Preparing a 3D model in Blender for use in Augmented Reality, as shown on the right part of the image.

15 tips for preparing 3D For AR

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by

Kristopher Blom
in

3D models are the foundation of Augmented Reality, but not all 3D content is designed for use in AR. Whether preparing 3D models directly or porting existing 3D content for use in AR, here are 15 tips for preparing 3D for AR.

After you have prepared your 3D for AR, deploying it to AR can be as easy as 5 steps.

Scale and Units

  1. Real-World Scale. Ensure the object is modeled to real-world dimensions. This is critical for accurate placement and interaction in AR. Most systems assume Meters, but most good systems can apply import scaling to correct the scale. Sometimes the scaling will affect the animations to where possible covert your source.
  2. Units. If you are creating a scene from multiple 3D models, consistently use the same unit of measurement (e.g., meters or centimeters) across all assets. This makes it much easier to compose scenes and avoid scale issues. If, for any reason, this consistency cannot be maintained, it can be corrected in most AR system.

Mesh and Structure

Before preparing a 3D model for use in Augmented Reality, it’s crucial to ensure it is optimized for performance and compatibility. AR relies on real-time rendering and on mobile devices, which demands lightweight models that maintain a balance between visual fidelity and computational efficiency.

  1. Polygon Count. Keep the polygon count as low as possible while maintaining the quality of the object. Devices capable of AR vary in capabilities; therefore, the maximum polygon limit may vary fairly greatly if you want to support every device possible. We strongly recommend clients not exceeding 3 million polygons for an entire scene, regardless of device performance. The goal should be to aim for under 700,000 polygons simultaneously rendered in a scene.
  2. Pivot/Mesh center. Plan the placement of pivots carefully, especially for objects that will be animated. Sometimes, it’s advantageous to place pivots at the geometric center of an object (e.g., for round shapes) or align them along one of the edges (for other shapes). In certain cases, placing the pivot at the edge of the object or another specific location may result in more efficient animations.
  3. Model Structure. A proper hierarchy of objects saves time when animating and editing. It is essential to group objects intended for joint animation under a single node and use hierarchies if the behavior needs to be compound.

Texture and Materials

  1. Texture Size. Similar to reducing the polygon count, minimizing texture size directly increases the number of devices that can support your AR presentation or guide. Use textures no larger than necessary (e.g., 512×512 or 1024×1024 for mobile). Optimize images to reduce file size without compromising quality. Note that the mobile platforms do not support textures larger than 4096×4096 and older devices no larger than 2048×2048.
  2. File Formats. Save textures in formats like .JPEG or .PNG.
  3. Material Count. Minimize the number of materials to reduce rendering complexity. Avoid duplicating materials unnecessarily and avoid unique materials for no reason (common in CAD systems).
  4. Shaders. Do not focus on shaders if you are using a AR platform instead of coding your own App using a gaming platform like Unity. Most platforms will have some preset materials instead of adjustable shaders.

Lighting

  1. Light sources. Light sources are hard to make work in AR in the best of cases and no-code/low-code AR platforms will have at most limited support. To pull it off you need to either be matching the real world light sources (possible in some AR platforms like Misterine AR platform automagically) or have a complex setup that attempts to relight the real world. These are advanced features that only make sense for custom development in specific circumstances.
  2. Baking lighting. Avoid baking lighting into textures unless necessary for a specific aesthetic. Augmented Reality integrates your model into the real-world, so the lighting will not match unless you control the location and lighting in real world also.
  3. Develop using neutral lighting. Use neutral lighting for previews while modeling to ensure adaptability to various environments.

Animation

  1. Simplicity of animations. Keep animations simple and lightweight.
  2. Using only supported animations. Most AR platforms supports only a limited set of animations. Keyframed animations are generally the baseline of support, though many systems also only support special animation generators. See ways to get animations in Misterine AR.

    Types of animations you may need to avoid:
    • Skeletal Animations. Skeletal (bone) animations are not universally supported by AR platforms. Baking the animations before export can sometimes be used to solve this issue.
    • Mesh Animations. Mesh animations, including Shape Key animations, are often associated with skeletal animations, but may also be separate. Support for mesh animations is limited. There is also no way to bake such animations.
    • Material and Texture Animations. Material and texture animations are not generally supported in AR since the viewpoint of the user is always unknown and moving. Some simple properties, such as Base Color and Transparency, can be recreated in some of the systems.
    • Lighting Animations. Lighting generally isn’t a good idea in AR and moving lights are just an extension of that. That the lights don’t affect the real world will just be more obvious through the lack of light play during movement.

File Formats

  1. Find format that works. For most AR platforms you won’t be importing native format files. Instead, you will need to export into an exchange format. Finding the right format is critical and often requires some experimentation. Which is the best depends on the exporter, the importer, and even your content.

Common formats that tend to work best:

  • ‘.FBX’ – Autodesk FBX is the most common 3D exchange format and likely the most universally supported. FBX exporters are not always well implemented and adjusting parameters may be required.
  • ‘.OBJ’ – Wavefront OBJ is an old format, but broadly supported for what AR usually supports.
  • ‘.GLTF’ and ‘.GLB’ – GL Transmission Format
  • ‘.STL’ – Stereolithography is widely used for 3D printing. Like OBJ it’s simplicity makes it generally work for what it supports.
  • ‘.STP’, and ‘.STEP’ – Standard for the Exchange of Product Data (ISO 10303, widely used for CAD data exchange and interoperability)
  • ‘.3DS’ – Autodesk 3D Studio (an older format for 3D Studio Max)
  • ‘.PLY’ – Polygon File Format (Stanford, often used in 3D scanning)
  • ‘.DXF’ – Autodesk Drawing Exchange Format (used for CAD)