Guidebook Modelling Overview

Bring your own 3D models into Data Center as buyable hardware or static deco. OBJ only, static only — no animation, no rigging, no skinned meshes. If you can export a clean static OBJ from Blender, you can do this track.

Pipeline code: GregObjImport (validation) → GregCustomItems (vanilla ModLoader loading) → GregModPack (DTOs) → shop/cart/save. Lua surface: greg.items. Full spec tables: Guidebook Modelling Shop Item and Guidebook Modelling Static Item.

The pipeline (same for every item)

Blender (or any modeller)
  → model.obj (≤ 64 MB, must import with vertexCount > 0)
  → mod folder: model.obj + texture.png + icon.png
  → mesh pre-check (GregObjImport: .obj only, no ".." escapes, vanilla ObjImporter trial)
  → DTO (ShopItem / StaticItem: names, files, scale, size, mass, type)
  → vanilla ModLoader.LoadShopItem / LoadStaticItem
  → shop ("HL Mods") or static placement, prefabs via GetPrefab

Every step is best-effort with a clear log line ([gregCore][Mods] ObjImport: / CustomItems:). A failed pre-check aborts registration with a warning instead of a silent vanilla drop — read the log first when an item is missing.

Static only — what that means

• The importer is the vanilla Il2Cpp.ObjImporter.ImportOBJ: pure triangle soup. Armatures, animations, shape keys, and skinning do not survive — strip them before export (see Guidebook Modelling OBJ Blender).
• Physics comes from data, not the mesh: Mass, ColliderSize, ColliderCenter (and IsKinematic for statics) in the DTO. The mesh is visual; the collider is numbers you provide.
• Placement behaviour (rack units via SizeInU, buying via shop, spawning via vanilla loader) is game-owned; your model rides along.

The two item kinds

	Shop item	Static item
Lua	greg.items.register_shop_item(subfolder, spec)	greg.items.register_static_item(subfolder, spec)
C#	GregCustomItems.RegisterShopItem(folderPath, folderName, dto)	GregCustomItems.RegisterStaticItem(folderPath, folderName, dto)
DTO	GregModPack.ShopItem (price, xp, size_u, mass, type, icon…)	GregModPack.StaticItem (scale, position, rotation, kinematic…)
Shows up	Shop, “HL Mods” section, cart, checkout	Static/deco placement via the vanilla loader
Needs	Unique high ID (100, 1000/2000/3000, 9001+), valid ObjectType	A pack folder + model file; no ID, no price

Spec keys accept snake_case or PascalCase (Lua aliases + case-insensitive DTO binding — verified in LuaItemsModule).

What you need

• Blender (or equivalent) + this track’s export checklist (Guidebook Modelling OBJ Blender).
• A text editor (Lua) or .NET 6 SDK (C#) — same prerequisites as the other tracks (Guidebook Prerequisites).
• Patience for one test loop: export → register → check log → look in-game → adjust scale → repeat.

Track order

1. Guidebook Modelling OBJ Blender — the OBJ contract + export checklist (read first, saves hours).
2. Guidebook Modelling Shop Item — buyable hardware end-to-end.
3. Guidebook Modelling Static Item — deco/statics end-to-end.
4. Guidebook Modelling Troubleshooting — every failure mode with log line + fix.