TGJ2O

Animating using a rigged character

If you are interested in focusing more on the animation than the modeling side of 3D you can choose to do this tutorial instead of the UFo tutorial

We are going to assume you've created a complex wire-mesh character, and you've "boned" the character (that is to say you've assembled an armature for the character that resembles bones to move it properly). The next stage of animation is to use your boned character and make it move. For this exercise you're going to use this model here. I've provided it for you in this 7zip file which will save the board a bit of bandwidth.

>>>DOWNLOAD THIS <<<

You will need to use 7zip in order to unzip the package. Within the package you'll get a series of files. If you don't have 7zip, get it here. Make sure it's on the D: drive and install it.

Once the package is unzipped into a folder make sure you move it to a location in your server-space (or on the D drive).

Step 1: Turn on armatures/cameras/lights

When we open the blender file called "Flash_Barry_Allen_hero127.blend" in the folder we see a really cool model of the Flash! But we want to be able to move him. To do that we need to see his "bones".

Go to the Scene navigator in the top right and unhide everything.

You'll now notice giant blocks pushing through Flash. That's gotta hurt! These are his bones with the exception of the one main post that seems to be pushed up his nether-regions (the control bone). There are 2 clickable objects now when you click on/near Flash. Flash himself (the mesh) and the armature.

The MESH selected in Object Mode

The ARMATURE selected in Object Mode.

But sometimes a problem exists - we can't see the armature where it penetrates into the model's body. To ensure it's working properly we select the ARMATURE in object mode, look to FAR the right side at the properties editor. Notice something you haven't seen before? An Armature and a Bone tab both exist. You want to go in the armature tab and under display you want to click on X-RAY if it is unchecked. That allows us to see through the mesh at the bones.

Your model should now look like this:

Step 2: Pose-Mode

Some theory - because somebody's already parented the body to the bones inside of them, when the bones are moved, the mesh nearby moves. This is a part of modeling known as "Weight Painting". While that's beyond the scope of this course, if you wanted to adjust the location of where an armature's influence is, you'd change the parts of the mesh that would be affected. For example, below is an example of the mesh-area that is impacted by the bone underneath it. Areas close to red are areas of more influence.

The collar-bone will move/deform the area above it to an extent. Yellow is the "strongest" influence above. Notice the absence of red or STRONG influence.

The mid-chest bone will STRONGLY impact the mesh nearby (strong in red, weak in cool blues)

We are going to only be working in POSE MODE and translate/rotate ONLY various bones to give our model the appearance of walking. To enter pose mode you select only the armature, then either press CTRL+TAB or go down the the menu at the bottom of the 3D window and switch the selector to POSE MODE.

Step 3: Switch the rotation center

By default, the rotation center in this model is the origin. We need to change this. Why you ask? Go into FRONT ORTHO view (1 on your keypad). In pose-mode select the right collar-bone. The author of the model didn't call bones by their proper names or heirarchy (a professional boo-boo). Instead his armature name for the model's right shoulder is VisualSceneNode41 (likely a default name).

When you attempt to rotate this bone (R) around the Y axis, the whole shoulder deforms weird and pulls the mesh from the body. This is because our rotation point for that bone is set to the 3D cursor, which is at the origin still. We want to switch the rotation point to something OTHER than 3D cursor (in this case BOUNDING BOX is just fine - it's at the bottom of the screen next to the shading menu).

Now when you rotate (R) around Y axis (y) the shoulder deforms properly. Notice you can't really rotate it too far before it looks silly? This is because humans can't do that either.

Play around with various bones in the body, rotating them around their various axes. Get used to what the body can do. In our next step we're going to make Flash walk.

Step 4: Walk cycle - setting up for poses

In modern animation people use what is knows as Inverse Kinematics (IK). IK allows us to grab controlling bones for the body and move them to allow the rest of the body to move easily. We are only partly doing that sadly (legs only, but typically it's done with the arms and torso as well). Because this is a model from taken from the internet we don't have control over what bones have been placed where. I edited the leg structure so that IK works for them, but the hands have been "boned" oddly, thus we're going to have to work with what we have.

Next we are going to create a library of poses, then allow the animation library to access them to create a walk cycle. Below is an example of how easy life can be using IK. If you want to know more about IK, here's a (not so) quick and dirty tutorial

So we're going to create a walk cycle manually using this POSE LIBRARY. First things first, we're going to rotate all the bones along X/Y/Z so Flash looks normal standing there. It's easiest to do this with what is called QUAD VIEW (CTRL+ALT+Q, or VIEW>Toggle Quad View). Arrange Flash so he looks comfortable

You may want to change the bone view to STICK instead of OCTAHEDRAL at this point to make viewing bones for poses easier. Finally, we want to open up the pose library section of the properties manager and create a new library called Flash.Walk

We're now ready to start entering poses.

Step 5: Walk Cycle

We're going to drag our left foot control bone (the thing leaving the bottom of his foot) and move it a bit forward, we're also going to cant the body forward and swing the arms according to how somebody walks (leading leg means trailing arm). Crucially, we need to select all the bones and then going to press the + symbol (Add Current Pose to library) in the Flash.Walk library of poses. This will enter the pose in the library. Rename this pose to Flash.Walk.1.

We are going to insert this as a keyframe in our animation. You are to navigate to frame 1, with all bones selected press the i key, and insert a WHOLE CHARACTER frame. End your animation at frame 24 (1 second of motion). Now go to frame 48 and hit 'i' to insert whole character again. This ensures that the first and last pose are the same so our "loop" works nicely. Before we do anything else, on frame 1 select all the bones (A key) and press CTRL+C (copy, or alternatively, POSE>Copy Pose from the menu).

Next we're going to go to frame 24 (the midpoint of our stride). At this point our bones should be mirror images of each other, so we're going to SHIFT+CONTROL+V (or alternatively POSE>PASTE X-FLIPPED POSE). Our legs will be nice mirror images of where they were, but the arms go all wonky. We need to fix the arms into their new position. As well, any other adjusted bones may need to be re-adjusted now. Do so. Once you're happy with a "mid-stride" pose insert it into our Pose Library at the right. Call it Flash.Walk.2

Press play on the animation. Fantastic you think - but notice how the character is "gliding". We want him to walk normally (i.e. bounce). As such, we're going to go to frame 12, and grab the main control-bone (the one sticking up his keister, called VisualSceneNode1) and translate it up the Z axis just a little bit (less is more is the old adage, small changes make things far more believable than large changes). If you like the change enter the pose in the library as Flash.Walk.3

Again, copy all his bones and change to frame 36 and select POSE>PASTE X-FLIPPED POSE. Add that post into the library as Flash.Walk.4 We now have a bounce in his step at frames 12 and 36 and 'maximum stride' in frames 1 and 48

This is good. Pressing play makes it look like Flash is actually walking.

Step 6: Make it interesting

Fine. We have a walk cycle. What would make it interesting is if we were able to continue on and have, say, a background and make it look like Flash is actually walking around. Thanks to our Pose Library, we can. We can copy those basic poses, and apply them every 12 frames (1/2 of a second). First we're going to >>>THIS PICTURE HERE<<<. Then we're going to go back into OBJECT MODE.

[souce:http://sciencelakes.com/data_images/out/19/8829938-wheat-field-background.jpg]]

Once in OBJECT MODE turn OFF the Automatic Keyframing for animation purposes.

Switch to an overhead view and put the 3D cursor along the Y axis off behind our friend Flash (I have mine at y=7)

Now, press SHIFT+A and insert an empty image

In the Properties Editor on the right, open the Wheat Field Background. You'll see a tiny copy of the wheat field from overhead.

Now we're going to scale it bigger and rotate on the X axis it so it is behind Flash.

We're now going to go back to quad-view which is CTRL+ALT+Q. This will help us position Flash to make a more realistic walk-cycle against the background. Set up the distance between the Wheat Field image, Flash and the camera such that AT FRAME 1 the camera view looks like this.

Notice in OBJECT MODE I have the armature selected to move where Flash is. Once you're happy with how far away he is, turn on the KEYFRAME INSERTION button (Red circle) to start animation. Press i to insert a LOCROTSCALE keyframe. Turn OFF keyframe animation now switch to frame 48. Reposition Flash and the camera such that your final picture looks like this. turn on KEYFRAME INSERTION and insert a LOCROTSCALE for the armature placement. Notice Flash is still going through his poses even though the armature is moving?

The danger of not actually modeling our ground is that we have to be particularly careful about making it look like he's walking at a realistic speed. Even here it's easy to make his step "slide" while he switches feet.

Step 7: One extra thing

Ok, that's cool and all, but what about making it even more believable? Aside from lighting (which you can do if you want, but the purpose here is simply to introduce poses), the other things that could be done to increase believability would be a head turn, and a longer walk. We're only going to introduce a head turn as if Flash was looking at something to the side.

Go into POSE MODE. Turn on KEYFRAME INSERTION and grab Flash's neckbone. Go to FRAME 12 and turn Flash's neck (rotate) so that he's looking off to the side. Press i to insert a LOCROTSCALE keyframe. Now, with ONLY the neckbone selected, press CTRL+C (copy). Go to FRAME 22 and paste (CTRL+V). Notice how Flash's head goes to the same rotation? Press i to insert a LOCROTSCALE keyframe. Play your cycle.

Great - we're done! Only when we go to export the animation (using the same type of render settings as in the last assignment H.264 etc..), the background isn't showing up is it?

Step 8: Replacing empty with a textured surface

What we need to do next is create a surface with that exact same texture on it (picture) with that exact same size. To find out the size of our empty is easy. We are going to click on the protractor/ruler button

Let's drag the protractor across the bottom of the empty. Your value may be different, by my empty is 46.3 units across. My vertical value is 27.8 units.

So what I need to do is ADD>MESH>PLANE and on the right side with N key (the property inspector) open, put in your X and Y values for the plane. You will probably have to rotate the plane 90 degrees to make it line up with your empty. I also had to increase the size of Y from 27.8 to 28.972 in order for it to cover it properly. When viewed from the front, side and top the plane you made should line up with the empty that has the drawing on it. Quad View is helpful for that.

Notice how in the TOP, FRONT and RIGHT views the highlighted PLANE that was created matches the empty that has the picture of the wheat field on it.

Now all that remains to do is texture the surface of the plane just like how we put the starry sky on the dome in our last assignment. We'll make sure that the PLANE is selected and go to MATERIALS on the right side properties panel. Create a new material slot for the plane (top right +), then create a new material IN that slot (the + sign farther below). Now to go textures.

So, what we're going to do is make a new world texture (the blue circle to the left of the one displayed below) called BACKGROUND. Now click on the next circle that is TYPE OF TEXTURE and choose source as IMAGE and go down to the image-select dropdown. Navigate to your WheatField picture and select it.

Finally, up in the Scene navigator at the top right you'll notice that you can hide the EMPTY and with only the Plane (I've renamed mine to Plane.WheatField.background) turned on you can still see our wheat field.

Setup up the render for export now using the H264 codec as in the UFO tutorial.