We'll start with Quadruped Trot (or run).
Here again, a good idea is to find life action footage with trotting horses and work it out the way
I explained in "working with life action reference" post.
Then look at the picture below and answer the question: Which drawing will better illustrate the trot, 1 or 2?
Ritorical question, 1 it is.
Let's start with it.
First we need to familiarize ourself with the model. I use simple and easy to animate model I call "Donkey". Clicking on head, shoulders, low back, clavicles, hips and legs doesn't reveal any parenting, only IK/FK on the legs. (pic1). I dislike parallel legs on Pic2 and would recommend Pic3 instead.
pic1 pic2 pic3
Create Quick Select Sets and we are ready to animate. We need 16 frames for the trot. 16 is easy to divide (16, 6, 4,2).
Create an air born pose. Keep in mind that the strides of all four legs must be equal in lenghth. Pic1, where A=B is good. Pic2 is not.
pic1 pic2
Another suggestion: Please look below:
pic1 pic2
I used two methods when creating the legs' position. Red circle is where I used hoof Rotate X (pic1 above) and I would NOT recommend it. If possible, use Toe Roll, in Yellow cirlce. Just like in pic2 above.
A few more notes:
1. Don't use the Root to move the body up/down. (in blue circle below). Use Chest and Hips (in yellow rectangles). This will give us a chance to off-set back from the chest later and create more lively movement.
2. While making steps, try to shift the bases of the " red triangles" back a little. It will help
passing postions (yellow lines) to slant back and create unstable, leaning forward feel.
After creating jumping pose on frame 0, select all controls from Quick Select Set in
Outliner (blue highlight below) and check Graph Editor. If the lines are waive like, use the autoTangent button (in red circle) to fix them.
Click here
Let's call it "Rough timing and spacing". It has only extremes.
Let's call it "Rough timing and spacing". It has only extremes.
Now it's time to create passing positions. Refer to my wonderful picture way above that I started with. We'll create pose number 2 right in-between the extremes.
"Forward" legs, ones that "travel" back (red arrows) should be placed straight on 0 (yellow rectangles)
Now we need to bring the body down (red arrows below) and work with the passing legs to
make them more natural (red circles).
Same with the second passing position and we are done with the blocking.
Click here
Click here
Of course, we need to do something to the head and tail. The general rule is "When the body moves up, head moves down and vice versa".
To complete our blocking, we need to look at the weight shift during passing positions, when the body of our Donkey must be supported by the "grounded" legs.
Red arrow (below) shows the shift of the chest. Please look at the Graph Editor,
Red Circles show the slanting of the tangents. Don't leave them flat.
Same should be done to the low back with the result.
Our rough blocking is done.
Next stage is working with in-betweens, creating feet contacts, "pushing off" the ground, head overlap and, if you are so inclined, tail movements. One can also look at compensating of the left/right neck rotation etc. But all depends on the rig. Our rig is rudimentary and it is nearly impossible to create "realistic" polished animation with it. But we'll proceed with the in-betweens.
On frame 2, forward legs should be already on the ground.
If necessary, we may work with clavicles a little (red circle) to avoid stretching of the
legs too much. We may also rethink how high the body is in the air in our extremes.
On frame 6 the feet still should be on the ground, pushing the body forward and up.
If the leg can hardly reach the ground without stretching too much, first line of "defence" is the Toe roll. Second trick is to work with clavicles, third - rethinking the length of the stride and up/down movement
of the body.
Don't forget to always check your splines in Graph Editor.
We're done with rough animation. Time for some polish. How about head overlap?
We can delay head rotation in all in-betweens.
Picture below is self-explanatory.
The last, but not least, is to make sure the translation of the feet on the ground is done on the straight lines.
Let's make sure that all the controls of the legs are keyed (When we Zeroed Ty in channel box, Tz was not keyed and we need it.). Now compare Tz of all the legs and:
a. make sure the segments of the curve, where legs are on the ground are straight lines.
b. make sure the legs travel the same distance.
c. make sure all the straight segments are parallel to each other.
Front leg is "pushing" the ground back. Yellow marks are straight part of the motion.
Select the tangents and make it straight by using the button in yellow circle (below). Doesn't look like much, but if you use your cycle for moving across the ground by translating the World, this will be important. Otherwise the feet will be sliding.
Same needs to be done to all four feet.
Now we select all Tz in Graph Editor and make sure they are parallel to each other. Tweak them, if needed.
Looks like they are parallel.
The more tweaking you want, the better rig you need. After we are done with the tail and off set all animation of the back one frame forward this little "Donkey" has served it's purpose.
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