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Walk Designer - Designing Custom Walk Cycles

Author: Cliff Bowman

Tools Needed

  • Poser 4 or higher

Introduction

This tutorial will lead you through the creation of a walk cycle for a character, which can later be used to animate that character in a variety of situations (especially following a user-defined path).

Although this tutorial uses the GIRL figure, the technique was originally developed using the African Elephant from DAZ, and is therefore not “locked in” to any special feature of any figure.

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Step 1 - SOURCE FOOTAGE OF A WALK

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This tutorial will cover how I create a custom walk cycle for the Walk Designer. This isn't the ONLY WAY to design a walk cycle, just one that I have found produces reasonable results.

I start with some video footage, prepared so that it shows a view of the kind of walk (elephant, woman, tiger - whatever) that I wish to reproduce. Ideally one would have at least 2 clips (from different angles - for example, from the side and from the front) each of which would have 30 unique frames and one extra frame, which is simply a repetition of the first frame.

In this instance the “source footage” of the kind of walk I need has itself been created within Poser 5 and rendered out. Producing source footage of other creatures requires a little more effort, and may be covered in another tutorial if desired. The source footage is stationary - that is, the subject remains stationary within the video clip - and can be computer generated, captured from film, or hand-drawn stick-figures.

Having loaded the figure I need to create the walk cycle for, and set the number of frames to 31 I set the Document Display Style to “Outline” and load the side source footage.

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This produces a very nice and useful reference for our efforts (which we can clearly see) but we can still improve on this considerably!

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Step 2 - ALIGNING THE FIGURE WITH THE FOOTAGE

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To make working with our figure easier, set the foreground colour of the Poser scene to contrast as much as possible with the background/source footage. Here I have used black as this shows up well. Search through the animation to find a pose which most closely matches the figures initial pose - here I have found frame 8 appears to be closest to a standing position.

Now that we can see our figure clearly against the background, ensure the Left Camera is selected and use the controls indicated to position the camera such that the figure matches with the background image as well as possible. Bear in mind that the “Hip” is key to Poser figures, as the base part of the model. Since we're designing a walk the ground and feet are also key - so if there is a “compromise” to be made in fitting, do your best to match hip and feet first, with other body parts (like the arms and head) matching less well.

You may well find that setting the values to the scaling and positioning dials to easily-read quantities (x.yyy, or x.yy, or even x.y) will be useful. Once the position is good, save the camera (to library or camera dots - or even jot them down on a notepad if the numbers are simple!!) and delete the key frame. Return to frame 1 and set the camera up correctly (load from camera dots, camera library, or type in the values you jotted down).

Step 3 - RINSE AND REPEAT

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Now switch to the Front Camera (or for some situations you might want to use the Top Camera), load in the background video that is shot from the front (or top!), and basically repeat Step 2. If you made very simple easy-to-repeat changes to the position dials then you can probably just type in the values for DollyY and Scale, as I have here, but if you didn't or if the footage doesn't match up QUITE correctly with the figure, adjust the CAMERA position until the hips and floor level line up correctly. Don't forget to ensure that there are no camera key frames left over by accident on either front or side cameras before we continue. You should arrive at Step 4 with the Front Camera selected and the timeline set to the first frame, as depicted here.

Step 4 - SHAKE THE HIP BONE

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Everything starts at the hip in Poser - and even more so in the Walk Designer. If your model doesn't have a “hip” part then it's going to struggle in the Walk Designer. So we start with the hip - the right leg is forward so as well as referring to the source footage behind the model, think about what is happening to the hip at this point in the walk cycle. The hip may be raised or lowered from default position, is likely to have shifted over to one side (more for balance than to “be sexy”), perhaps the hip has twisted slightly, thrusting the right leg forward. Don't worry about getting this EXACTLY right first time, just do a reasonable job - we'll review it later.

Make a note of your settings (or save them or…) and move to frame 16. Set the same values here, but reverse anything except Y translation. So you get the “mirror” position.

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You should switch to the Left Camera and import the side-view background video and check the hip position at frames 1 and 31 too. Although I don't feel the need to move the hip backwards or forwards at this point if you DO move the hip at all don't forget to check the same positions from the front view again. Work the two views back and forth until you're reasonably happy with the two positions. Make sure you're using the front view, on frame 16, before continuing with Step 5.

Step 5 - ENSURING A SMOOTHLY LOOPING CYCLE

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Load up the Animation Palette by selecting it from the Window menu…

A Select the Hip, frame 1, and then Copy.

B Select the Hip frame 31.

C Paste.

D Down at the bottom of the Animation Palette, move the “final” arrow from frame 31 to frame 30.

This creates a copy of the settings for frame 1 at frame 31, which will result in a nice clean 30 frame animation which loops very smoothly back to frame 1.

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Close the Animation Palette, and play the animation. Concentrate on the hip area, and make sure it flows as you'd expect before we move on. Make sure to regularly copy frame 1 data to frame 31 throughout the remainder of the tutorial to keep the animation smooth. If IK was turned on for feet or hands, you'll probably have a rather geeky dancing character now - a bonus animation! Turn IK Chains off before proceeding with the next step.

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NB For the ultimate in smoothness one could work on the middle 30 frames of a 90 frame sequence instead of the first 30 frames of a 31 frame sequence. In both cases we would restrict the playback to 30 frames, and in both cases we would eventually save just those 30 frames. However, the extra detail of dealing with 90 frames would increase the complexity of this tutorial without adding sufficiently to the quality of the animation. You may choose to work at 30/90 instead of 30/31 and adjust any frame number references accordingly.

Step 6 - POLISHING THE HIP MOVEMENT

So far the movement is deliberately simple, and is all produced at the hip. Now we need to add more data points to the hip movement to create a rounded, more realistic movement for the hips. There are two basic methodologies to this. The first is to select a frequency - every three frames, or every five frames (for example) and adjust the hip parameters at that frequency (e.g. frames 1, 4, 7, 10, 13, 16 and so on). The second method is to wind backwards and forwards through the animation spotting “key” moments in the animation, and setting values only as required. This second method relies somewhat more on experience with Poser animating than the former “plodding” technique so I would recommend choosing your route based on your own evaluation of your abilities at animating in Poser. I would however recommend doing the front view first, then the side view, then checking both until no further changes are required for that point before moving on to the next frame you intend to adjust. Do not make the mistake of setting key frames too closely together - it is very easy that way to end up with some very uneven movement that can be a nightmare to find and fix. Save your work often, with unique filenames.

I've used the “methodical” (OK, plodding!) approach, and sparingly - putting values at every 5 frames, except for the yTran value which I have set at extreme points (high and low). At any point it can be useful to use the “Graph” editor to check how smooth your movement is. Open the Graph either by double-clicking a dial on the “Properties and Parameters palette” or by selecting it from the “Window” menu.

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For me the Graph window always opens up displaying ALMOST (but not quite!) what I want to see. Grab the “handle” at the end of the “Scrollbar Thumbtack” (A) and drag it right to display the entire animation (B). Note that it CAN be difficult to make out frame numbers when you display too much in too small an area - but you can zoom back in again or select the desired frame number in various ways. Note too that you can select a specific parameter not just within from the dropdown list in the top right corner of the Graph window itself, but also by clicking on dials in the underlying “Properties and Parameters palette” (C). You can even change body part or even figure and the graph window will update with the current selection :)

The point of all this, of course, is that you can readily see exactly how smooth or jarring any specific parameters movement is. It's incredibly easy to select frame 9, enter a value, then select frame 25 and enter the same value, or to drag the value points up and down (even select a range and move it forward or backward in time). Get to know the graph - it's a very valuable tool for animating in Poser.

Note that I prefer to create “perfect” movement or models to start with, rather than asymmetric ones. It's much easier to add imperfections to a “perfect” (stylised/symmetrical) animation or model than it is to take an imperfect/asymmetrical model, pose, or animation and make a perfect/symmetrical version of that - or to make a completely different asymmetrical version! A “perfect” generic walk cycle should be devoid of “characterisation” that does not (or may not) apply every time you want to make that figure walk, and would act as a good base for more interesting variations once we've finished the generic walk. On this basis you'll probably find that you can only match your source footage about half the time. The rest of the time there will be visible differences because you're creating a symmetrical walk, and the camera angle, or the individual walking on film, or (so on and so forth) have resulted in a realistically asymmetrical walk. Bearing in mind that we can come back to the Hip later if it turns out not to be “ideal” (it probably will), let's close the Graph, briefly use the Animation Palette to make sure that frame 31 is an exact duplicate of frame 1, and move on :)

Step 7 - MOVING DOWN FROM THE HIPS

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Now we need to start moving down the body, working on each joint for the whole animation as we go. In my case, because I'm using GIRL to create this walk cycle, my next body part is “rButtock”. For other characters it might be “Right Thigh” or similar. In any case we want to work on just one body part, and work it front and side as we did with the hip until we're satisfied with the movement of the hip and buttock from all angles. Ignore the left leg for now - and the arms too for that matter. They will come later :)

Continue to work your way down the right leg, each time taking pains to pose the current body part relative to the hip and everything in-between but largely ignoring the rest of the body, until you come to the foot. The foot we shall take special care over, and exactly what happens there will dictate any adjustments we need to come back and make to the hip movement (and POTENTIALLY buttock, thigh, shin).

Step 8 - THE FOOT

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Before we truly begin Step 8, let's have a quick overview as it's potentially confusing.

First we'll discuss and setup some techniques for making the foot animation easier.

Secondly we'll animate the foot.

Thirdly we'll see how this impacts what we've done to date, and go back and tweak our earlier work to better fit the final foot animation.

LOOKING ALL AROUND

For the first time in this tutorial I'm going to insist we use another camera - the Posing camera. This camera has the beneficial distinction of not animating - so wherever you place it on a given frame, it will be in the same position in all other frames. This is quite beneficial when developing animation sequences! Set the Display Style to something a little more visible - Texture Shaded or Smooth Shaded, for example, and switch to the Posing Camera. Reposition the Posing Camera so that it's below the figure looking up, and make sure that Ground shadows are turned on. You should see that the Ground Shadows are clearly visible, but are broken whenever a part of the body (such as the left foot in the image) breaks the surface. This is Poser 4's hidden “collision detection” feature, in effect, and we can switch to and from this camera regularly to see whether our feet are reaching the ground or not. It is debatable whether we would want the feet to QUITE break through or not - a model with no shoes might benefit from JUST breaking the surface to simulate the flesh “squishing” as it impacts, while a model that might want to wear shoes, or which has hooves or is robotic, would likely want to remain completely above the ground at all times. the decision will be a matter for your artistic tastes and the requirements of the model you make a walk cycle for.

POSER 5 COLLISION DETECTION

Poser 5 has much better collision detection built into the program. If you have Poser 5 and a faster computer than mine (or a lower polygon-count model than GIRL) you may wish to add a square or a Ground Plane (A), turn on Collision Detection for all body parts (right foot, rToe, Square prop or Ground Plane) and either set Show Intersections (which does as it says, showing collisions in red) or Collisions On which in theory prevents 2 items with Collision Detection turned on from intersecting. It would seem inadvisable to turn this feature on with 2 objects already intersecting. Although I've used this feature in the past, Poser 5 SR4.1 performs this feature on my new notebook only grudgingly, and manipulating dials becomes a painful exercise - rather like trying to extract a rhino from a pool of treacle, in fact. So although Poser 5 can technically help here I will stick to using the visual check of body parts intersecting ground shadows. Much faster!

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ANIMATING THE FOOT

Now, returning to our walk cycle, we animate the foot. Proceed exactly as we have for the hip, buttock, thigh, and shin. This time in addition to trying to line up with the angles of the body in the source footage we have the additional task of trying to ensure that the foot makes contact with the ground when it is meant to (and ONLY when it is meant to) without passing THROUGH the ground. This ideal state - of the foot landing, moving backwards, then lifting cleanly from the ground is unlikely to happen correctly on your first go. The legs may seem too long, too short, or too numerous (grin). Don't worry - this moment has been prepared for.

RAISING THE HIP (OR LOWERING IT)

Once you've satisfied that the foot is moving correctly against the background of the source footage - that the animation is correct but the floor is stubbornly in the wrong place - we return to the Hip, and referring frequently to the Posing Camera adjust the hip's yTran values so that the body is at the correct height at all times, neither flying nor smashing the foot through the ground. Check through the animation frame by frame as well as playing it, and work through from hip to foot as many times over as required for you to be happy with the movement before proceeding to the next step. When the foot is connecting “perfectly” move on to the toe or toes, moving them at just the right time to prevent them from poking through. The added realism of having the toes bend correctly when a character walks is well worth the effort. It might be so subtle that you don't even notice it - one of the key clues to success (Big obvious things people notice - usually because they look faked!).

Step 9 - ANIMATING THE SECOND LEG

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It's taken us eight steps to get here, but we've finally made it to the second leg of our project. Ahem. So far it has been mostly a case of manual labour, even if we did manage a little copying due to the symmetry of the hip movement. But here we suddenly take a huge leap and copy the right leg movement to the left leg… So lets bring up the Animation Palette and get started.

If the left leg area (A) is not blank (apart from frame 1, which is always a key frame) please select the whole area and delete everything within it. Then increase the number of frames to 65 (B) to give us plenty of room - remember, only the first 30 frames will actually play anyway.

What we want to do now is copy everything that we've animated for area C to area A. There are a few problems though which mean it's not going to be quite that easy. For “Traditional” Poser models we can copy a body part at a time: select frames 1-31 in C, copy, select frames 1-31 of the left-hand associate of the body part and paste in A and paste. Repeat down the body parts.

However, models which use the “INJection” technology have added a lot of parameters to each body part which, if copied and pasted in this manner, results in mayhem. To work around this we have to open up each body part (click the little black triangle next to the body part name) and select the parameter we want (e.g. Twist or Side-side or Bend) and copy that, doing the reverse in section A. Repeat through all the parameters you've set (I've used just those 3) and then repeat THAT down the body parts from buttocks to toes.

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Oh dear! GIRL appears to have had a SkyBike accident. Poser can be quite good at automatically translating between left and right, but sometimes… well, let's go in and fix it. It's failed to reverse the “Side-Side” and “Twist” parameter values for every body part. It's simple but tedious to go through the body parts adding a “-” on every key frame for Twist and Side-Side that doesn't have a “-”, and deleting the “-” on those that have one. This reverses all of the twists and side to side motions, so that now we have what looks like a GIRL about to perform a swan dive. Save at this point if you haven't already, if only to keep this nascent bonus pose.

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Play the animation through, from the side as well, and ensure that the legs are moving “in synch”. Once it looks like you've evened up the movement (bearing in mind that the hip movement will make the animation slightly askew) select the entire left leg area, as shown in the figure, and drag it right so that frame 1 ends up at frame 16. Having done this, select what is now the column of lButtock to lToe at frame 31 and copy. Select the column lButtock to lToe at frame 1 and paste. Select the block of lButtock to lToe from frame 32 to frame 45 and drag it left so that it occupies the block from frame 2 to frame 15. Phew! If you want you can reduce the number of frames back down to 31 (I do this). Close the Animation Palette and play the animation - let's see what we've got! well, I've got a fairly nice walking animation, except that the upper half of the body isn't done and her feet slide through each other - she's got oversized feet! So I'll go back and edit the Side-Side motion of the buttocks, to bring her legs out a little further, then I'll recheck that her feet are hitting the ground and play the sequence from at least front, side, and a perspective camera before proceeding.

Step 10 - MOVING UP FROM THE HIPS

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Essentially now we work our way up the body from the hips. Abdomen first, then Chest, Neck, Head. Then work out one limb - Right Collar, Right Shoulder, Right Forearm, Right Hand. Copy the arm movement to the left arm and make corrections, exactly as we did for the leg, playing and saving frequently.

We have reached a crucial stage - we're almost done, but the next few seconds can make the difference between a great design that sometimes works and a wonderful walk cycle that works as reliably as Walk Designer does. First, save your file with a unique filename (so as not to lose any earlier work) then “Add your pose” to the Pose Library - anywhere except in the “Walk Designer” folder. Save all frames (1 to 31).

Having done that, load the Pose (“Apply Library Preset”, in Poser terms) at frames 31 and 61, adding to the number of frames in the animation each time. Using the Animation Palette to change the playback frames as we did earlier, but this time play from frame 31 to frame 60. Make sure that “skip frames” is turned off and play the animation checking for smoothness (turning Skip Frames off will most likely vastly slow down the playback and ensure that you cans see any problems with the animation).

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Assuming all is well with the animation, select “Resample Key Frames” from the Animation menu, and set the key frame frequency “1” (so every frame will be a key frame). Playback the animation, ensure it's running smoothly.

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This “every frame a key frame” step is necessary to allow users to try different variations of a walk with different timings. As every frame is a key frame the “old” version will always be completely overwritten (at least, to the end of the sequence - if you change GIRL from a slow walk to a fast run then there will be some remainder of the old slow walk after the run has completed). Add this final version of the walk cycle to the “WalkDesigner” folder in the Pose library, saving out frames 31 to 60! The reason for doing all this is that, as you're no doubt aware, Poser cannot judge what pose a character was in before frame 1 or what pose the character will be in after the last frame in an animation. We've been using an extra “frame 31” to smooth out the animation all the way through this tutorial, but if we have more frames after the animation AND a duplicate copy of the sequence BEFORE the animation then Poser has more than enough data to produce the “best fit” cycle sequence in the middle. When we set keyframes to every 1 frame, this locked the nice, smoothly looping frames to the appropriate values - and so it's this middle segment (frames 31 to 60) which contain our “perfect” walk cycle.

CLOSE POSER before restarting (this is especially important with Poser 5), then restart it. How well the various “tweaks” and blends may work with your new walk and figure, if at all, will depend on how different both are from the default Poser human figures AND on how closely your walk resembles the default human walk in Poser. Obviously a cow isn't going to respond as well to the walk designers various features as, say, a toon young lady is, simply because it is drastically non-human! The IDEAL situation to creating fully-featured walks for a character would be to craft several walks - normal, run, sexy and so on, although it seems unlikely that any one person would find all of the “usual” walk types interesting/useful, so ignoring some variations and perhaps coming up with some new ones would be a sensible approach.