3 Bone leg chain solved

Finally, I have created my 3 bone leg chain. The task was challenging. I could get away by creating a normal 3 bone IK leg as the proportion of all the leg joints in model were correct. I wanted a solid full proof IK chain where the leg joints would deform properly on rotation. I and Dipti discussed a lot on it and she gave me a solution which was complicated for my beginner mind. The ankle joint gets scaled with help of the reference chain if the deformation of the joint is not correct. With the scaling the the thigh and the calf joint never merges on rotation. This is the example of what I am talking.

Here, I created a 2 bone IK just like a biped and then created one more IK for the ankle joint. I linked my setup with a proper 3 bone joint setup which has a correct joint structure indifferent of my character design. Now my IK leg joint setup (according to the legs of my character) follows the reference IK joint leg setup and the ankle joint of my setup scales to maintain the angle of joints.

While I was talking to J about the issue I am facing, Jon suggested me to use the reverse foot technique for the 3 joint chain. He talked with me and Dipti about his logic and we stated digging into it as we both are crazy to find different methods/solutions. Yesterday, after coming back from Buffalo's I decided to stay at uni and work on the leg chain. I hacked it!!

This is what I have come up with.

I will discuss on how I created this soon...

3 bone leg chain or 2 bone leg chain?

After almost completing my leg rig, Dipti comments!!

Dipti- Your third leg joint is breaking, this is not correct.
Ruha- I saw few tutorials, they follow the same techniques.
Dipti- In prana these kind of characters were famous, so I am quite aware of the joint structure. You will have to create a 3 joint leg chain.
Ruha- Isn't there any other way, the DT tutorial have a horse rig and it works on 2 joint leg chain.
Dipti- That is a horse, your werewolf leg is quite different.
Ruha- @#$^, I am screwed. I have spend 3 days working out the IK FK leg and now I need to create it once again?

I am now tensed, very tensed.

I need to finish this rig soon, I don't have time :(

This is what I am talking about (I have send this question to the CG Coach tutors):

I created a 2 bone leg chain for the digitigrade , and for the third joint I added a separate bone like a human heel joint.

The issue I am having with two bone leg joint for the leg is that on translating the  leg on the right or left side the third joint doesn't maintain the angle, it seems like the leg joints are breaking. I quickly created a 3 joint leg chain to compare and show what I am talking about. What do you suggest in this, what kind of joint setup would be better?

Haven't yet receive any answer from CG coach, its been 6 days.

Why not an inverse foot 2 joint IK?
  -Because you need to manually rotate the last joint every time you translate the leg. Although its easy for me and the animators are acquainted to the inverse foot, I want to go more advanced and discard the need of creating and animating one more control. Knee and ankle are always linked together, so a setup is required to automate their relation.
  -Now if I create a 2 bone IK, it should effect the complete leg, that is the knee as well as the ankle.
  -The leg should remain STRAIGHT when you translate the IK

These are one of the prime reasons why I am researching on digitigrade leg rig which has 2 IK but still works like a 3 bone chain.

Rigging Begins

Until now I have created almost 3 versions of the werewolf leg. Every tutorial has a different technique and it doesn't seem to be a proper clean rig. I need a simple rig with advanced controls giving complete freedom to the animator to use the controls for animation. I don't want automated stuff like my previous rigs for the group project.

Everytime I have created the leg rig, I have learnt something new about rigging. It seems as if I am researching different techniques along with rigging my character. Most of the tutorials I found online for the quadruped (as my werewolf has digitigrade legs) are for horse and the leg structure of the horse is a bit different and this changes the approach for the rig.

While I was rigging, I discovered few things. I will consider them the golden rules as I am a newbie.
1. Always always always create your leg joints in LEFT view.
- What would happen if I don''t do that?

 

You get the wrong axis for the joints, you Y axis faces negative. This might create issue while rigging, the most important thing in rigging is the joint orientation.

2. In softimage, keep the Align Root to First Bone when Drawing ON
3. Your controls should be aligned to your joints.
4. Keep separate layer for joints and controls.
5. Never mess with the resolution plane and roll of the lower bone for the leg. It will restrict the knee from moving along with the IK and won't change even if you undo.

I will keep adding more as I discover.

Animation

Animation References-


The animation is about a werewolf running through a landscape like a biped and then change to a quadruped run. I have chosen this act to show smooth transition of the rig from biped to quadruped. As there are no real footages of werewolf running, I took reference of canine run (Video 1) and human run (Video 2) to study the motion. I found some references of people walking with homemade digitigrade legs (Video 3). I also found few references of people running like dogs, which were the key reference for my animation sequence (Video 4, 5).

Animatics-

These are the thumbnails I created for the animatics, I am not very good at drawing but this gives me an idea of how the animation would flow.

 Line of Action

Modeling the Werewolf

Version 01-

I wanted to concentrate on the rigging and animation, so I decided to create the model using already build models and tweak them for the desired look. During the Easter holidays, I started creating the model in Softimage. I collected online images of werewolf and used it as a reference to create the model. Most of the images had a heavy beastly look for the werewolf and I went along with the references. I retopologised the Softimage human rig model for the body and tweaked it to the kind of look I wanted for my model. For the face, I found a 3Ds Max model, but the topology of the mesh was not correct at all. I imported it into Softimage and started retopologising it, but at some point, I realised that I will have to create the face mesh from scratch itself. I used a canine leg mesh for my model, which was still work in progress, I was not satisfied with the topology as it was too complex and I didn't need that level of complexity in the model.

The following are the images of the model (WIP) I had created by the end of Easter holidays.

Version 02-

During my second presentation after the Easter holidays, I told everyone about the change of concept. While I discussed the new concept, my tutors were not quite happy with the design of the model; it had a typical Van Helsing werewolf look. They suggested me to explore at non-conventional werewolf designs like the werewolf in Harry Potter. They advised me to revise the character design with a skinny and lean look. I am planning to add a deformation rig for the muscles, so reasoned why I needed a body builder kind of character. Saf mentioned that Bruce Lee has muscle and they are obvious but still he does not have a heavy look. I too agreed to his point and understood the difference a unique character would give to my demo reel.

I decided to freelance the model to my friend Samir and invest more time into rigging research. I sent some reference images to him addressing the kind of look I wanted and sent him other research materials for the anatomy of werewolf. After few days, he did send me a model, but he did not follow the specifications I had given him. I cannot use this model though it has a good topology, as it looks more like a human-dog rather than a werewolf. Following are the images of the werewolf model he had created.

 

Version 03-

This is my final version of the model.

I had to correct the topology of the torso as it is very important for the deformation ig. I decided to spend more time correcting the model so that during the rigging stage I wouldn't face much troubles.
My turntable for the model-

Locomotion of Werewolf

The movement of werewolves is discussed either in films, mythological books or by fictional story writers. Being combination of human and wolf form, werewolf adopts locomotion characteristics from both. According to the old true story of the famous French werewolf “The Beast of Le Gevaudan” there were reports that this werewolf was able to move both ways in biped and quadruped form (Eric, N.A).

Werewolves have a bipedal skeletal structure and so they prefer a bipedal position, it is still an odd, uncomfortable position, so they prefer to slouch. They have digitigrade legs, so they walk and fight on twos and run on fours. They have the ability to drop to four legs for short bursts of speed. The human back and pelvis are not meant for this type of running, unlike the canine pelvis which is actually almost ninety degrees angle to the spine, the human spine and pelvis are lined up for walking upright. This form of werewolf would have some dexterity like humans and an advantage to bite, claw, and savagery like wolf making it very dangerous beast.

The shoulder blades of a werewolf are on the sides of the rib cage near the back, giving the werewolf a sort of hunched appearance. Going on all fours simply means moving the blades farther forward along the rib cage, to give the forelimbs the necessary extra length. The advantage is, the werewolf can climb angles that are impossible for humans to climb, while still capable of standing erect when desired.

One of the important questions about movement of werewolves is whether they walk on knuckles or palms. Knuckle walking is when on all fours, animals use fingers of their forelimbs rolled into the hand, putting pressure on their knuckles. This might lead to problem with the movement of wrist in long run due to heavy pressure. Knuckle walking tends to evolve when the fingers of the forelimb are specialised for tasks other than locomotion on the ground. For example, gorillas use fingers for manipulation of food. While walking on palms would be easier for werewolf as they have pads to increase friction and larger wrist in comparison to a normal human hand to take load on the heavy body. I explored for some reference on human running on fours and in most of the cases; I found them using their palm rather than knuckles.

A werewolf walks quite different from a human, for example-A human puts his foot down, pivot at the ankle, and then put the other foot down. While werewolves put the foot-paw down, pivot on the foot-paw and ankle simultaneously. Humans sway from side to side while walking, whereas werewolves move slightly back and forth. Most of the body motion stops at the waist, leaving the upper body fairly still.

Werewolf Anatomy

A werewolf is a fantasy creature, which has a form that is a combination of a wolf and a human. A werewolf is considered to be one-and-a-half to three feet taller than a normal height human.

Since the werewolf is still bipedal and half-human, much of the muscle structure is similar to a human (Figure 1).

 

Figure 1: Muscle structure of human (left) and werewolf (right) 

The werewolf skull in comparison to the human skull is quite different. The cervical vertebrae are more similar to those of canines than human. When on all fours, they appear to have a very long neck; this changes when on all fours. The jawbone is longer than human and the eyes occupy a larger region of the skull (Figure 2). 

  

Figure 2: Human and Werewolf skull 
 

The lower skeletal structure of werewolf is more similar to quadruped than biped (Figure 3). While they show a wider range of flexibility in their hip joints, they still have restrictions such as the high hock and stifle, preventing full bipedal movement. Though the hock is lower than that of normal quadruped, it still doesn't show the characteristics of the human heel (Nylak, 2006).

Werewolf have legs those of a wolf, although they are upright and mounted more like human legs. Werewolf's feet structure is highly similar to that of a quadruped, exhibiting only four toes and is slightly bulkier to support full body-weight on two feet (Figure 3).

 Figure 3: Lower skeletal structure of werewolf (left) and canine (right) 

 

The hips of the werewolf exhibit femurs in which the ball joint sits slightly to the outside of the knee. However, the angle of the hock cannot reach 180 degrees, creating a slightly hunches-over posture that is necessary to maintain balance while standing on two legs (Figure 4).

Figure 4: Ball joint position of werewolf 

The scapula of the werewolf is not closely attached to the trunk as quadrupeds, and the glen humeral joint allows 360-degree movement. Similar to the extended femur of the werewolf's leg, their humerus (upper arm) is also longer than that of quadrupeds (Figure 5); the arms have structure similar to that of a human. The ball and socket joint of the elbow has a 180 degree range of motion (Nylak, 2006).They have pads on their palms and distal phalanges, but on their metacarpals, as well (Figure 6).

 

Figure 5: Upper arm of werewolf (left) and quadruped (right) 

 Figure 6: Werewolf padding on palms (left) and Canine front paw padding (right)

 

SWOT analysis

SWOT analysis

Strengths

• Previous experience of rigging in Group Project.
• My programming knowledge helps solve technical issues.
• Having animation experience helps to give proper functionality to the rig.
• I am very enthusiastic about rigging which allows me to work for hours without getting tired.

Weakness

• No industry experience in rigging.
• ICE and SCOP are completely  new concept for me. 
• Don't have much knowledge for modelling, I need to have proper loops for deformation rig.
• I don't have complete knowledge about the strength of the Softimage in relation to rigging.

Opportunities

• Bi-quad rig will give me knowledge of both biped and quadruped rigging.
• Gain in-depth knowledge of animation rig and deformation rig.
• Create a unique rig which will save production cost.
• Chance to do self research and gain understanding of human and animal anatomy.
• Create a Rigging show reel to get job in the industry.

Threats

• Might not be able to successfully create the multi-way constraint with help of vector maths, I will have to compromise with constraint blending to switch the parent.
• Possibility of the rig to break because of implementing multi-way constraint.
• Will not get proper deformation if the loops of the model are not correct.
• Not enough time to create more animation to closely show the deformation in the rig.

Master Project Brief

My project is about creating a Bi-Quad rig with both Biped and Quadruped functionalities. My rig is based on a werewolf character which can move on twos like a human and fours like canine. The fluidity between the performance will be the characteristic of the rig. I will be creating an animation rig and a deformation rig for the character. In order to test the rig, I will create a five second animation of the character running through the forest in twos and then changing to fours. I will also submit a Camtasia for my rig to show its functionalities.

My main aim from the master project is to create a high quality character rig to portray my technical skills for the demo reel.