Custom MLO Interiors: From Blender to Server

Building your own MLO from scratch is the most ambitious thing you can do for a FiveM server. It is also a months-long project for most people.

The toolchain

You need: Blender for modeling, OpenIV for opening GTA assets, CodeWalker for placing things in the world, and Sollumz (a Blender add-on) for exporting in formats GTA understands. All free, all powerful, all with steep learning curves.

The workflow at 30,000 feet

Model the interior in Blender. Texture it. Export with Sollumz to .ydr / .ydd. Build collision meshes (separate from the visual model). Place portals where doors and windows are. Compile a .ytyp linking the interior. Generate a .ymap that places it in the world. Test in CodeWalker. Pack as a FiveM resource.

The hard parts

Collision is the single most painful part. Your visual model can look perfect, but if your collision mesh is misaligned by 5cm players will fall through floors. Spend more time on collision than you think you need to.

Lighting is the second hard part. GTA uses pre-baked lighting via .ymt files; getting interiors to look correct in dim conditions takes iteration.

Realistic time

A simple two-room interior: ~40 hours for an experienced modder. A full house: 80–120 hours. A multi-floor business: 200+ hours. Plan accordingly, or pay a creator who has already done the reps.

Wrapping up

If you are building one MLO to learn the pipeline, start tiny — a single one-room shop. Once you have that working end-to-end, the next one will take half the time.