Simple Cloth Deformation Trick

Sometimes, it’s the simplest tricks that yield the best results. When it comes to rigging tubular arms, achieving a visually pleasing deformation can be a challenge. However, we applied a technique that made the process significantly easier.

In this approach, we employed a cloth simulation for every pose that we wanted to achieve. By doing so, we were able to attain the desired level of realism and flexibility. To achieve the final output, we extracted the cloth simulation as a corrective blendshape.

To ensure seamless transitions between poses, we developed a system to trigger the appropriate blendshapes based on the arm’s movement. This allowed for smooth and natural arm animations, even in complex movements.

By utilizing this simple technique, we were able to overcome the difficulties associated with rigging tubular arms and achieve a better deformation.

Here are a few methods to activate the blendshapes:

• Connecting the lowerArm joint rotateY axis to the blendshape weight attribute.
• Calculating a distance between 2 elements:
  • A locator child of lowerArm + a locator child of UpperArm. With a distanceBetween node, we use each locator worldPosition to feed the distanceBetween node. Then, based on the values when the arm is open vs closed, we use a setDrivenKey to feed the blendshape weight attribute.
• Using an angle interpolator. This setup is quite complex but works very well. I will detail the procedure in a separate blog post.

Stay tuned for more insightful tricks and techniques to enhance your 3D rigging skills!