Run Cycles [Locomotion and Mechanics for Animation - Unit 06]

Run Cycle

24/10/24

Introduction

This blog post explores the exercise of animating a run cycle. This builds on the previous locomotion exercises of animating various walks and looks at how this differs for a run. This is another core exercise and will focus on a standard run opposed to stylisation. Therefore, core theory will be studied to establish a strong foundation that can be adapted for further stylisation and characterisation as needed. This blog post will explore theory analysis through to animation development.

Theory Analysis

Firstly core animation theory was studied in depth to build a solid knowledge base that can be implemented in the animation. Firstly, The Animator's Survival Kit (Williams, 2009) was studied and the findings are detailed below.

(Williams, 2009, pp.176 - 177)

The key findings from this section (Williams, 2009, pp.176 - 177) were :

• Core concept  that in a  walk there is always a foot on the ground whereas in a run there is a point where both feet have left the ground. 
• Normal run typically has 6 frames per step, 4 steps in a second.
• The cartoon run extends the period the character is in the air.

(Williams, 2009, pp.178 - 179)

The key findings from this section (Williams, 2009, pp.178 - 179) were :

• Realistic run has a reduced arm motion and less up and down in the body.
• We can stylise a run in many different ways to add personality, however, on the whole there are less frames to work with than a walk so you're slightly more restricted.
• Up and downs should be raised by only a half or third of a head.
• Runs are created on ones to help control the motion, this will be important when animating digitally to really control the in-betweens.
• We can curve the body to create a concave or convex shape on the passing poses
• We can twist the hips and counter twist the shoulders as we did with a walk.

(Williams, 2009, pp.180 - 181)

The key findings from this section (Williams, 2009, pp.180 - 181) were :

• Traditional cartoon run could be on 4s or 8s.
• Straight leg on contact to add more vitality and reach.
• Start with your contact poses as we did with the walk, however, you could start with any position.
• In a run we want less mirroring of poses - e.g. contact left foot should not mirror contact right foot. Otherwise we will see the loop a little too easily and it will feel more mechanical. Particularly important for fast runs e.g. 4 frame step.

(Williams, 2009, pp.182 - 183)

The key findings from this section (Williams, 2009, pp.182 - 183) were :

• You can lean the body forward more than a walk. The faster the run, the further you can lean the character.
• Doesn't have to be in balance all the time because the character will catch themselves.
• 6/8 frame runs are considered the most aesthetically pleasing.
• Arms can be varied as much as the legs.
• On faster runs if you swing too much it can be confusing!

(Williams, 2009, pp.184 - 185)

The key findings from this section (Williams, 2009, pp.184 - 185) were :

• Swinging arms from side to side can force perspective.
• Varying the down positions will add more variety and make it seem like it repeats less.
• You could bake the animation and make every other passing pose a down pose.
• You double make the arms pump twice as fast as the legs to make it more energetic. This would create some twinning but then random overlap.

(Williams, 2009, pp.186 - 187)

The key findings from this section (Williams, 2009, pp.186 - 187) were :

• Bend the body back to off balance the character but swing the arms forward for the balance, maybe slower!
• To vary positions you can change how the back arches, how the feet rotate and how the legs and arms animate.
• The slower the run, the shorter the stride.

(Williams, 2009, pp.188 - 189)

The key findings from this section (Williams, 2009, pp.188 - 189) were :

• A fat character will have more up and down due to the weight. Down comes right after up and then there is a slow up due to the weight.
• When going around a corner you will lean into the corner.
• Fast runs are suited more to smaller characters with longer legged characters needing more time to complete their cycle.
• On a fast cycle its hard to get good arm motion so stretching the arms forward as if chasing can help.
• Very little up and down on the fast runs.

(Williams, 2009, pp.190 - 191)

The key findings from this section (Williams, 2009, pp.190 - 191) were :

• Demonstrates some variations on run cycles.

(Williams, 2009, pp.192 - 193)

The key findings from this section (Williams, 2009, pp.192 - 193) were :

• Reinforces that short cycles are easy to see the loop but adding variations delays the eye seeing these patterns.
• Highlights that we need at least 3 frames for a step or the eye won't be able to see the loop of the feet due to the repetition.
• Short cycles work best with cartoony characters.

(Williams, 2009, pp.194 - 195)

The key findings from this section (Williams, 2009, pp.194 - 195) were :

• Can go a little faster if you do 3 poses for the first step and reduce to 2 for the second.

(Williams, 2009, pp.196 - 197)

The key findings from this section (Williams, 2009, pp.196 - 197) were :

• This explores the challenges of a 2 frame run and how this can be tackled! This reinforces the need for variation in poses so that it reads more complex and less like a mechanical or mirrored action.

(Williams, 2009, pp.198 - 199)

The key findings from this section (Williams, 2009, pp.198 - 199) were :

• Highlights further variations for 2 frame run including the use of blurs to smear the action.

(Williams, 2009, pp. 200)

The key findings from this section (Williams, 2009, p. 200) were :

• This highlights some key findings to sum up this chapter and will serve as a checklist for me when reviewing the quality of my run cycle.

Lastly, some good thumbnails from the Cartoon Animation with Preston Blair (Blair, 2020, p.75) are included to further study the key poses across a run from an alternative source. 

(Blair, 2020, p.75)

Animation

This section shows the practical animation development of a 6 frame run cycle.

Perspective :

Turn Around :

Conclusion

The outcome of this exercise was good and achieves the goal of creating a neutral run that implements core animation theory of this locomotion exercise. This run is fairly quick! As you can see in the leg motion. There is some variation in the key poses, however, probably not quite enough because the leg motion doesn't read quite as well at this speed. Further variation in the poses on each leg would allow the eye to read the animation a little stronger. The arms work really well in this animation because it creates a good pumping motion. The body remains a little stiff, however, this works well to contrast the large motions in the legs. The cycle loops well and implements core theory well. It would be interesting to create a slower run perhaps with a heavier character rig to compare and implement the core theory with further characterisation.

The learning outcomes, listed below, have been achieved because :

1. The mechanics of a run have been studied through analysing theory lectures from the module and analysing animation theory books.
2. A basic run cycle has been animated as shown in the playblast videos and reflect upon in the conclusion.
3. The graph editor amongst other tools within Maya have been used as needed to achieve this outcome.
4. This run cycle has not yet been adapted, however, reflection of how this could be adapted in the future, similar to how walks were adapted in a previous blog post, has been explained.
5. A dynamic animation sequence has been created with lots of energy and good key poses. Areas for development have been noted in the conclusion.

Learning Outcomes 

1. Understand the mechanics of running
2. Animate a basic run cycle
3. Use advanced Maya techniques
4. Adapt run cycles for different characters
5. Create dynamic animation scenes

Reference List

1. Blair, P. (2020) Cartoon Animation with Preston Blair. Mission Viejo, CA: Walter Foster Publishing.
2. Williams, R. (2009) The animator’s survival kit. London: Faber and Faber.