Cinema 4D Handbook: Chapter 8

20Oct11

Hello all. It has been a painfully busy couple of weeks. Which is why I’m just now getting around to chapter 8. I also wanted to go through the chapter twice, just to make sure I got it all. So, without further ado, here’s my round-up.

Chapter 8: Character Setup

“Character animation is the pinnacle of the 3D artist.” Creating a character that walks, talks, and shows emotion is a combination of every part of 3D modelling. This chapter has 4 long tutorials: Morphing, Joints and Rigging, Controllers and Visual Selectors, and Skins and Weights. All of which are important to a successful animation.

Tutorial 8.1: Morphing

Cinema 4D uses a program called MOCCA 3, and the tool Morph. It works best with facial expressions. When working with Morph, you need to think of each action you want the face to make, and then you add a Morph Target to each separate action. You start by adding a Morph Tag to a property. *NOTE: This is a very long tutorial with a lot of steps that have a lot of detail. I will try my best not to be too wordy with it.

To Add a Morph Tag:
1) Select the object, then Right-Click on it and choose Character Tags> Morph.
2) Make a selection of the points you want the tag attached to. *NOTE: The book recommends making selection tags for individual groups.
3) Use the Move and Selection Tools to adjust the points.
4) In the Objects Manager, select the Morph Tag.
5) In the Tag Properties use the Strength Slider to show the movement in your points.

If you are working on morphing something like the eyes, then it helps to change the axis of the morph. By adding a Rotational Morph you can create realistic spherical shapes.
To Create a Rotational Morph:
1) Select the Morph Tag of the morph you want to rotate.
2) In the Mode section of the Attributes Manager, change Relative to Rotational.
3) Zoom into the area and use the Points Tool to create a point; Shift+Click to create a second point at an opposite corner.
4) In the Attributes Manager for the Morph Tag, click on Set Rotation from Points.

Driver vs. Driven

One of the most important thing to do when setting up a character is to set the Driver and Driven attributes. When you work with multiple morphs, then you can set specific actions to effect other actions. EX: when the eye opens, the eyebrow also moves.
To Set Driver and Driven:
1)  In the Tag Properties of a Morph Tag, Right+Click then choose Animation> Set Driver.
2) Right+Click on a second tag and choose Animation> Set Driven.

Creating a Driver/Driven relationship adds a Null Object to the Object Manager. If you delete the null, then the link between the objects will be broken.

Tutorial 8.2: Joints and Rigging

A model can’t move without rigging. Think of it as the skeleton of your character. You create bones, joints, give them weight, and putting it all together creates a character that moves. “Rigging isn’t for the faint of heart, and you will need to remain patient and be willing to trek out on your own if things don’t work.” There is a lot of guess and check with rigging. When you rig, be sure to use the Save Incremental function. This will let you revert to a previous save if things go wrong.

The Joint Tool
The Joint Tool allows you to make the structure that is your primary skeleton. “You first do the joints for the spine, then the neck/ head, and finish with the arms and legs.” After you make a series of joints, you can combine, split, and move both individual joints and joint groups. You want to mimic real life anatomy in the skeletal system.
Joint Tool Options:
Root Null upon creation, your joint chain would be parented to a null object.
IK ChainIK Chains are controllers which allow for enhanced control of individual joints.
Align Axis–  this will make sure that your joint’s axes will all be related (all pointed the same way).

Creating Joints for the Root Spine:
1) Select the Joint Tool (from the Character Menu) then create joint starting from the hip, running to the shoulder. *NOTE: to draw joint using the Joint Tool, you must hold down the Control key when you click.
2) Click on the Move Tool to end the Joint Tool session. This will create an IK Spline Tag. *NOTE: When you create points, be sure to use multiple Viewports to ensure that your splines are aligning correctly.

IK Spline Tags
IK Spline Tags allow you to make adjustments to the newly created IK Spline. Controlling the arc is really similar to controlling a bezier curve in Adobe. to control an IK Spline tag you also have to add IK Spline Handles.
To Create Handles:
1) Click on the “Handles” button in the Attributes Manager for the IK Spline Tag.
2) Click the “Add” button to add a new Index Indicator and input your number of joints.
3) Click “Create” to make a new Null Object. Rename the null.

In order to more efficiently work with your IK Spline, you need to change it to a B-Spline. When you created it, it defaulted to a Bezier Spline, but you have to switch to Points mode to edit the handles. A B-Spline will allow you to edit the handles without going into Points mode.
To Change the Spline Type:
1) Select the spline in the Objects Manager.
2) In the Attributes Manager change the “Type” to B-Spline.

Occasionally, when you create a spline, the axis of the joints will become inverted. This makes rigging very difficult.
To Re-Align the Joints:
1) Select the inverted joint.
2) Choose the Align command. Character> Align

IK Chains
“One of the most important aspects of any rig is the IK Handle that you’ll use to affect the arms and legs. Once the splines for the an arm or leg has been created, you can create and IK Chain. IK Chains create a link between two joints for movement. When you create an IK Chain, you also create a new Goal. Goals are controllers that operate the newly created IK Chain.
To Create and IK Chain:
1) Select one joint in the Objects Manager. (IE: the joint that creates the shoulder).
2) Control+Click on a second joint. *NOTE: In order to create a working chain,  the two points must be separated by at least one other joint.
3) Choose the IK Chain command. Character> IK Chain

Pole Vectors
One problem that may come up with your rigging is the direction that the elbows and knees are pointing. To control this, you create a Pole Vector. Pole Vectors are points in the IK Tag that give you access to the joint.
To Add a Pole:
1) Select the IK Tag of the shoulder joint.
2) In the Tag Properties of the Attributes Manager, click on “Add Pole.”
3) Drag and drop the new pole out from the shoulder joint’s hierarchy in the Objects Manager.
4) In the top view, move the pole so that it is behind the elbow.

The Mirror Tool
When you create a human or animal model you model half of it, then mirror the second half. The same is true when rigging. You only have to create a rig for one side, then you can use the Mirror Tool to duplicate the other half.
To Use the Mirror Tool to Create Rigging:
1) Select either the arm or leg that you want to duplicate.
2) Select the Mirror Tool. Character> Mirror Tool
3) In the “Options” of the Attribute Manager, change the Plane to “World YZ,” change Origin to “World.”
4) In the Replace field type “L_” and in the With field type “R_.”
5) Click on “Mirror.”

Completing the Skeleton
Once you have finished creating all of the armature of your model, it is time to piece them all together so that they can interact with each other. EX: when you move the spine, the arms will be effected as well. Combining chains is all about the parental hierarchy. The spine is the ultimate root, then everything else spurs off from there.
To Combine Joint Chains:
1) In the Objects Manager, Drag and Drop your neck and arm chains onto the top end of the spine.
2) Then Drag and Drop the leg chains onto the bottom end of the spine.

Tutorial 8.3: Controllers and Visual Selector

Once you have a completed armature you can move on to creating controllers. Controllers are Null Objects that have been linked to various features and control the way those features move and act. Just like with the armature, you can mirror the controllers after they’ve been created.

Arm and Leg Control
Creating realistic movement for the arm would be very difficult without Controllers. Instead, we can create a Controller and link it to a Goal and a Pole to create the movement.
To Create the Arm Controller:
1) Create a Null Object.
2) Select the Move Tool then enable 3D Snapping and Axis Snapping.
3) Place the null over the shoulder joint and it will snap to it.
4) Link the arm’s Goal and Pole to the null.

 

Visual Selector
You can create controllers to effect just about any physical trait on a rig. The controllers make it so you don’t have to go to the Objects Manager to animate. The Visual Selector is a pop-out window that shows you all your controllers.
To Set Up the Visual Selector:
1) Create a Null Object and name it “Visual Selector.”
2) Right+Click on the null and choose Character Tags> Visual Selector
3) From the Objects Manager, drag a controller to the Visual Selector window.
4) Drop it over the corresponding body part.
5) Use the menu to set the controller’s action.

Tutorial 8.4: Skins and Weights

“For you to get the skeleton and controllers to move the character, you must link a Skin Object from the Character menu to the model’s geometry.” Then to make it realistic, you have to add a Weight Tag. “Weighting, sometimes called Paint Weighting, is where you tell the joints how much influence they should have over certain vertices.”

Skins
Skins are what tell the geometry to be subject to joints and controllers. By linking the skeleton to your skin, you can create movement.
To Create the Skin:
1) Select the root joint of the joint group.
2) In the Objects Manager choose Edit> Select Children.Then Control+Click the model. This will select all the joints of your skeleton.
3) Use Bind to create a Skin Object. Character> Bind *NOTE: This also creates a Weight Tag.

Weight Tags and Weight Tool
“The Weight Tag is the link between the joints and the geometry.” The Weight Tag has four buttons in the Attributes Manager: Auto Weights, Clear Weights, Reset Pose, and Set Pose. When you use the Bind command, C4D defaults to Auto Weights. The Weight Tool allows you to paint tension onto joints. This will make your model more realistic. The Weight Tool is found in the Character Menu. There are some options to be aware of, but the basic way to use the tool is simply to paint over joints. The more you paint, the more tension you create.






Once again, I apologize for this taking so long to get out. But the rest of the chapter are pretty short, and I should be done posting them by the end of next week. Like I said, there has been a lot going on, and I have plenty of gear reviews and projects to show you. Thanks for reading.

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