Getting somewhere

I kept changing what bones point at what empties, because the mocap system armature we used has a different number of leg bones, it's really a case of seeing what works best.

I finally got the armature to follow the empties, it wasn't working because I hadn't put the right constraint in. I needed a copy location. It was now following, obviously I need to tidy up the position, rotation, and tracking of the bones, but now I'm getting somewhere.

I looked at an example of a rigged mocap sequence, it wasn't the same armature/bone ratio but just by looking at the constraints I know what is needed. Like the copy location!

Twisted

I removed the 'track to' constraints and added IK solvers instead, to see what they did.

It seems to shape the body far better, but as you can see so many of the bones are twisting round. A limit rotation may be needed, but it is still not 'sticking' to the body.

Constraints on empties

Rather than weight painting my model to the armature I'm trying to use the empties with constraints.

I imported in the same 'walk.bvh' file as empties this time, and deleted the constraints I already had. (knees, eyes, legs, but kept the master), I then had to change some of the parenting to make sure it all still matched up (toe.l - foot.l - lower leg.l and for the right side).

The empties start in the middle of blender on frame 1 but when you move on in the timeline it jumps to a different place and plays the sequence from here. Then using the 'track to' constraint I made the bones in my already made armature follow the relevant empty. It made the bones jump about into an odd shape, but when they move along the timeline one can see they are doing something.

I added in some IK solvers, to see what else would happen and it seems to move the bones slightly, they are still not attaching to the empties but really pointing, I manually moved the mesh to the empties and it seemed to become more of a body shape but as soon as the empties moved away the armature and mesh seemed to fall off it. It's not following properly...

More Problems

I did manage to change the arm, but it was quite a tedious job, having to rotate the arm vertices separately. It does improve the look of the character but because of the other problems I was having it didn't seem to matter too much.

Rigging to a .bvh file (cont)

In the armature's edit mode I shaped the bones to work with the model. Surprisingly when weight painting it didn't flip out to the side, so I carried on getting all the bones to fix to the mesh the model is not created for this armature so it wouldn't fit perfectly (especially the spine as it is only one bone, four less, then what I used in my character's previous armature).

I then tested the sequence and the armature did move, but not in the way I had expected...



Firstly the arms are out at the sides - I had moved the armature into this shape but when the sequence was created the arms were by the side. I will try to change the arm shape in edit mode to see if that makes a difference.

The movement seems backwards, and very bouncy. But of course this is the first attempt so I can improve on this. I thought perhaps the armature was backwards, but upon rotating the armature, this happened:

It was like the character was melting, it was obviously something to do with where the 'mesh' label is, as it points towards that.

// It's not possible to change the frame rate on an imported mocap file, because we set that when recording.
I had to select the frames and scale down by half. This made it 450 frames, rather than 900.

Rigging to a .bvh file

When importing .bvh files they show the movement captured from the mocap, that's fine, but to get it to rig to a character is where the real challenge lies. Obviously I already have my mesh from the tutorial so I tried to use my previous 'walk' file.

I imported the file as an armature, and rotated it to stand alongside my already rigged character. I then scaled him down to get them to the same shape etc.

I changed the armature constraint to track to the new armature 'mocap_arm' and then weight painted one of the bones and this happened! It does move when I run it along the timeline, but it is placed completely wrong.


I then weight painted everything, just to check that it still formed the mesh's shape, which it did.

But of course it would not move as the motion did because it was all following the right upper arm. The black lined armature and eyes is what I used before, I've not rectified/removed this yet, which may be part of the problem?

I thought putting the armature into rest mode and changing the position and length of bones so I put the x mirror modifier on and it jumped out like this...?

Summary of Tutorial

I've learnt a lot from this tutorial, modelling a character from scratch, creating the armature, weight painting, and animating.

From here I can create the character I want (as a man, and as a 'power ranger') and get the motion capture sequence to make him move.

The next step will be to use the practice mocap sequence and see what happens...

CAT- More Facial Expressions

I found the narrow shape very difficult to make look right, perhaps because of the way I've made my model. I always thought I'd find difficulty with the way I've made the mouth. I then did a shape for the upper and lower eyelids closed respectively.

I closed the eyelids together, and combined the mouth open and narrow to create this yawn animation:

CAT - Facial Expressions

• add shape key
• with a 'basis'
• and a new shape key: open
• x-axis mirror (perfect for this) a mirror modifier would delete weight painting etc.
• snap cursor to side of head, change anchor point to rotation
• rotated from side view
• manually moved/rotated to make open mouth shape
• next I made the wide shape
• I was able to mix them in the action editer, so I could have them working at the same time.

CAT - Animation

Summary

"We split the interface into an Action Editor and a Timeline window so we can access some animation tools. We created an action (a quick wave) by moving the bones and inserting keyframes in the Action Editor."

Summary

"We created a new Action and animated a walkcycle in the Action Editor. Next, we'll mix the "Wave" action and the "Walkcycle" action together."

walkcycle

• left arm goes with right leg, vice versa.
  
• the leading hand twists the top of spine towards it

// I used the copy pose buttons, flipping the cycle position every 10 seconds.

At first the pasting did not work, but after looking in transform properties (N) at the 'roll' properties and converting to 0 it seemed to work.

ALT A - Preview animation

CTRL PG UP/DOWN - the lower action overides what's above it in NLA editor

The arm sharply jumped up when doing the wave so I used the blend tool to make the movement flow smoothly.

In the above video the eyes wobble up and down, because the eye constraint doesnt move down with the body. I spent a lot of time adjusting this by making a new action, getting the head to move towards the wave as well, but adding in lots of keyframes following the movement. It was time consuming but is well worth it:

Summary
"We used the NLA Editor to convert the actions we made into NLA strips that can be easily manipulated in the NLA Editor."

Final Rig - Screenshots

CAT - Rigging - Do's and Dont's

• head: use trackball rotation (R-R) to swivel the head around.
• eyes: move this bone around to control what the eyes are looking at. Move this bone farther away from the face to correct cross-eyes.
• make each eye track either tip or root on the "eyes" bone. Doing this makes it much easier to correct the cross eyes, and give a more natural look. simply rotate the eyes bone 90 degrees, and adjust the "head/tail" setting in each eye's Object Panel (F7).
• neck and spine bones (except spine1): Rotate individually for subtle bending of the body, or use Auto IK on the head bone for extreme bending of the spine.
• arm bones: Turn on Auto IK and move the finger2 bones for broad sweeping motions of the arms.
• master: move and rotate this bone to manipulate the entire armature. For example, using the master bone is the only way to get the whole character off the ground in a jump.
• spine1: Move this bone to move the entire upper body while the feet stay put. Very useful for walkcycles.
• knee: these bones are not used very often and are primarily used to keep the IK constraints on the legs under control. But when you need to point the knees in a direction, use these bones.
• upper_leg and lower_leg: leave these bones alone. The leg bones and IK constraints do all the work.
• leg: These are the most versatile bones. Move the leg bones to move the entire leg.
• foot: leave this bone alone, it is rotated by rotating the leg bone.
• toe: Rotate these bones to bend at the toe.

CAT - Rigging - Adjustments

Summary

"We constructed the lower body armature, added IK constraints, and weight painted it. Next we'll tweak the rig to make it easier to control."
____________________________________________________

"In this section, we'll make some final adjustments to the rig to make it easier to control. Specifically, we'll add:

• a master bone so we can move the entire character at once.
• knee-lock targets so we can control where the knees point.
• an eye target bone so we can easily change which direction the eyes are looking."

http://wiki.blender.org/index.php/Doc:Tutorials/Animation/BSoD/Character_Animation/Final_rig_adjustments

Eye tracking: Z points up, Y points backwards, so -Y points towards eye the newly created eye bone.

USEFUL TIPS
SHIFT i - IK constraint

CAT - Weight Painting

Summary

"By weight painting, we told Blender which vertices to move when we moved the bones. The character finally moves! Next, we'll build the lower body armature and do some more weight painting."

CAT - Rigging

FK - forward kinematics, rotation and 'children' follow. IK - inverse kinematics, the 'parents' follow, AUTO IK - follows all the way back to original 'grandparent' - spine. Deselect con (edit mode) to break the chain to the spine at that point.

Add modifier - armature, making sure at top, ob name = name of armature.

USEFUL TIPS

SHIFT E - symmetrically extrude
CTRL TAB - pose mode (armature)
ALT R - clear rotation
ALT G - clear location