ss14-transform-physics

name	ss14-transform-physics
description	Work with SS14 transforms, coordinates, grids, maps, anchoring, containers, movement, collision, fixtures, physics bodies, thrown entities, or spatial queries.

SS14 Transform And Physics

Use this skill when a change moves entities, changes collision, depends on map/grid coordinates, or edits physics behavior.

Spatial code is fragile because transform, map grids, containers, and physics all interact. Prefer the established entity systems over direct component mutation.

Workflow

1. Choose the right coordinate space.

• Use entity coordinates for relative positions and map coordinates for world/map-space decisions.
• Convert deliberately at system boundaries; do not compare coordinates from different maps or grids without conversion.
• Handle nullspace, deleted entities, and entities leaving PVS or containers.

2. Use systems for spatial mutations.

• Prefer SharedTransformSystem, SharedPhysicsSystem, container systems, and movement systems over direct field writes.
• Anchoring, parenting, and grid changes should go through the existing APIs so broadphase, fixtures, and dirty state stay coherent.
• Do not make shared predicted movement depend on server-only systems.

3. Keep collision data data-driven.

• Prefer prototype fixture and body settings when content should tune collision.
• If code changes fixture masks, layers, density, or collision state, check the nearby component and prototype patterns.

4. Respect server authority and prediction.

• Server systems own authoritative physics outcomes.
• Shared predicted code may provide local responsiveness, but must converge with server state.
• Avoid random impulses or non-deterministic client-only motion in predicted paths.

5. Validate with focused coverage.

• Build affected shared/server/client projects.
• For movement or collision bugs, prefer an in-game pass or a targeted integration test when practical.

Reference Map

• ../ss14-prediction/SKILL.md
• ../ss14-netcode/SKILL.md
• ../ss14-standard-optimizations/SKILL.md
• ../ss14-ecs-systems/SKILL.md

Good File Anchors

• Content.Shared/**/Movement/**
• Content.Shared/**/Physics/**
• Content.Server/**/Movement/**
• Content.Server/**/Physics/**
• Resources/Prototypes/**

Common Pitfalls

• Mutating transform or physics component fields directly.
• Mixing map and entity coordinates without an explicit conversion.
• Forgetting containers, anchoring, or grid changes when moving entities.
• Adding client-only movement that cannot reconcile with server state.