Kitsmith

Engine import: Unity, Unreal, Godot

Every asset is stored in meters with +Y up (the glTF convention). The Package kit button (free) bundles approved assets into a zip laid out for the engine in your kit spec. You can repackage for a different engine at any time.

What is in the package

MyKit/
  README.md            import steps for your engine
  LICENSE.txt          your rights and third-party notices
  AI_DISCLOSURE.txt    what was AI-generated and how
  BuildingPieces/      KS_Wall_2u_Stone.glb, ...
  Props/
  Equipment/
  Characters/          .glb and .fbx, animations embedded
  Textures/            <name>_BaseColor.png, _Normal.png,
                       _Roughness.png, _Metallic.png, _AO.png, _Height.png
  Previews/            PNG thumbnails

The exact layout varies slightly by engine; the README in each package is the reference for that package. Only approved assets are included. File names are consistent across categories so they sort and search predictably. Texture maps are PNG; meshes are GLB, with FBX for characters.

Unity

  1. Unzip into Assets/Kitsmith/<KitName>/. Keep the folder structure; prefab and material setup is easier when categories stay separate.
  2. GLB: install glTFast (com.unity.cloud.gltfast) from the Package Manager. GLB files then import as regular model assets with their PBR materials. FBX: Unity imports FBX natively; use it for characters if you prefer the built-in rig tooling.
  3. Materials: glTFast creates URP, HDRP or Built-in materials depending on your render pipeline. For more control, extract the materials and assign the texture maps from Textures/ to your own Lit shader. Set normal maps to Texture Type Normal map.
  4. Prefabs: drag each building piece into the scene, add a MeshCollider (or a BoxCollider for walls and floors), and save as a prefab. Props usually want a simple Box or Capsule collider.
  5. Characters: select the FBX, open the Rig tab, set Animation Type to Humanoid and Avatar Definition to Create From This Model. Mixamo-style bone names map automatically. Add an Animator Controller and drop in the included clips.
  6. Snapping: set grid snapping to your grid unit. See Modular grid conventions.

Unreal Engine

  1. Import through the Content Browser (Import, or drag and drop). Use FBX for characters. For static meshes, either FBX or glTF works with the built-in Interchange importer.
  2. Scale and axes: leave import uniform scale at 1.0. Unreal is Z-up and uses centimeters; the importer converts from meters and Y-up. A 2 m wall becomes 200 units wide.
  3. Collision: enable Generate Missing Collision for props, or open the Static Mesh editor and add a simplified box collision. For walls and floors, simple box collision is usually enough; use complex-as-simple only for irregular pieces like stairs if needed.
  4. Materials: create one master material with texture parameters for base color, normal, roughness, metallic and AO, then create a Material Instance per Kitsmith material and plug in the maps. Set roughness, metallic and AO textures to linear (sRGB off).
  5. Characters: import as a Skeletal Mesh with Import Animations enabled. The first import creates a Skeleton asset; import further animation FBX files against that same skeleton. To use Unreal’s own animations, set up an IK Rig and IK Retargeter.
  6. Set location grid snap to your grid unit in centimeters and rotation snap to 90 degrees.

Godot 4

  1. Copy the unzipped folder into your project, for example res://kits/<KitName>/. Godot imports GLB natively; no plugin is needed.
  2. Import settings: double-click a GLB to open Advanced Import Settings. Useful options: generate collision per mesh (Physics > Create), extract materials to .tres files so you can edit them, and set a root scale if your project does not use meters.
  3. MeshLibrary for GridMap: create a scene with a plain Node3D root and instance each building piece as a child, each with a StaticBody3D and CollisionShape3D if you want collision. Then use Scene > Export As > MeshLibrary. Assign the library to a GridMap with cell size set to your grid unit, and turn off Cell Center X, Y and Z because pieces pivot at the corner.
  4. Characters: instance the character GLB. Its clips appear in the generated AnimationPlayer. Use an AnimationTree for blending, and set looping on idle, walk and run in the import settings. For clips from other sources, set up a BoneMap with SkeletonProfileHumanoid (see Characters).

Plain glTF

The glTF package contains the same GLB files and texture PNGs without engine-specific notes. Use it for Blender, three.js, Babylon.js, Bevy or any other glTF 2.0 tool.

Troubleshooting

  • Model is 100 times too big or small: an extra import scale was applied. Reset to 1.0.
  • Model lies on its side: a manual axis conversion was added on top of the importer’s own. Remove it.
  • Normal map looks inverted: maps are exported in the OpenGL (Y+) convention used by glTF. In Unreal, enable Flip Green Channel on the normal texture.
  • Textures look washed out: only base color should be sRGB. All other maps are linear.