Saturday, 5 February 2011

Introduction, Research and First Tests.

Introduction
In this blog is the work I have produced for a walk cycle animation project. The objective is to get an understanding of how animated characters walk depending on what personality they possess, learning the techniques of producing a sufficient walk cycle and using those techniques in our own work.


Research


For the research, I decided to look on YouTube for clips of walk cycle tests done by other people. Below are a few links to a couple of these examples, all of which are quite interesting.  I have noticed that one or two of have shown mistakes in animating them but nonetheless they are quite good. Also are some links to websites for walk cycle tutorials, all of which gave me a better understanding on how to produce a better animation test.

YouTube References

Tutorials

Also, another method I used to get another idea of how to produce a walk cycle is by performing in front of a camera myself. As viewed in the clip above, I did some walking in and out of the room at different speeds, just for the first test of a walk cycle, all the personality tests will come later on.



This is a rough chart I personally sketched to practice my skills in drawing as well as be a bit more authentic.  This image shows a layout of the different positions in a normal walk. I like to note that there are some mistakes I have made in this chart, such as when I could have lifted the leg a little higher and bent it more, but of course that could be fixed later. 

  1. At the start of the image, the character is in the contact position, which is of course where his foot in front hits the ground and his back foot is about to rise up.
  2. The next is the down position, where his front foot is completely flat on the ground, putting all his weight in that leg and the tip of his back foot is just leaving the ground.
  3. Then there’s the passing position where he is halfway through the step, his leg should be at its highest point as he swings it forward.
  4. And last but not least, there’s the up position where he is leaning forward on one leg and he is about to bring his other leg down in front. That gets him back into the contact position where the cycle repeats with each leg.


Second chart I produced, which I would use as reference for the next walk cycle test.



This here is just a rough animation test, using the images of the walk cycle chart I produced earlier on.












According to Richard William’s book “The Animation Survival Kit” as well as observing several clips of his documentary, I discovered that the velocity of the walk depends on how many frames are used in each step.

It seems that people usually walk in a different manner from one another. This usually depends on their personality and their physical stature. They also appear to walk to a beat, varying in tempo. When you animate a character walking along, you usually have it walk at a 12 March beat. So to speak, you should have the character making 2 steps in a second, which means that every 12 frames, his foot in front should contact with the ground. 


Below is a chart of timed out walks, from fastest to slowest.

4 frames – Very fast run (6 steps a second)
6 frames – Run or very fast walk (4 steps a second)
8 frames – Slow walk or ‘cartoon’ walk (3 steps a second)
12 frames – ‘Natural’ walk, business like (2 steps a second)
16 frames – Strolling, leisure (2/3 of a second per step)
20 frames – Elderly or exhausted person (almost a second per step)
24 frames – Slow step (one step per second)
32 frames – Slow motion.




Here is the very first test shot of a normal walk, using Toon Boom Studio. As you can see at the bottom of the clip, I decided to mark where the foot hits the ground so to show how many frames each step lasts. My stickman is walking two steps per second, which means his foot would contact with the floor every 12 frames. Of course, a few adjustments need to be made for the next test shot.


This is the next animation test, produced with drawing figures from the previous chart onto tracing paper, then scanning and compositing in After Effects. Notice that I have marked a certain frame of each time the character's front foot makes contact with the ground. Just another technical thing I added in.


Perspective


The next stage was to produce a clip of a perspective walk, which meant my character had to either get smaller as he walks away from the camera or get bigger as he walks towards it, giving off a depth of field.
Here is a rough chart I produced of a perspective walk to use as a guideline for the animation shot. I used the same techniques and positions for making a regular walk except as I wanted the character to walk away, I made each image smaller than the previous one.

Personality



Here is the shot of a 2-D perspective walk I produced. As you can see, I have added some guidelines (literally) in the next half of the clip in order to show more of the perspective. Once again, I used tracing paper and pencils to animate the character, creating the key drawings first and then adding in the in-betweens. Then I scanned them into the computer and composited them in After Effects as well as adding other images.



This next clip is my first personality walk cycle shot. I have decided to produce a sad kind of walk for this as I assumed that a character in a state of depression would be one of the easiest to do. So I managed to produce a walk where his back is slightly hunched and his head is drooped downwards, flapping up and down as he walks and the arms don't move very much either. 
Since a person walks slower when they are sad, I did this clip in double frame which means I had used 12 images in one second, two frames for each image to make it run not too fast. Another way to create a slower walk is to add more in-between images but I decided to go with double frame as I wanted to get an idea of how the walk would look.


More work in progress...

Friday, 4 February 2011

Maya - 3D Tests

Next are the walk cycle shots I produced using a reference file and information from the book, "How to Cheat in Maya" and of course Maya 2011, without which none of the 3D shots are possible. 

This clip is a just a character walking against a simple background from the right to the left of the screen. By following a chapter on walk cycles, I was able to produce the walk by using different postures and keyframes throughout the sequence. Noteworthy, although I set keyframes from one contact position to the next, I was able to loop this sequence by selecting "Post Infinity - Cycle" in the Curves box of the Graph Editor. Since I haven't been able to move the character off the spot just yet, I have simply created the illusion of him walking from one end of the screen to the next by setting keyframes for camera movement. After exporting the clip as JPEG files, I put them into a sequence in After Effects, looped them a few times just to make the duration longer and then exported the whole sequence as a Quicktime movie file.

This clip has the same character in the same sequence, except with a different camera angle. This is a perspective walk, similar to the 2D one I produced earlier except I found this one easier to achieve by simply moving the camera.


The same walk cycle, except I had set the camera at a high angle.

This here is my personality walk where I decided to give the character a happy mood. For this shot, I decided to have the character perform in this order; walk up to a step, step on top of it, look over to the left and then attempt to jump onto the huge table. I managed to achieve this by using a series of keyframes and positions, despite a few complications. 
Being critical, there are some parts of this clip, as well as my other work, that could have been improved but due to time issues, this is the best I can do for the time being. Need to learn more about Maya and do more practicing.