Let's do a little animation on an articulated wooden man. Before we begin, make sure to organize him hierarchically so he can be moved easily. Now, let's rotate him so he is facing the mirror.
Now we can use Forward Kinematics to rotate the biceps of the wooden man to his sides. Now, record a keyframe for the shoulders to give your computer a starting point. Then move the current time marker to about 30 frames and repose the dummy using FK by moving the biceps, then the forearm, and finally the hand into a buff posing position, and then record a keyframe. Repeat the process for the other arm, record a keyframe, and then refine the head and neck so the dummy is looking at the mirror.
We can further refine this particular pose by moving the current time marker back to 0 frames and recording a keyframe for the chest. Then move the current time marker back to 30 frames and rotate the chest forward and the head up. Record a keyframe. We will use IK to animate the lower body. First, be sure to create an effector or a null object that will nail down the ankles of the character. Create a goal object, or IK target, at the base of each heel.
Then, assign each leg to point toward its respective goal or target. Now, record a keyframe for the target or goal at 0 frames. Move the current time marker to 15 frames, then move the target into the air as the first part of a step forward, and watch the leg follow into position. Record a keyframe. Next, move the current time marker to 30 frames and place the target/goal on the floor again a little in front of the original position.
Record a keyframe and then adjust the angle on the back foot to show that there is no weight on it since all the weight has shifted to the front foot. The motion of the dummy making a pose in front of the mirror is complete. Now that we have spent all this time looking at IK and FK chains and how they work, let's take a look at a couple of ways that bones can be used besides chains. When a bone is attached to a group of polygons, all those polygons are affected no matter how the bone is altered.
Most IK and FK functions are focused on the idea of bone rotation. However, bones can also be resized, and the polygons attached will resize as well. Figure 10.18 is a simple sphere with one bone set in the middle. This may seem an overly simple example; after all, this sphere could simply be resized without the use of bones.
However, with complex models, one bone can control a multitude of objects and shapes even if they are not grouped. Bones can also be created and set up in nonchain formats. These two bones are set up in tangent to the oil tank shape, but still are just as effective.
Comparison Bushnell Medalist Rangefinder Cheep Acetyl L Carnitine Alpha Lipoic Acid Ozark Trail Hiking Boots Cheap
No comments:
Post a Comment