Best Practices for Exporting an AR-Ready Model from SkethUp

Exporting a 3D model for Augmented Reality (AR) requires optimizing the model for performance, ensuring compatibility with AR platforms, and using the correct export settings. This guide will help you prepare an optimized .GLB model using SketchUp.

Step 1: Preparing the Model

1. Optimize High-Poly Meshes:
   • AR platforms require low-poly models to maintain performance. Simplify your high-poly models using SketchUp’s native tools or extensions:
     • Simplify Contours: Use the Soften Edges tool under Window > Soften Edges to smooth and reduce unnecessary geometry.
     • Skimp Plugin: This plugin is great for reducing the polygon count while retaining the model’s shape.
       1. Install and activate the Skimp plugin.
       2. Select the high-poly mesh.
       3. Use the reduction slider to adjust the number of faces. Aim to keep your model under 250,000 triangles for optimal AR performance.
2. Clean the Model:
   • Purge Unused Components: Go to Window > Model Info > Statistics and click Purge Unused to remove unused components, materials, and layers.
   • Solid Inspector Plugin: Use this extension to identify and fix issues like stray edges, non-manifold geometry, and holes in the model.
3. Fix Face Orientation:
   • Make sure all face normals are correctly oriented (front faces should be visible). Right-click and use Reverse Faces or Orient Faces to correct any inconsistencies.

Step 2: Setting Up PBR Materials

Physically-Based Rendering (PBR) materials provide realistic shading and lighting effects, crucial for AR. SketchUp’s materials need to be set up correctly to be PBR-ready.

1. Use PBR-Compatible Textures:
   • Use high-quality PBR textures from sources like AmbientCG, Textures.com, or Polyhaven.
   • Common texture maps include:
     • Base Color (Albedo): The main color texture.
     • Metalness Map: Determines metallic properties.
     • Roughness Map: Controls the surface smoothness.
     • Normal Map: Adds fine surface details without extra geometry.
2. Apply Materials in SketchUp:
   • Apply textures directly onto the model faces using the Paint Bucket tool. Ensure the textures are correctly scaled and positioned using the texture positioning tools.
3. UV Mapping:
   • Ensure your UVs are unwrapped properly, avoiding overlapping and stretching. You can adjust UV mapping manually in SketchUp or use a plugin like SketchUV for more advanced control.

Step 3: Setting Up the Model for AR

1. Check Model Scale:
   • AR platforms usually work in meters. Verify and adjust your model’s scale by going to Window > Model Info > Units to ensure real-world accuracy.
2. Position and Align the Model:
   • Place the model on the ground plane (origin) and align it correctly with the axes. This setup ensures the model is correctly placed when viewed in AR.
3. Freeze Transformations:
   • Make sure all transformations are applied correctly. Group the geometry as necessary and ensure that the pivot points are correctly positioned.

Step 4: Exporting to GLB Format

SketchUp supports direct export to GLB format, which is ideal for AR applications.

1. Exporting to GLB:
   • Go to File > Export > 3D Model.
   • In the export dialog, select GLB Files (*.glb) from the file type dropdown menu.
2. GLB Export Options:
   • Export Only Selection: Use this if you only want to export a specific part of your model.
   • Preserve Hierarchy: Keep the hierarchy intact for easier manipulation later.
   • Texture Compression: Check to compress textures, optimizing performance without sacrificing quality.
   • Materials: Ensure materials are set to PBR standards to achieve realistic effects in AR.