Why a 3D standard?
A 3D model needs to meet a certain standard. If your model meets those standards, it's possible to use it for all kinds of different experiences, including augmented reality (AR) and virtual reality (VR), marketing, and product rendering. However, if your model does not meet the standard, you will experience problems and struggles. And in the worst case, your model needs to be reworked into a better format! This guide will explain these modeling standards.
Do you want to know more about 3D models? Check out all the other related articles in this Help section.
Best practices for creating 3D Models
3D model requirements for glTF and GLB
Size matters
Every 3D object used for creating your Experience needs to be downloaded by the end-user. Therefore Size Matters. Our recommendation is not to exceed 25 MB* per glTF model.
* Fectar platform was built with two specific reference devices: the iPhone 6S (2014) and the Samsung S7 (2015). If your audience has newer smartphones with better performance, you can go up to 100 Mb. But take into account that this will also take more time to download (depending on the connection speed) and potentially additional data cost for mobile users. You can in that case advise using the content offline in the Fectar app.
Polycount
A polygon is a face created by connecting three line segments into a closed-form, like a square, triangle, or hexagon. For example, in 3D models, you have a triangle when you break down the geometry into the smallest form of a polygon. Geometry that appears round or circular has a lot of smaller faces. The smaller the faces, the smoother the appearance yet, the higher the polycount.
The polycount of a model, or how many polygons/triangles a model has, is one of the best ways to measure the efficiency of a model. You can determine a model's efficiency by comparing its visual quality to its polycount. Typically, the higher the visual quality and the lower the polycount, the more efficient the model. Simply put, it is a balance between visual quality and poly/triangle count that makes an excellent low poly model.
Our recommendation is not to exceed 100.000 triangles per glTF model.
Textures
Textures give a 3D model a specific look. For example, textures provide the color, make the object metallic and make the 3D object reflective. Textures for AR and VR use physically-based rendering (PBR) workflow. Most of the time, they have four types of texture maps:
- diffuse
- normal
- roughness
- metalness
- occlusion
Sometimes, and lately, more often, you have a texture called ORM; this is a single map with occlusion, roughness, and metalness mapped to the red, green, and blue channels.
Our recommendation is to use the PBR workflow.
To Save the textures as a JPEG with a maximal resolution of 2048*2048