Collision Files Guide 2026 — YBN Editing for GTA 5

Collision Files Guide — YBN Editing in GTA 5 (2026)

Collision files determine where players and vehicles can physically interact with the game world. Without proper collision meshes, characters fall through floors, vehicles pass through walls, and objects become untouchable. This 2026 guide covers YBN collision file editing for creating solid, interactive environments in your GTA 5 mods.

What Are YBN Files

YBN (Bound) files contain collision geometry — simplified 3D shapes that define physical boundaries separate from visual models. While a building's visual model (YDR) might have thousands of polygons for detail, its collision mesh (YBN) uses only hundreds of simple shapes for efficient physics calculations. GTA 5 uses several collision types: BoundBox (simple box), BoundSphere, BoundCapsule, BoundGeometry (complex mesh), and BoundComposite (multiple shapes combined).

Editing Collisions with CodeWalker

CodeWalker is the primary tool for YBN editing. Open any YBN file to view and modify its collision geometry, material properties, and flags. Each collision surface has a material type (concrete, metal, glass, water, etc.) that determines sound effects, bullet impact particles, and vehicle tire interactions. You can add, remove, or reshape collision polygons, adjust bounding boxes, and set procedural properties that control how NPCs and vehicles interact with the surface.

Creating Collisions for Custom Models

When creating collisions for new models, follow these principles: keep collision geometry as simple as possible (use boxes and spheres where feasible), ensure complete coverage with no gaps that characters could fall through, match the general shape of the visual model without duplicating its detail, and set appropriate material flags. For buildings, create separate collision layers for walls, floors, ceilings, and stairs. For vehicles, collision bounds must match the chassis shape for realistic crash physics.

Common Collision Issues and Fixes

Falling through floors indicates missing or improperly oriented collision polygons — check that face normals point outward. Invisible walls blocking movement mean collision extends beyond the visual model — reduce collision bounds to match. Objects that cannot be interacted with are missing collision entirely — create a YBN matching the object dimensions. Performance issues from collision arise when using overly complex geometry — simplify by replacing detailed meshes with primitive shapes wherever possible.