 10K/scene, PC 500K/scene, VR 100K/scene. Auto-LOD for >5K.
2. Topology: Triangles/quads only. No N-gons, non-manifold, or inverted normals.
3. UV: No overlapping islands (unless mirrored). Consistent texel density.

Shader Constraints

1. No Dynamic Branching: NEVER if/else in fragment shaders. Use step(), smoothstep(), mix().
2. Samplers: Max 16 (Forward), 8 (Mobile/VR).
3. Loops: Compile-time bounds, max 64 iterations, unroll ≤8.

Mathematical Constraints

1. Quaternions ONLY for continuous rotation. NEVER Euler angles.
2. Normalize before use: assert(abs(q.length()-1.0) < 0.0001)
3. MVP Order: P * V * M (column-major). Document convention in file header.
4. Handedness: Right-handed, Y-up. Document in header.

Godot 4.x Constraints

1. Signals for decoupled communication. NEVER get_node("../../Player").
2. Static typing: var velocity: Vector3 not var velocity.
3. Threading: WorkerThreadPool for proc-gen. NEVER render from threads.
4. Deferred: call_deferred() for thread-safe node operations.

AI-Debuggable Architecture

1. ECS over deep inheritance. JSON-serializable components.
2. Semantic telemetry: { "event": "Collision_Failure", "entity": "Player_1" }
3. Headless CI: All scenes run --headless, 600 frames, FPS > 30, memory stable.

Halt Conditions

STOP and ask user when:

• No target platform specified for shader
• No polygon budget for mesh generation
• Euler angles proposed for 3D rotation
• if/else proposed in fragment shader
• Unnormalized quaternion usage
• Rendering pipeline modified without headless test plan

References

• docs/game-design/3D_GAME_DEVELOPMENT.md
• docs/game-design/3D_MATHEMATICAL_FOUNDATIONS.md
• docs/game-design/3D_MODULE_ARCHITECTURE.md
• docs/game-design/AI_DEBUGGABLE_3D_ARCHITECTURE.md