During ISP-HK, every team creates their own design proposal by CAD/BIM such as SketchUP. In this tutorial, show how to import SketchUP model into Unity, and how to set walk-through in Unity. For this, prepare SketchUP model at the 3D Warehouse.
Search "Rameez Arain" and download the "Interior" model by "SketchUP 2018" format.
If you prepare 3D model by Autodesk Revit, please export by .fbx file format on Revit. And Import the .fbx file on Unity.
If you need a human model, you can use my friend, Mr. Andoh.
https://sketchfab.com/3d-models/andou-be954b87f1b24fdcbe94b85cbeecad44
Project name: SketchUP_1
Template: 3D
[Assets]-[Import New Asset...]
Select the SketchUP model such as "Untitled_2018.skp".
[Window]-[Rendering]-[Lighting Settings]
[Environment Lighting]-[Source] Skybox->Gradient
[GameObject]-[3D Object]-[Cube]
Select the Cube, Set Scale as "X=50, Y=1, Z=50", and Position as "Y=-0.5".
[Window]-[Asset Store]
Search "Standard Assets" on the "Asset Store" tab
Click "Import" button, then click "import" button again.
In the "Project" folder, Select [Assets]-[Standard Assets]-[Characters]-[FirstPersonCharacter]-[Prefabs]-[FPSController]
Drag the "FPSController" into Hierarchy
Delete the default "Main Camera" in Hierarchy
Select the building model (Untitled_2018), Set the "Scale" as "X=2.54, Y=2.54, Z=2.54".
Select "Cube" in the Hierarchy, Click [Component]-[Physics]-[Mesh Collider]
Select building components that needs collision detection such as floor and wall, Click [Component]-[Physics]-[Mesh Collider]
Click the "Play" button
Rotate using mouse, Move using arrow keys
Materials and textures are not generally transferred from SketchUP to Unity, Set them on Unity again.