Bounds and Audio
Two small sections that are easy to forget, plus how to get the mod into the game and check it.
01. Bounds
Bounds is the box the game uses to decide where the vehicle fits: a size and a box origin offset, both in centimetres.
It does not resize itself when you swap meshes. A mesh swap changes what is drawn; the box stays as the original vehicle described it. So a reskin that makes the body noticeably longer, wider or taller needs a manual pass here, or the vehicle will park with a gap around it, clip into things, or refuse to fit somewhere it visually should.
Setting it
- Open Bounds.
- Click Show Bounds Box to draw the current box in the preview.
- Adjust size until the box wraps your body.
- Use the origin offset to re-centre it if your mesh pivot is not in the middle of the vehicle.
Leaving it alone is fine when your reskin is roughly the original silhouette - a different-looking sedan of the same size does not need new bounds.
02. Audio
The Audio section sets three sounds:
| Sound | When it plays |
|---|---|
| Main | The engine, while driving. |
| Spawn | When the vehicle appears. |
| Despawn | When it is put away. |
Each is a MetaSound asset.
⚠️ Audio is shared by the vehicle template, not by the vehicle. Vehicles that share a template share their audio, so changing the engine sound on one can change it for its siblings.
Duplicate mods handle this for you. A new vehicle starts out sharing its source's template, and the first time you change a sound it automatically gets its own. Your engine note never leaks back onto the vehicle you copied.
For an Override mod that wants its own audio, split the template off deliberately before you start.
Splitting the template also registers it for purchase. The game looks up a vehicle's purchase rules by template, so a dedicated template needs its own entry or the vehicle cannot be bought - the shop button greys out with an unrelated message. The workspace creates that entry for you, copying the original's age requirement and sounds.
A sound showing as None is not always empty. If the asset is not
one ModKit ships, the field displays None while the original path is
still there underneath. Setting a different sound replaces it; leaving
it alone keeps what was there. You will not lose a sound by opening the
section and closing it again.
03. Saving, packaging and testing
Editing the workspace changes data in the project. Two more steps get it into the game.
- Save the project.
- Package it. This builds the mod and writes it out where the game can load it.
- Launch the game and check the vehicle.
What to check in game, in order
| Check | Why this one |
|---|---|
| It appears in the Dream Car app with a thumbnail | Catches a missing representative-colour icon |
| It looks right parked up close | The mesh slots |
| It still looks right as traffic drives past | Catches an unreplaced distant mesh |
| A Zoi can board and sits correctly | Seats after a body swap |
| The trunk and other interactions are reachable | Interaction points after a body swap |
| Doors and wipers move | Animation, and Mesh Name in particular |
| It parks without odd gaps or clipping | Bounds |
If something is wrong, the section pages each have a Common issues and fixes table for that area.
04. Common issues and fixes
| Issue | Cause | Fix |
|---|---|---|
| Vehicle parks with a large gap around it | Bounds still describe the original body | Set size in Bounds |
| Vehicle clips into walls or other objects | Bounds smaller than the new body | Same |
| Bounds box is off to one side | Mesh pivot is not centred | Use the box origin offset |
| Engine sound changed on a different vehicle | Template shared with that vehicle | Split off a private template |
Sound shows None after opening the section | Asset not shipped with ModKit | Display only - the original is intact |
| Changes are not in the game | Not packaged since the last edit | Save, then package again |
05. Chapter summary
| Checklist | Done |
|---|---|
| Does the bounds box wrap the new body? | ✅ |
| If I changed audio, is the template private to this vehicle? | ✅ |
| Did I package after the last edit? | ✅ |
| Did I check the vehicle in traffic, not just parked? | ✅ |
06. What the MCP tools cover
| Tool | Use |
|---|---|
modkit_set_vehicle_dimensions | Bounding size and box origin offset. |
modkit_set_vehicle_audio | Main, spawn and despawn sounds. Omitted fields keep their current value. |
modkit_create_vehicle_template | Split off a private template before a template-level edit such as audio. |
modkit_package | Build the mod. |
07. Data reference
- VehicleTemplate - the shared template audio and dimensions belong to.
- FB1VehicleAssetDescription - the vehicle's physical dimensions.
- ObjectBP - where the bounding box is stored.