The Smart Way to Auto Rig Soft, Rigid, & Mixed Armor Pieces

José Antonio Tijerín

José Tijerín is a digital illustrator, 3D sculptor, and creator of video games such as “Dear Althea” and ” The Evil Furry” available on Steam. His content pack “We’re Besties” and “We’re Homies” are currently for sale in the Reallusion content store.
Type II: Mixed structure
In this tutorial, I’ll explore what I call a mixed structure for making a suit of armor with Reallusion‘s toolset. This type of structure is very suitable for making robots and cyborgs because it has a more modern or even futuristic aesthetic. We’ll be using the “Neo Robot” character which comes with this exact system of mixing rigid and flexible structures. You can download this character from Sketchfab.

How to use AcuRIG in Character Creator 4.1
First, import the character directly into an empty project in Character Creator. If you haven’t done so already, proceed to rename all the parts of the robot to make it easier to work with later. After that, we can ready to use a new tool that Reallusion has added into Character Creator.
AccuRIG is a tool that has opened new horizons for Reallusion products. Now, Character Creator is no longer a program entirely focused on realistic or stylized characters, it can actually load all types of characters. With this improvement, Character Creator is no longer limited to certain types of projects and has become an essential tool for any project that involves 3D models.

I’m going to select some of the rigid components and click on the AccuRIG button on the right. In the AccuRIG menu click on the Create Guides button. The system will proceed to place the joints in an arrangement that it deems best based on its algorithm.

Can we confirm if these are the best positions for the joints and modify it to better fit our model. Character Creator makes this easy by displaying a small help window every time a joint is selected. The system is usually pretty good at placing the joints into correct positions.

When we have verified the joint positions, click on the Generate Skeleton button. This is where the magic happens. In other programs, creating and adjusting a skeleton would undoubtedly take hours of your time.

The skeleton that the Character Creator generates is perfectly adjusted to fit the character’s anatomy. Yet, we can still adjust some parts that we are not satisfied with and use the Bind Skin button. As you can see in this example, the results are fantastic. It is even perfect for the fingers which are usually prone to errors due to their close proximity with one another.

Even the rigid parts of the model deform so slightly that it is almost imperceptible. That’s why for cases like these, it’s better to leave the rigid pieces as parts of the model rather than separating them into individual pieces.

Models with a lot of overlapping parts will likely encounter mesh penetration, but you can use the Skin Weights tool to quickly check the skinning. Another thing you have to take into account is that you can’t use the Transfer Skin Weights button to fix mistakes in your rigged characters, instead you will need to go back to the AccuRIG menu and use the Bind Skin button.

Animated add-ons in iClone 8
When dealing with robots in iClone, there is one factor that you should take into account, that is animated components. Electronic components are often tacked onto futuristic characters and they may even have their own motions.
Adding these elements is really easy in iClone. We simply need to import the pre-rigged components and position them in the right places. When they are all positioned, we have to use the Link option on the nearest bone of our character and we can animate this element independently without separating it from the body.
Furthermore, we can explore the use of robotic extensions as part of the character’s body.

The classic example is the articulated arm that is fully animated. Creating this setup is much easier than you might think, thanks to AccuRIG. We can simply import the mechanical arms into Character Creator and press the AccuRIG button to start the rigging process, just like before.
In this case, not all bones will be needed for this model, such as the leg bones. AccuRIG provides a practical solution to mask out these bones so that they don’t interfere with the rigging process. As mentioned a moment ago, we can just import the model into iClone and use the Link option to attach it to our character.

Type III: The rigid system
The rigid system is one traditionally used for classic robots. It is the most complicated system because we cannot use elastic elements and deformations, forcing us to think very carefully about the structure that makes up the character.
Use of spheres in the joints
As you can see, the whole system is based on using spheres as joints, but we also have some hydraulic parts that will need to be integrated into the rig.

Now check how well the sphere system works in Character Creator and let’s see just how useful it can be to incorporate the hydraulic tubes. These tubes have polygons at the top and bottom. In this way, the lower polygons can bind to the hips and the upper polygons can bind to the chest. When the character moves it gives the impression of the hydraulic tubes sliding to smoothly expand and contract. This method was used in practical production for my upcoming video game “The Evil Furry” on Steam.
In this version, I wanted the robot to be more friendly, so I added light bulbs on the sides of the spheres that can move independently. I also added two antennae with spring effects to make the head more dynamic.
Facial expressions on a deadpan robot
I also wanted this robot to possess facial expressions and the ability to talk, despite it being a rigid robot. It occurred to me that the way to do this is to use a base character in Character Creator with all the expressions and lip-sync systems already set up with what the program has to offer.

To have all these features, I needed to work off of the base character and add the rest of the armor as clothes. It is a slower process, but it’s worth it for all the animations and expressions that the face has to offer.
That is all! I hope you like the final result and that the tutorial has helped you.

Read on ‘How to Auto Rig Cyborgs with Character Creator AccuRIG – Part 1‘
Learn more :
• Tijerín Art Studio (José Antonio Tijerín) https://sketchfab.com/tijerin_art
• Tijerín Art Studio on Steam (video games) https://store.steampowered.com/app/2058230/The_Evil_Furry/
• Character Creator https://www.reallusion.com/character-creator/download.html
• iClone https://www.reallusion.com/iclone/download.html
• Reallusion https://www.reallusion.com/