3D Models for Overlays


Quick Overview

To upload a 3D model, Aurasma Studio requires a file to be in a .tar format, which can be created with a number of computer programs. We recommend 7-Zip for Windows and GUI Tar for Mac.

A .tar file should contain:
•The exported/scene model using OpenCollada (.dae file)
•All textures referenced in the scene file (.png format)
•.png thumbnail (256×256 pixels), named thumbnail.png
•.mp3, if sound is required

What formats do you support?

Our 3D model support is based on the Collada format (v1.4 or v1.5), as exported by Maya 2012 and 3DS Max 2012 (OpenCollada Exporter).

Uploading to the Aurasma Studio

Open the  Overlays screen, click  Add, and select your .tar file (don't click on Bulk Add).

Due to the processing limitations of today's devices the first generation of 3D models should meet the following criteria:

Models
•Under 10,000 triangles.
•Scene should be centred around the world origin (0, 0, 0) to ease placement.
•Meshes must not have any non-uniform scaling.
•Exported meshes must be triangulated. (This is usually handled automatically at export stage if the option is selected.)
•No more than 20 objects (meshes) in a scene. Animated rigid geometry is less processor-intensive than skinned geometry, but extra draw cells are more intensive. (Ultimately, once you have passed 10 or so objects, it is something that needs to be looked at on an individual basis.)

NOTE: Consider what you're making and how much screen space it will take up - you won't need 10,000 triangles and a 1024 square texture for an object that may only be 3cm tall on an iPad screen.

Textures/Shaders
•One material per mesh. If you need two materials then use multiple meshes.
•Individual texture maps (.png format) must be of a dimension to the power of 2 (we recommend 128×128, 256×256, 512×512 or 1024×1024). Textures cannot be larger than 1024×1024 pixels.
•Limit your maps to no more than 2 per scene. For optimised loading times, reduce the number of maps. The use of smaller, tiled textures is fully supported and recommended where appropriate.
•Emissive, normal and diffuse maps are supported, as well as specular colour (but only when using the OpenCollada exporter).
•Use the simplest shader possible for each situation. The order of complexity is as follows: constant < lambert < phong < blinn.
•Alpha blending is very processor intensive. If you use alpha on sections of mesh, put it in its own shader. Alpha on solid objects is not recommended and is better suited to planes.
•Material names must not contain spaces, brackets etc.
•Material names must not start with a number (OpenCollada characteristic).

Rig
•Bone names must not contain spaces, brackets or other special characters — replace spaces with underscores if needed.
•The export rig should contain a maximum of 100 bones to optimise playback — the performance hit comes largely from skinning.
•It is advisable to name all bones properly.
•Objects cannot be linked/parented to non-export objects — constrains are fine.
•Do not scale anything.

Animation
•All animated objects/controllers must have a key on the first and last frames.
•When exporting a .dae, you must bake and resample keys in the Collada options (see above).
•No animated materials/material parameters.
•Scaling is correctly supported in animation.
•No animated light colour.

Lights
•Scenes must be lit. 3 lights are recommended. Breaching this will cause performance slowdown on less powerful devices.
•Omni/point/directional lights are supported — we recommend point/omni lights.
•Light value is based on the light's colour value, not intensity, e.g. mid grey = 0.5 multipler.
•Ambient light is supported, but may cause overexposure to scene.

With the constant technological development of smartphones, yet more complex 3D models will be supported by Aurasma.

Sample models
•AurasmaBox — contains simple textured model with animation and four point lights (1.3 MB)