Best Practices for Exporting an AR-Ready Model from 3ds Max

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 3ds Max.

Step 1: Preparing the Model

1. Optimize High-Poly Meshes:
   • AR applications demand low-poly models to maintain performance. High-poly models should be simplified using 3ds Max modifiers:
     • ProOptimizer Modifier: Use this modifier to reduce the polygon count while maintaining the overall shape of the model.
       • Apply the ProOptimizer modifier to the high-poly mesh.
       • Click "Calculate" to analyze the mesh.
       • Adjust the "Vertex %" or "Face %" to reduce the complexity. Aim to keep the model under 250,000 triangles for AR.
       • Use the “Keep Textures” option to ensure the UVs remain intact.
     • Decimate Modifier: An alternative for reducing polygon count without losing much detail.
       • Control the reduction by adjusting the parameters to keep the shape as close as possible to the original.
2. Check and Fix Normals:
   • Ensure that all normals are facing outward. Use the "Normal" modifier to flip any incorrect normals, as this will prevent shading issues in AR.
3. Clean the Model:
   • Remove unnecessary elements like unused vertices, hidden objects, or dummy nodes.
   • Use the "Reset XForm" tool to reset the transformations of the objects.

Step 2: Setting Up PBR Materials

Physically-Based Rendering (PBR) materials ensure that your model looks realistic in various lighting conditions, which is essential for AR applications.

1. Use PBR-Compatible Materials:
   • Use the Arnold or Physical Material shader available in 3ds Max, as they are PBR-ready.
2. Material Setup:
   • Base Color (Albedo): Set up your base color texture map.
   • Metallic Map: Use this to define metallic areas (0 for non-metal, 1 for metal).
   • Roughness Map: Controls the surface roughness (0 for smooth and shiny, 1 for rough and matte).
   • Normal Map: Adds surface detail without increasing polygon count.
   • Occlusion Map: Adds depth to shadows.
3. Texture Resolution: Keep texture resolutions optimized for performance. Generally, 1024x1024 or 2048x2048 are sufficient for AR use.
4. Check UV Mapping:
   • Ensure your model’s UVs are unwrapped correctly with no overlapping, as this affects the material appearance.

Step 3: Setting Up for Export

Before exporting, ensure your model and scene are correctly set up:

1. Scale: Set the correct scale of your model. AR platforms typically use meters, so adjust your model to real-world dimensions using the “System Unit Setup” in 3ds Max.
2. Pivot Point: Place the pivot point at the base of the model for proper placement in AR environments.
3. Freeze Transformations: Freeze transforms to reset scale, rotation, and position values to default.

Step 4: Export Settings for GLB Format

Exporting to GLB ensures that the model, textures, and animations (if any) are packaged into a single file.