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Dynamic Tail

Dynamic Tail

In this tutorial you'll learn how to setup a tail with physics and how to steer the look and feel of the simulation using normal keyframing techniques. We'll use one of the excellent rigs by Truong CG Artist.

Out of date

This tutorial was written for 2021.03.01 and a few things have changed since then.

  • Dynamic Control menu item was renamed Active Chain
  • rGuideMultiplier shape node was renamed rGlobalStrength
  • Blend Simulation = 1.0 attribute was renamed Simulated = On/Off

Optional example files


Walkcycle

Let's start with a walkcycle, and move towards interacting with the environment.

Apply Simulation

Select the hip followed by each tail control along the tail in order, and click Create Dynamic Control.

01_Setup

Reduce Gravity

This particular rig is very small, about 1.6 cm tall, so we need to reduce the default Gravity to reflect this.

01_B_Gravity

Global Strength

The first selected Dynamic Control contains a Guide Multiplier to influence the strength on all of the tail controls at the same time.

02_Multiplier

Local Strength

You can also adjust the strength values individually for each joints, to taper their stiffness along the length of the tail.

03_Falloff

Strength Falloff

Let's taper the strength along the length of the tail.

tweaking_values

Result

Let's see how it looks.

wolf_animated


Sitting Down

Now let's see how to steer our simulation with regular keyframes.

Switch to Animation

The simulation will try to follow your keyframe animation. Just switch off the Simulated attribute on the root control while you're animating, then switch it back on to see how it looks.

animate

Animation vs Simulation

You can see the animation input on the left and the resulting simulation on the right. With just 3 keyframed poses we end up with this result. Note that I had to overcompensate my animation poses to fight gravity when the tail swings around.

anim_input


Advanced Control

Gain even more fine-grained control with these advanced topics.

Flex and Relax Muscles

By keyframing the root strength multiplier you can flex or relax the muscles in the tail. The higher the value the stiffer it gets and the lower the value the more relaxed it becomes, allowing gravity to drop it to the ground.

key_str_mult_3

Damping

Damping controls how fleshy and sluggish your simulation behaves.

04_Damping

Low or zero damping preserves more energy in the system, making a simulation more elastic or rubbery. Creatures and humans tend to look best with moderate to high damping values.


Last update: 2021-08-27