AT-ST

Good day people. Okay, as complained and requested by mr.meteor yesterday morning, here is a more elaborate breakdown progress of the AT-ST i'm working on. So far so good. Have been rigging the model for two weeks now and i'm feeling pretty good about this baby.

Not much of a skinning skinning going on but more calculations and thinking needed to constraint this and that. Here is a simple tiny walk of the AT-ST...



Well, this is not the final walk-cycle of the fella...as the Foot-Roll wiring is still under-process. Slacking abit larh but will finish it up soon.

Here are some breakdowns of the small small little details in the foot rig.

This clip below, you can see the stretch and squash of the cable at the knee-joint.



Each end of the cable is attached to a dummy point; that each dummy are respectively attached to the different part of the AT-ST leg. By using a SplineSelect; select a vertex end of the cable and attached it to the dummy by applying a Link XForm.

By doing so, the vertices will follow the position and rotation of the dummy. As the dummies move closer to one another, the cable will deform accordingly; whereas it will stretch accordingly when the dummies seperate.

Next, this shows the mechanics going on at the back of the knee area. You will notice the two metal plates reacting to each other's movement. The lower part of the leg will push the upper metal plate outwards as it rotates itself forward.



This little fella is alittle bit tricky. It has got to do with wiring calculations of the positions and rotations of the x/y/z axis of the two components. As the entire leg uses IK chain properties, the lower leg doesn't rotate if manually controlled. Therefore, we will need to calculate the pos/rot of the controller moving the IK chain in reference to the upper plate rotation contraints. There are still things need to be resolved here. To put it simply, headache`

This last clip below shows the motion of the pistons.



The pistons are basically two cylinders each attached to a dummy point. The dummy points are placed on both ends of the motion; one attached to the thigh-leg of the AT-ST while the other to the uppermost leg connected to the pelvis of the robot.

For the pistons, we use the LookAt constraint for the orientation. Basically if piston A is attached to dummy A, it will then have a LookAt constraint to dummy B. While piston B attached to dummy B will have a LookAt constraint to dummy A. What it does is that, however the animator positions the AT-ST, the two piston cylinders will always be looking at one another.

So, that's the end of my little breakdown of the AT-ST as requested by mr.meteor. I'll probably talk more about earthly matters on the next writing. Have a smooth-sailing week ahead`