What do you usually do if you like a particular cartoon character? Buy a figurine of it?

That's what most people would do. Unfortunately, however, it is just for decoration. Therefore, I tried to create a way of sending these figurines back to the virtual world — In short, I created a virtual but moveable 3D model of a figurine.

This is done with auto rigging, a new capability of HMS Core 3D Modeling Kit. It can animate a biped humanoid model that can even interact with users.

Check out what I've created using the capability.

What a cutie.

The auto rigging capability is ideal for many types of apps when used together with other capabilities. Take those from HMS Core as an example:

Audio-visual editing capabilities from Audio Editor Kit and Video Editor Kit. We can use auto rigging to animate 3D models of popular stuffed toys that can be livened up with proper dances, voice-overs, and nursery rhymes, to create educational videos for kids. With the adorable models, such videos can play a better role in attracting kids and thus imbuing them with knowledge.

The motion creation capability. This capability, coming from 3D Engine, is loaded with features like real-time skeletal animation, facial expression animation, full body inverse kinematic (FBIK), blending of animation state machines, and more. These features help create smooth 3D animations. Combining models animated by auto rigging and the mentioned features, as well as numerous other 3D Engine features such as HD rendering, visual special effects, and intelligent navigation, is helpful for creating fully functioning games.

AR capabilities from AR Engine, including motion tracking, environment tracking, and human body and face tracking. They allow a model animated by auto rigging to appear in the camera display of a mobile device, so that users can interact with the model. These capabilities are ideal for a mobile game to implement model customization and interaction. This makes games more interactive and fun, which is illustrated perfectly in the image below.

As mentioned earlier, the auto rigging capability supports only the biped humanoid object. However, I think we can try to add two legs to an object (for example, a candlestick) for auto rigging to animate, to recreate the Be Our Guest scene from Beauty and the Beast.

How It Works

After a static model of a biped humanoid is input, auto rigging uses AI algorithms for limb rigging and automatically generates the skeleton and skin weights for the model, to finish the skeleton rigging process. Then, the capability changes the orientation and position of the model skeleton so that the model can perform a range of actions such as walking, jumping, and dancing.

Advantages

Delivering a wholly automated rigging process

Rigging can be done either manually or automatically. Most highly accurate rigging solutions that are available on the market require the input model to be in a standard position and seven or eight key skeletal points to be added manually.

Auto rigging from 3D Modeling Kit does not have any of these requirements, yet it is able to accurately rig a model.

Utilizing massive data for high-level algorithm accuracy and generalization

Accurate auto rigging depends on hundreds of thousands of 3D model rigging data records that are used to train the Huawei-developed algorithms behind the capability. Thanks to some fine-tuned data records, auto rigging delivers ideal algorithm accuracy and generalization. It can implement rigging for an object model that is created from photos taken from a standard mobile phone camera.

Input Model Specifications

The capability's official document lists the following suggestions for an input model that is to be used for auto rigging.

Source: a biped humanoid object (like a figurine or plush toy) that is not holding anything.

Appearance: The limbs and trunk of the object model are not separate, do not overlap, and do not feature any large accessories. The object model should stand on two legs, without its arms overlapping.

Posture: The object model should face forward along the z-axis and be upward along the y-axis. In other words, the model should stand upright, with its front facing forward. None of the model's joints should twist beyond 15 degrees, while there is no requirement on symmetry.

Mesh: The model meshes can be triangle or quadrilateral. The number of mesh vertices should not exceed 80,000. No large part of meshes is missing on the model.

Others: The limbs-to-trunk ratio of the object model complies with that of most toys. The limbs and trunk cannot be too thin or short, which means that the ratio of the arm width to the trunk width and the ratio of the leg width to the trunk width should be no less than 8% of the length of the object's longest edge.

Driven by AI, the auto rigging capability lowers the threshold of 3D modeling and animation creation, opening them up to amateur users.

While learning about this capability, I also came across three other fantastic capabilities of the 3D Modeling Kit. Wanna know what they are? Check them out here. Let me know in the comments section how your auto rigging has come along.