07 July 2006, 03:30 PM
please .. anything counts ... any idea how to rig that quad leg. that's all I need ... everything else I can setup myself ...
07 July 2006, 04:13 PM
I was going to develop a website specifically on how to build horses, but it was going to be more geared towards realistic horses and how to effectively gather the necessary resources, choose appropriate reference material depending on what the horse is for, etc.
Right now I'm developing a custom script to allow very detailed control of fur flow, color, coat markings, etc.
As for rigging, to me it seems fairly straightfoward, as long as you're familiar with the structure of a real horse, the range of motion of its legs, how the legs merge with the body, how the joints change shape with rotation, etc. I've mentally worked out a few different ways to achieve the small compressive neck wrinkles which occur when the neck bends, etc.
Bear in mind that horses have four natural gaits, and some breeds have additional natural/trained gaits. The four natural gaits are: walk, trot, canter and gallop. Creating the transistions between each could be difficult. Also, some other classic moves are the piaffe, sidepass, rearing, bucking, etc.
To add a great deal of character and/or realisim to your horse rig, I would not underestimate the importance of creating ears which can rotate 180 degrees (independently of each other), as well as have a general understanding of how and why such ear movements occur.
In another thread I posted some information and links to videos showing various movements, and I'll repost that information verbatim here:
Here are two videos (more to follow). They illustrate points or show subtle capabilities that you might not be aware of. Unfortunately they are very small. I found some more videos at a couple of sites (pretty good ones too) but no time to post them right now.
This video shows a Quarter Horse going through cavaletti poles. The first half of the video is fluff, but watch very closely the second half. The horse does a trot through the first set and then enters into a canter for the rest. Watch the accurate foot placement for both gaits: http://www.aqha.com/showing/shows/worldshow/winningrun/amtrail.html
In the next video, watch as the horse does the sidepass. (the horse goes sideways) Pretty cool, eh?
In this next video, the horse is doing a half pass - which is like a sidepass, but not totally sideways - instead it is half sideways and half forward. In the video the horse is doing it at a trot, but the horse can also do it at the walk and canter.
Ok, the next one is going to be confusing untill you understand exactly what you're looking at and why it is significant. So let me give you some background.
As you might know, the trot is essentially symmetrical from left to right - in other words, the legs on the right side do the exact same kind of motion as the left side, just at the opposite beats of the gait. In other words, in a trot, the front legs go: left forward, right forward, left forward, right forward, left forward, right forward, etc.
But the canter and gallop are different. Each side is doing a different type of movement unlike the other side. For example, the front legs go like this: left front leg leads out far, right front leg then goes out not as far, left front leg leads out far, right front leg goes out not as far, etc. In that pattern in a canter, we would call that a canter on the left lead. A horse can do either lead, left or right, and can be directed to whichever lead you desire.
Ok, now, as it turns out, when turning in fairly tight turns, one lead is better than the other depending on which way you're turning. So enter the classic figure eight pattern. Since a figure eight pattern has both a left turning half circle and a right turning half circle, it follows that optimally, the horse would change leads from one to the other each time he crosses the center part of the figure eight.
Now, note that the horse can do both turns with a single lead - it's just better if he changes leads - it results in a smoother turning feeling. So, we come to the flying lead change. That's where the horse changes leads mid stride without missing a beat or slowing down. The horse can be trained to do this on a cue.
Now, let's take that to an extreme just for exhibition purposes. We won't ask the horse to do a figure eight, but just go straight and do a flying change with a one tempi change, which is to change the lead every stride. This next video demonstrates it. Watch closely as the horse does a very slow canter with a one tempi change.
Here is another video of the same thing:
And here's a video of a flying change with a two tempi change, or changing the lead every other stride:
That brings up another point which you've probably detected. The horse can be asked to engage in the different gaits at different forward speeds. In other words, the horse can nearly canter in place, or canter at a fairly good speed. Same with the trot and walk. When a horse exhibits a trot with strong impulsion, it appears that the horse is effortlessy moving forward and floating just inches off the ground. It is astounding and beautiful to watch. It is called the floating trot, and unfortunately I haven't found any videos which perfectly demonstrate it yet.
Some other videos that I'd like to find are of cutting and the pirouette, as done by western riders, which is not exactly what is available to watch on the dressage animated gifs, which is the canter pirouette.
You can follow my WIP from my sig, but it's mostly just geometry right now.
07 July 2006, 11:33 AM
thanks a lot for all this reference .... this will undoubly be very useful.
one thing though that I need in order to get to animation is to find out how to rig the legs .. so some guide in this direction would be helful too.
I already have my model finished. But cannot find some comprehensive tutorial on rigging ... all TDs just say that it is easy, focus on this and that ... but not really a step by step guide whith would guide ME ..
thanks a lot for your great reply
07 July 2006, 03:37 PM
Here's my advice:
Take 30 minutes to google 'horse conformation' and get familiar with a conformation chart, and the various components of a horse. Knowing a name for a part of a horse makes that part more real in your mind, makes you more aware of it, and thus makes you better understand how everything works together. This will help you in rigging. Without a doubt, you should know what the hock is, the poll, the stifle, the fetlock, the croup, and so on. This will be 30 minutes well spent.
Since you say your horse is funny in proportions, I'll assume it's deliberate, so you probably aren't that interested in making sure your horse has a proper conformation, but still, as noted above, get familiar with the terminology.
Then google 'horse skeleton' and get the best skeletal references that you can.
Now, armed with skeletal references and your newfound knowledge on horse terminology through your study of conformation charts (do not skip the 30 minute conformation study!), you have a set of terms that you can search on. By combining those terms with words like 'action', 'canter', 'locomotion', etc., or just searching on the terms by themselves, you'll better be able to uncover some sites that feature excellent pictures, diagrams, etc., showing various closeups of said item in action.
I would look into experimenting with a 'reverse foot setup' for the fetlock, except it would be reversed from its standard usage on a human. When I say 'reverse foot setup' I am not referring to a reversed fetlock angle, but a standard way of rigging feet on humans. Google it.
Make sure you add the 'S' curve on the horse's neck vertebrae, to enable the nose to reach the ground. Study 'dressage' pictures to see what a composed and arched neck should look like. Study racing pictures to see what a horse looks like at full gallop. Study hunter/jumper pictures to see what jumping looks like. Study cutting/reining pictures/videos to see what agile turning on the hindquarters looks like.
Anyway, rigging starts with understanding your subject. If you already know a lot about horses, then forgive me for telling you things you already know. With regard to the technical aspects of rigging, don't underestimate the value of getting your joint transforms oriented correctly from the start. Use a 'jointOrient' tool for this, but first be aware that certain joints on the horse need special attention, such as the hip and stifle.
So, I'd search for rigging tutorials, and general and specific horse information sites, and then combine the knowledge from both domains to create your rig.
07 July 2006, 04:54 PM
Well, this may be a good start for you.
Tyler Thornock rigs
He has some sample rigs and one of them is a horse. It could be simplifed even more. You could have just one IK chain to the shoulder and then have FK controls that rotate the clavicle and shoulder blade. This will give you much more control. A Horse's upper leg movement is very slight. Those muscles are so big and strong, they are not that flexible. All the mobility is in the knee and ankle. Same goes for the rear leg. The hind portion does not move that much in relation to the rest of the leg.
I really struggled at first racking my brain around this but after working with the animator, simple is really the best. May be a few extra controls to animate but has the best overall control.
Hope this helps some.
07 July 2006, 06:45 AM
thanks again for all that great guide. Have to say this is my first animal character and having so many different parts to look at (well not that many new just two more legsL-) makes it somewhat difficult to concentrate on what's happening ... to me. So really thanks for telling me what to look at ... very useful help.
I have access to some 15 horses (family business Horse Academy) but these notes of yours will guide me to look at them with more attention and detail.
very good point with that one IK chain and FK rest ..... that makes things a lot easier to rig and even animate. Originaly I was looking for that sophisticated system of having one IK at the bottom and moving those 4 joint in one move and still realistically .. but this thing will do.
Unfortunately the rig is for Maya 7 on WinXP and I'm with Maya 6 on OSX ... so the file is crystal clear when opened.
Thanks a lot guys for your advice ... take care
07 July 2006, 06:45 AM
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