The Stalker

Artwork Works in Progress
1

Here it is, a fully rigged walking mech-thing. easily the most complicated model I’ve made.

So complicated that I’ve run into a few problems.

First up, I’m trying to animate this thing clinging to a ceiling then dropping down. The problem is that whenever I flip the armature over, it freaks out as the rotation approaches 180 degrees. The only thing I can think of is that maybe I’ve done something screwy with the IK constraints, but I have no idea where to start looking.

The second problem is that I’m trying to mix IK and FK animation. This thing is supposed to be able to fly or walk. The problem is that I’ve found FK to be much easier for the ‘flight’ animations and IK to be much easier for the ‘walk’ animations. What I tried to do is make the ‘walk’ animations first, keyframe all the joint rotations, then disable the IK and do the ‘fly’ animations. The problem there is that, despite keyframing, my ‘walk’ animations break whenever IK is disabled! The bones aren’t considered to be ‘rotated’ when they follow an IK target, so there is no rotation stored in the keyframe for that bone - just the location of its (disabled) IK target. Not sure how to fix this.

I’m still proud of it, but it’s driving me crazy!

Once I get the animation issues straightened out, I intend to add interchangeable weapons.

No plans at the moment to add textures, due to having the art skills of a blind caveworm using an etch-a-sketch.

Attachments




2

do you have a root bone? it is good practice to have a root bones and have all bones in some way connected to it

for example:

Root>hip>thigh>calf>foot
Root>Shoulder>arm>lowerarm>hand>fingers

basivly everything should be under “Root” so that you can move the entire armature by just moving the root bone.

3

I have a bone called “Fuselage” which everything is connected to, but when I rotate it only the vertex group ‘Fuselage’ moves due to the IK constraints on the feet. I have a set of ‘dummy foot’ bones that are the IK targets for the tips of the legs, and a set of ‘end rotation’ bones which control the rotation of the feet (to keep the feet flush with the floor while they follow the dummy foot bones). In order to flip the model upside-down, I have to rotate the entire armature in pose mode so that the ‘dummy feet’ and ‘end rotation’ bones end up where they need to be. The problem is that from about 170 degrees on my model starts acting like it’s having a seizure until at 180 degrees the model is tilted at a 135 degree angle with its legs twisted like pretzels.

4

The hell!?

I added a new bone, Root, directly above fuselage, and now it works.

Before, the heirarchy was:

Fuselage > Everything Else

Now it’s Root > Fuselage > Everything Else.

Oh well. Gift horse + Mouth = I’m not looking. Thanks for the help! Now I just have to figure out how to mix FK and IK animations without breaking anything.

5

There is a thread over in rigging help that may interest you. They have just been discussing switching between ik and fk cleanly - starts about half way down the page
http://blenderartists.org/forum/showthread.php?t=158111&page=8

6

Thank you very much! I missed this while looking through the tutorials. I’ll post again if this solves my problems.

7

Alrighty! Just a quick post on how the problems were solved:

  1. The “No 180-degree Rotation” problem. I added an additional “Root” bone above all other bones. This solution bothers me, because I already had a “Fuselage” bone above all other bones. Logically, this shouldn’t have worked… but it did. Oh well.

  2. The IK + FK problem. Surprisingly easy. For the IK-based animations, I added a channel for each of the IK constraints and made sure each constraint was keyed to 1.0 for it’s influence on the first frame of animation. For the FK-based animations, I did the same thing and keyed each constraint to 0.0 on the first frame.

I’ll be posted a few finished animations later tonight after they’ve had time to render!