Refer to FOL for assignment weight and due date.
Trot Cycle Animation. (TC) Animate the Rhett Horse rig (download the rig HERE) in a Trot Cycle, using a layered animation workflow. After the initial trot cycle loops smoothly, students will extend the assignment in one of three ways; by adding a rider, changing gait or adding non-looping behavioural element . cycle (19-22fr) final assignment length varies. Naming for hand in should be: <Last>_<First>_TC.ma / "".mp4.
Alternative rigs:
Gorgeous George by Dmitri Kolpakov
Horse by Carlos Contreras
Vondin Horse by Joel 3d (not https://)
What I'll be grading on this assignment:
- Does your animation cycle smoothly with no-pops or hitches evident?
- Is there photo-realistic subtlety and complexity?
- Have you made good use of reference to create an authentic performance?
- Can the cycle move forward, with the feet locking to the ground?
- Have you successfully extended the assignment
Here's an beautiful example of the finished assignment, animated by Evgeniya Ratner:
Bravo Evgeniya!
We're doing a trot cycle specifically for a few reasons:
- It's a short cycle, typically 18-20 frames or so.
- The mechanics are bigger than a walk and they are usually symmetrical.
- The tutorial walks you through each step of the way: this assignment is as much about learning a layered animation approach as anything else.
- There's plenty of trot reference.
Three important tips before we start:
1) REFERENCE IS CRITICAL. When creating photo-realistic animation, don't try to improvise or make it up as you go. Don't animate how you think an animal moves; FIND EXAMPLES and refer to them constantly. The motto for this class is:
Find Reference, Analyze it Carefully and Refer to it Often.
Now that you know that rule...2) SOMETIMES WE DON'T FOLLOW THE REFERENCE. Confusing, right? Though reference is critical for realistic animation it doesn't mean we slavishly copy the reference; in some cases we depart from reality to meet audience expectation, to match director feedback or improve visual readability. Reference is an important starting point and a helpful road-map to success but it is not the only factor to creating good animation. Careful analysis will help us determine when to follow reference and when to change it up a bit.
3) WE'RE GOING TO USE A LAYERED ANIMATION WORKFLOW. These next few weeks are designed to help the student create a workflow for animating a cycle. We will be using a Layered Animation workflow rather than the typical Pose-to-Pose workflow we're accustomed to. Here is an explanation of the two different methods of animating:
Layered Animation: With this workflow, the animator creates movement on one controller at a time, one channel at a time. Curves will be copied, offset and sometimes inverted. Work starts with animation controllers that have the largest effect on character movement (Root, Torso, etc) and ends with controls that affect only small parts of the character (Ears, Tail, etc.)
Pose to Pose: This is the classical animation workflow. The animator creates key, 'storytelling', poses for an action and then manages the transition between those keys with breakdowns and inbetweens.
For best success, Please follow the Layered animation workflow shown in class. All set?
Week-by-week breakdown
Week 1: Part 1, Analyze reference. Build core mechanics in the body. Basic foot animation
Week 2: Part 1, Twisting & rolling in the hips/shoulders. Head/neck animation. Refining the feet
Week 3: Part 2, Testing the cycle moving forward. Extend the assignment
Week 4: Part 2, Final polish on cycle and additional animation (gait change, added rider, or extended cycle)
PART 1 of this assignment (week 1-2) starts with a basic cycle of a trotting quadruped. You will use the Rhett Horse rig. Careful reference and a layered approach to creating the animation is needed here.
PART 2 of the assignment (week 3-4) requires you extend the animation in one of the following ways:
- add a gait change to a faster or slower speed (run or walk)
- add a mounted rider on the back of your creature
- extend the cycle with non-looping embellishments/variation
Week 1: Analyze Reference, Build Core Mechanics
It's called "trot_18_frames.mov". You can get it from:
\\180net1\ANM\assets\Rigs\Creatures_and_Animals\Horse_Rhett\reference_videos\..
original source; 'Riding Technique: The Basics of Posting' by Tiffany Winkel
TIP: Whenever I'm animating a cycle, I always start on frame 0. Why? Because it makes the math much easier to work out. (and I hate math) If your cycle runs from x0-x18, you know that the halfway point is x9. This little trick helps me stay organized and makes sure that both halves of my cycle are even. If you don't keep the two halves equal, your cycle may feel like it's limping or hitching.
To Start:
- Launch maya.
- Create your maya project file.
- File->Set Project->Set your maya project file
- Copy the file: Rhett_v1_4_3_new_UV.ma from \\180net1\ANM\assets\Rigs\Creatures_and_Animals\Horse_Rhett\.. to the assets folder of your maya project.
- Copy the reference video to the movies folder of your project.
- In Maya, create a new scene called <Last>_<First>_TC_wk1.ma
- Reference in the Rhett rig. (File> Create Reference) I always use a namespace of "A"
- In Maya (Create>Free Image Plane>☐). In the options, set width: 8.9, height: 6.68 (same ratio as the movie file.) Click "Apply and close."
- Select your new image plane and in the attribute editor and set it to look like this:
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| Be sure to match all the settings shown here, or the rest of the instructions may not make sense. |
The reference movie has a bit of movement in the framing, we can animate the image plane to stabilize our reference. This will make it easier for us to accurately match the range of motion.
I use the fence line and the ground plane as a point of reference for Ty, and the saddle for Tz. When those points are steady, I know I've stabilized my reference.
Now we're ready to start animating. We'll begin with just the TranY of the cog_CTRL (the blue arrow is pointing at it.)
I use the fence line and the ground plane as a point of reference for Ty, and the saddle for Tz. When those points are steady, I know I've stabilized my reference.
Core Mechanics: Torso Up/Down
Now we're ready to start animating. We'll begin with just the TranY of the cog_CTRL (the blue arrow is pointing at it.)
This is what the curve will look like. This gives us a quick springy bounce, with a long hang at the top of the arc. Perfect to create that feeling the horse has in the body when trotting.
TIP: We start with the most important elements and work our way down to the more minor bits. This first TranY curve is a really important part and has a big effect on the feeling of this animation. If you don't get this part right, later on your trot will feel more like the horse is stomping Make sure you match this shape exactly.
Here's a playblast of what we get from that:
Now we take that TranY curve, remove it from the cog_CTRL and copy it to the hips, middle and chest controls.
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| This is where we depart from the reference and change the movement to look more pleasing than reality. |
TIP: With animation cycles, it's really important to make sure the tangent angle of the key at the start and end of a curve is the same - otherwise there will be a pop at the start/end of the cycle. One way to make this evident is to briefly turn on pre/post infinity = cycle and then toggle on 'show infinity' in the graph editor. I don't use infinity cycle for a few reasons, so I'd immediately turn it off after you've checked everything.
With the above tip in mind, I'll make sure that the tangent angle of the key at the start of the curve matches the tangent angle of the key at the end of the curve. This will ensure everything cycles smoothly and seamlessly. Look at the start and end of the curve for the middle control as an example:
This is what I have now on the body. Even though the reference shows that the torso of the horse is a pretty rigid looking mass, this exaggerated ripple looks much more organic and pleasing. Here's the result of this offset.
We'll start with the back feet first (once the animation is worked out, we copy it to the front feet.)
Because we're doing a cycle, we animate one foot first, then copy the animation over to the other foot. (with a few small adjustments.)
To make things a bit easier, I'm going to create some primitive cones as visual guides ( one cone for each foot.) I'll animate the cones based on my reference to get the maximum range of motion and approximate timing correct.
We'll return to the torso and add the rotations for twisting and rippling later. For now, we'll move on to animating the feet.
Core Mechanics: The Feet
TIP: With this layered animation workflow, don't get too worried about how things look at the start. Until we get all the parts working some bits will look odd. In this next segment, you'll be moving the feet, but the shape of the legs won't look right at first. Don't worry: as we add other bits of animation things will start to come together.
Because we're doing a cycle, we animate one foot first, then copy the animation over to the other foot. (with a few small adjustments.)
To make things a bit easier, I'm going to create some primitive cones as visual guides ( one cone for each foot.) I'll animate the cones based on my reference to get the maximum range of motion and approximate timing correct.
Here's another important difference where I'll depart from the reference video.
On the TranZ I'll make sure that the cones move at a steady rate (linear) for the moments when the foot is in contact with the ground and that they ease in/out when the foot is in the air. I'll copy the animation to the other cone twice, offset it by -9 frames (one half of the cycle) and then trim off the excess so that it runs from x0-18 again. Here's what I end up with.
On the TranZ I'll make sure that the cones move at a steady rate (linear) for the moments when the foot is in contact with the ground and that they ease in/out when the foot is in the air. I'll copy the animation to the other cone twice, offset it by -9 frames (one half of the cycle) and then trim off the excess so that it runs from x0-18 again. Here's what I end up with.
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| the highlighted section is when the foot is on the ground. This linear curve will be important later on. |
I'll make a copy of the animated cones and use them for the front feet. Both sets need to travel at the same speed when on the ground. Now that I have my guides, I'll animate the back feet so that the tips of the hooves line up with the point on the cone. I have TranY and TranZ along with RotX and Compress Fetlock. I'll use the 'region guide' texture map to make it easier to see my horse legs.
You may notice the leg shape will look a bit odd right now. When we start to add RotY and RotZ to the hips, the shape of the legs will improve. The important thing is that I'm matching the range of motion forward,back, up and down that I'm seeing in my reference video.
When I happy with the back feet, I copy that animation to the front feet. Be sure to copy to the foot on the opposite side of the body. The back left foot animation gets copied to the front right foot. Back right foot animation goes to the front left.
see picture:
Once I've copied it over to the front feet, I make some adjustments to the animation curves. Here's what I end up with on the TranY and TranZ:
Here's what I have so far:
FUN ANATOMY INFO: Here's a picture of how the structure of the hoof and fetlock function. The foot controller has an attribute called 'Compress Fetlock' that allows you to create the compression and extension in this area. A positive value gives you compression, a negative value is used for extension.
TIP: The springiness in the steps is from the ligaments in the foot of the horse. Check the arcs and spacing of the joints on the foot and leg of the horse as the legs fold and stretch. You can track the arcs using a draw tool on the computer, or with motion trails.
Where we are so far...
The up and down of the body should be done. You should have rough movement of the legs under the body using the feet controllers.
-----------------------------For next class you should be done up to this point-----------------------------
For the next part of this assignment, we're going to add the rotation in the chest and hips. There will be RotZ (Roll) and RotY (Yaw) and just a small RotX (Pitch) adjustment in the chest only.
Start with the RotY (Yaw) curve on the hips, and then copy and invert (*=-1) the curve onto the Chest. Offset the Chest curve so that it's 1 frame later. The extreme point of the RotY is when the legs are at their stride pose. (in this case, frame 5/6) It looks like this from above:
You may notice the leg shape will look a bit odd right now. When we start to add RotY and RotZ to the hips, the shape of the legs will improve. The important thing is that I'm matching the range of motion forward,back, up and down that I'm seeing in my reference video.
When I happy with the back feet, I copy that animation to the front feet. Be sure to copy to the foot on the opposite side of the body. The back left foot animation gets copied to the front right foot. Back right foot animation goes to the front left.
BL ---> FR
BR ---> FL
see picture:
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| This is why the region guide texture map is handy - it keeps you from getting confused about which foot is which. |
Once I've copied it over to the front feet, I make some adjustments to the animation curves. Here's what I end up with on the TranY and TranZ:
and here's the RotX and Compress Fetlock .:
FUN ANATOMY INFO: Here's a picture of how the structure of the hoof and fetlock function. The foot controller has an attribute called 'Compress Fetlock' that allows you to create the compression and extension in this area. A positive value gives you compression, a negative value is used for extension.
TIP: The springiness in the steps is from the ligaments in the foot of the horse. Check the arcs and spacing of the joints on the foot and leg of the horse as the legs fold and stretch. You can track the arcs using a draw tool on the computer, or with motion trails.
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| This illustration is from the Preston Blair book, showing how the legs fold up and stretch out with the body when leaping. |
Where we are so far...
The up and down of the body should be done. You should have rough movement of the legs under the body using the feet controllers.
Week2: Twisting and Rolling
For the next part of this assignment, we're going to add the rotation in the chest and hips. There will be RotZ (Roll) and RotY (Yaw) and just a small RotX (Pitch) adjustment in the chest only.
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| It's useful to know the terminology to describe rotational movement independent of a particular axis. |
Hips and Shoulders
Here's what the curves look like:
TIP: When adding roll to the hips, (RotZ) the tilt and twist happens when the feet contact and push off the ground, and not in mid-air. I create the roll on the hips first, and then when I like the look of it, I copy the curve to the chest, invert it and offset it by 1 frame. I make a small adjustment to keep the chest a little tighter on the extreme of the roll (the curve is sort of flat there.)
TIP: When adding roll to the hips, (RotZ) the tilt and twist happens when the feet contact and push off the ground, and not in mid-air. I create the roll on the hips first, and then when I like the look of it, I copy the curve to the chest, invert it and offset it by 1 frame. I make a small adjustment to keep the chest a little tighter on the extreme of the roll (the curve is sort of flat there.)
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| Just like the RotY, the RotZ of the chest is offset by 1 frame later. |
The finishing touch on the body rotations is that I add a small pitch forward (RotX) to the chest. That gets rid of the hunch in the back of the neck and will also help us with the reach for the front legs. About 2.5 degrees will do. We don't animate this - just keep it at a fixed value for the whole range.
I won't show you a picture because a flat curve is just no fun to look at. If you really want, you can imagine it would look something like this: ----------------------------------.
Boring, right?
You can see all of the layers of animation are starting to look closer to a finished result. Here is what we have so far:
Create a nice pose for the head and neck. A small translation on the head can help match the proportions of the rig to the horse in the reference video.
Copy the RotY and RotZ of the chest and paste it onto the neck controllers. Invert the pasted curves (*= -1) and scale them down by 50% (*= .5). We'll edit the animation later, but this will stabilize the head so it counter animates to the action in the chest.
Now let's get the front and back feet sorted out. We want those front legs nice and straight through the stride when the hoof is in contact with the ground.
We'll add some TranY to the shoulders to help the shape of the front legs. I've marked the right shoulder control (yellow curve) the Blue mark is the front of the stride where the hoof makes contact, the Red mark is the back of the stride, just before the hoof leaves the ground.
I won't show you a picture because a flat curve is just no fun to look at. If you really want, you can imagine it would look something like this: ----------------------------------.
Boring, right?
You can see all of the layers of animation are starting to look closer to a finished result. Here is what we have so far:
Head and Neck
Create a nice pose for the head and neck. A small translation on the head can help match the proportions of the rig to the horse in the reference video.
Copy the RotY and RotZ of the chest and paste it onto the neck controllers. Invert the pasted curves (*= -1) and scale them down by 50% (*= .5). We'll edit the animation later, but this will stabilize the head so it counter animates to the action in the chest.
Now let's get the front and back feet sorted out. We want those front legs nice and straight through the stride when the hoof is in contact with the ground.
We'll add some TranY to the shoulders to help the shape of the front legs. I've marked the right shoulder control (yellow curve) the Blue mark is the front of the stride where the hoof makes contact, the Red mark is the back of the stride, just before the hoof leaves the ground.
Let's use some TranZ on the elbow controls (the ring controls where the front leg attaches to the body) to help the reach of the legs. The light blue curve is the Right elbow.
Now we just need to sort out the back legs with some small TranY adjustments. Again, I've marked the right back hip (yellow curve) the Blue mark is the front of the stride where the hoof makes contact, the Red mark is the back of the stride, just before the hoof leaves the ground.
Let's have a look at what we have now.
The front legs should be nice and locked straight through the contact stride, the back legs should have a lively spring to them and the shoulders should look flexible without changing volume.
Pretty exciting; we're almost there! All that's left is to animate the head (that counter-animation we did earlier isn't quite the right thing for a realistic horse) and add a little overlapping action in the tail.
For the animation of the neck the first control (lowNeck) has RotX,Y, and Z, the second control (midNeck) only has RotX .Here's what that looks like:
-----------------------------------end update---------------------------------------
Lecture: Offsetting the Animation and Moving the Cycle forwards
Today we will be adding offset and overlap to the horse animation, and moving it forwards along a ground plane. We will be adding a mane and tail. We will also be discussing our ideas for the next assignment.
Options for the Extended Assignment
Using the method demonstrated in class, move the horse forwards along a ground plane.
Dailies, work in progress - The Mighty Herd
WEEK 3 HOMEWORK:
Look at your reference for the horse trot again to add the final details:
Add a Rider: Constrain a humanoid character to the back of your trotting creature and animate them moving appropriately - they will need to cycle smoothly with the timing of your trot animation. Find video of folks riding horseback. How do they balance themselves and compensate for the movement of the animal? Make sure the movement of the rider matches the photo-realistic aesthetic of the mount.
Extend the Cycle with Non-Looping Behaviour: Take your cycle and duplicate it so it loops 10 times. Modify the animation to add actions that break out of the cycle and add personality to the creature. Some examples are:
Week 4: Polishing the Animation
Based on class feedback, refine your cycle animation and the extended elements. Continue to refer to your reference as you work. Follow good workflow practices for polishing. If you really want to polish your final work, a great tutorial for corrective blendshapes can be found HERE.
The front legs should be nice and locked straight through the contact stride, the back legs should have a lively spring to them and the shoulders should look flexible without changing volume.
Pretty exciting; we're almost there! All that's left is to animate the head (that counter-animation we did earlier isn't quite the right thing for a realistic horse) and add a little overlapping action in the tail.
For the animation of the neck the first control (lowNeck) has RotX,Y, and Z, the second control (midNeck) only has RotX .Here's what that looks like:
and now a little RotX to on the head to finish the whole thing off:
--------------------video of tail closeup--------------------------
-------------------horse video ref of ears.---------------------------
resist the temptation to animate overlap in the ears. The horse ears are not floppy and loose like a basset hound: they're active and stiff.
----video of final animation
-----------------------------For next class you should be done up to this point-----------------------------
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| Pay attention to the value chart on the left side of the graph - though this curve looks big, it's only rotating about 3 degrees. |
--------------------video of tail closeup--------------------------
-------------------horse video ref of ears.---------------------------
resist the temptation to animate overlap in the ears. The horse ears are not floppy and loose like a basset hound: they're active and stiff.
----video of final animation
-----------------------------For next class you should be done up to this point-----------------------------
Week 3: Test Cycle and Extend the Assignment
Lecture: Offsetting the Animation and Moving the Cycle forwards
Today we will be adding offset and overlap to the horse animation, and moving it forwards along a ground plane. We will be adding a mane and tail. We will also be discussing our ideas for the next assignment.
Options for the Extended Assignment
- Gait Change - speeding to a gallop or slowing to a walk
- Adding a Rider on the back of your creature
- Extending the Cycle with non-looping behavior
Using the method demonstrated in class, move the horse forwards along a ground plane.
Dailies, work in progress - The Mighty Herd
WEEK 3 HOMEWORK:
Look at your reference for the horse trot again to add the final details:
- Offset and Overlap
- Legs lock when they go straight (study reference)
- Shoulders - scapula up and down (study reference)
- Compression in the hooves (study reference)
- Loosen up the head motion (study reference)
- Tail
- Make sure the feet are moving back in even increments (linear)
- Move the cycle forwards along a ground plane
Add a Rider: Constrain a humanoid character to the back of your trotting creature and animate them moving appropriately - they will need to cycle smoothly with the timing of your trot animation. Find video of folks riding horseback. How do they balance themselves and compensate for the movement of the animal? Make sure the movement of the rider matches the photo-realistic aesthetic of the mount.
Extend the Cycle with Non-Looping Behaviour: Take your cycle and duplicate it so it loops 10 times. Modify the animation to add actions that break out of the cycle and add personality to the creature. Some examples are:
- Adding a kick or a small hop.
- Head tosses.
- Looking left/right or up and down.
- Flicking the tail.
- Add any behaviour appropriate to the animal.
Change of Gait (Faster or Slower): Have your creature transition into a new cycle speed, slowing to a walk or speeding to a run/gallop. Use the same workflow to build the new cycle first and then manage the transition between. Refer to Stuart Sumida's great paper on animal locomotion for guidance on the mechanics needed for the transition.
Based on class feedback, refine your cycle animation and the extended elements. Continue to refer to your reference as you work. Follow good workflow practices for polishing. If you really want to polish your final work, a great tutorial for corrective blendshapes can be found HERE.
