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Goals and Objectives: This booklet was designed to empower our workforce with more knowledge in 3D. We have noticed that rigging is one of the most hated aspects about the 3D world and not a lot of people know how to do it, that is why through this booklet we want to show them the easiest way possible to learn how it can be done.

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What is Character Rigging? In 3d animation, character rigging means the process of preparing the character for animation. The idea is to use special helper objects and modifiers to prepare a set of tools that make the animating process as easy as possible.

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Table of Contents Bone Tool

1

Drawing the bones Adding Skin Connecting bones to the skin

3 5 7

Setting the weights for each bone

9

Weights cont’d Create the controllers Finished Rig Glossary

11 13 15 17

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Preview of the 3d human model that has been used in this tutorial

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Step 1:

Fig. #1 1


Bone Tool First, select the Front view port. Then you will go into the systems menu, under helpers, you will select the Bone Tool. (Refer to Fig. #1 on the left)

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Step 2:

Fig. #2 3


Drawing the Bones Next, simply draw the bones where you need them, and remember; all bones must lead back to the center, which is the main controller, and for the limb bones, go to the IK HI Solver dropdown list, and select IK LimbSolver. (Refer to Fig. #2 on the left)

4 Full bone set


Step 3:

Fig. #3 5


Adding Skin This is the easiest step to follow, no matter what. First, select the model. Then, go to the modifiers drop-down list and select “Skin.� (Refer to Fig. #3 on the left)

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Step 4:

Fig. #4 7


Connecting bones to the skin After you’ve done this, you can select the bones you want to add by scrolling down in the modifiers parameter box. You will see an empty box, with “Add Bones” above it, click this, and select all the bones. (Refer to Fig. #4 on the left)

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Step 5:

Fig. #5 9


Setting the weights for each bone This step is easy, but can take a long time, especially if you placed the bones wrong, or missed some of them when you were adding them to the Skin. Under the skin modifier, you should see a checkbox that says “Edit Vertices.� Check it, it will make your job easier. Down near the bottom of the list, you will see a wrench-shaped button. Click this, and it will bring up your weight tool.. (Refer to Fig. #5 on the left)

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Step 6:

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Fig. #6


Weights cont’d Going for each bone, you must select each vertex and choose the weight the bone will have for it. I suggest setting them going outward from one to zero each row, ringing outwards from the center of the bone. You must do this for each and every bone, make sure each and every vertex has the correct controller bones and weights, otherwise, your mesh may not deform the way you want it too. You can also choose to paint the weights, if you’re looking to save a little time, but it does not offer the kind of exactness needed for still life objects and the like, but may be quite effective for organic objects. (Refer to Fig. #6 on the left)

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Step 7:

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Fig. #7


Create the Controllers This is the final step. All you need to do is create boxes and circles around the key parts of the bone system to control the bone rig. Then, you link the key bones to these controllers, hide the bones, and you’re ready to animate! (Refer to Fig. #7 on the left)

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Step 8:

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Fig. #8


Finished Rig

Fig. #9

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Glossary 3D Three-dimensional. Descriptive of a region of space that has width, height and depth. Bone A rigid object analogous to a real bone, placed inside the ‘skeleton’ of a character during the process of rigging it for animation. When a bone is moved, it acts upon the mesh of the character model, deforming it. Character Animation A sub-area of animation that deals with the simulation of the varied movements of living creatures. Usually, before a character model can be animated, it must be set up with an underlying skeleton, constraints and controllers: this process is known as rigging.

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Constrain To restrict the motion of an object to one or two planes, or to a certain range of values within a plane, in order to simplify the process of animation. Constraints are commonly imposed on joints within a skeleton during the process of rigging a character for animation, in order to prevent that character from performing actions that would be physically impossible. Forward Kinematics Often abbreviated to FK, Forward Kinematics is a character animation technique for controlling the motion of the bones in a chain – for example, a limb – in which rotations propagate from bone to bone towards the free end of the chain (in the case of a limb, towards the hand or foot).

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cont... Inverse Kinematics Often abbreviated to IK, Inverse Kinematics is a character animation technique in which the end bone of a chain - for example, a limb - is assigned a goal object. When the goal object moves, the bone moves with it, dragging the rest of the chain behind it. The movement propagates from the free end of the chain towards the fixed point: the reverse of Forward Kinematics. Joints Points of articulation between the bones in a character rig. Keyframe An image, or set of attributes for a 3D scene, used as a reference point in animation. The artist usually sets up keyframes manually at significant points in the action, and the computer calculates the inbetween values automatically. 19


Model Used as a verb, to model means to build a 3D object. Used as a noun, it means the 3D object created as the end product of the modelling process. A variety of different methods are used in 3D modelling, including polygonal, NURBS, Sub-D and metaball techniques. Rendering The process of converting the 3D data stored in a software package into the two-dimensional image ‘seen’ by the camera within the scene. Rendering brings together the scene geometry, Z-depth, surface properties, lighting set-up and rendering method to create a finished frame. Rendering comes in two forms: Display or Hardware rendering, used to display the scene on-screen in the software package’s viewports; and the more processorintensive Final-quality or Software rendering, which generates an image for output, and takes account of properties that Display rendering overlooks, such as shadows, reflections and post-process effects. 20


Rigging The process of preparing a character model for animation, including setting up an underlying skeleton, complete with constraints, controllers and kinematic systems, and linking it to the mesh of the character model. Scene A set of 3D objects, including the models themselves and the lights and camera that will be used when rendering them out. Skinning The process of binding the surface of a model to the underlying skeleton during character rigging. Skeleton An underlying network of bones used to define and control the motion of a model during character animation. Moving a bone causes the mesh of the model to move and deform. 21


cont... Symmetry A modelling option in which any changes made to the model are duplicated across an axis of reflectional symmetry. This makes it possible to create complex symmetrical objects, such as a human or animal head, without having to work directly on more than one half of the model. Walk Cycle A short sequence of animation containing the keyframes necessary to make a bipedal character take two consecutive steps. The sequence may then be repeated over and over again to animate the character walking forward. Walk cycles may be modified in many subtle ways to suggest information about a character’s age, gender, emotional state or personality.

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How to rig a human character