Art 484: Advanced 3D Animation Neal McDonald

mcdo@umbc.edu

Lecture 1, Feb 2

Setting Projects

•  Make a directory on D drive w/ your name •  In Maya, File=>Project=>Set… •  Project directories are where your files go.

– Maya scene files: .ma, .mb – Files you use in your animations: texture files – Files that Maya makes: image files, others

•  Default project setting fills your student account! So Set your project!

6 Steps for making an Animation

1.  Planning 2.  Modeling 3.  Rigging 4.  Animating 5.  Materials and Lighting 6.  Rendering and Post-Production

1. Planning

•  Making a CG film is of comparable complexity to building a skyscraper.

•  Business management is crucial, or you waste all your money.

•  Storyboards give camera angles, shot contents, and intention

•  Model plans give specifics •  Art direction coordinates all content.

2. Modeling

•  Computer Models are surfaces made by connecting vertices– points.

•  They are what you see in the animation. •  No physicality: no weight, no rigidity, no

impermeability. •  How they reflect light is determined by

their shaders (in Maya, Materials).

3. Rigging

•  Rigging is the building of a user interface for a model that allows an animator to move the model in specific ways.

•  The interface should be easy to use. •  Not all movements are ever allowed

– Smiling is different from changing your face to look like your Dad’s.

4. Animating

•  Animation (in this context) is the addition of motion to the models.

•  Many kinds of animation in Maya: keyframe, simulation, procedural.

•  Don’t forget to animate cameras and lights!

5. Materials and Lighting

•  Materials define how light is reflected off an object. – Color – Shininess – Texture Mapping uses images (e.g.

photographs) to set an object’s color. •  Lighting puts simulated light sources,

emitting simulated light, into a scene.

6. Rendering and Post

•  Rendering is the conversion of a 3D scene into a 2D image.

•  Done with a renderer– a separate program •  Uses an imaginary camera to sample the

imaginary light you put in in step 5 •  Post-Production: operations on 2D images

– All the things that After Effects can do. – Conversion to movie files.

6 Steps for making an Animation

1.  Planning 2.  Modeling 3.  Rigging 4.  Animating 5.  Materials and Lighting 6.  Rendering and Post-Production

•  Questions? Let’s make an animation, then!

1. The Plan

•  Make a bouncing ball, set it on fire. •  The model will be the standard sphere. •  The set will be a big, flattened cube. •  Make the ball bounce from one end to the

other. •  Don’t animate the camera. •  Use the default light set and material.

Maya Review

•  Starting up •  Moving camera, switching views. •  Recovering UI windows •  Making spheres, cubes, etc. •  Translate, Rotate, Scale, Duplicate •  Projects

2. Model

•  Make a ball and a cube. •  Flatten the cube and make it big. Move the ball

to one end-- use "w", "e", and "r"!

3&4. Rig and Animate

•  No rig. •  We will make a Keyframe Animation •  Keyframe animations are a set of poses that are

interpolated.

•  3 Steps to make a keyframe: –  Set the frame number by dragging in the timeline. –  Set the scene to be how you want it –  Press the ‘s’ key.

Keyframe set! Make sure that your time slider is on frame one, then press ‘s’.

The red line that appears in the timeline indicates that you have set a keyframe.

Repeat the process: Slide to the last frame, Move the sphere to the other side of the table, Press ‘s’.

Troubleshooting

•  Is the sphere selected when you press ‘s’? If it’s not, Maya doesn’t know what object the keyframe should move.

•  Is caps-lock on? If it is, you’re not pressing ‘s’.

•  Did you move the ball before you moved the time slider? If you did, the ball moves back when you move the slider.

Further Animation

•  Add a keyframe at frame 12 that moves the ball up

•  Change the scale at frames 1, 12 and 24, so that the ball is fat when it hits the ground and thin at the top of the arc

•  Make the ball bounce 3 times by adding keyframes at 4,8,16 and 20.

•  Shelf:dynamics=>

5: Materials and Lighting

•  We'll use all defaults-- this time.

6. Rendering

•  Use the clapboard button to make a single image.

•  We need Maya to make many images, not just one– bring up the “Render Settings” dialogue.

Render Settings for Animations

All set? Batch Render

Bring up the script editor to monitor progress

Great! Where?

There should now be 24 frames in your project directory.

View in FCheck or AfterEffects.

Axes and Rotations

•  Run Maya, find the axes in the lower-left corner.

•  Use the “right hand rule” to connect the red X to the red circle.

Theory Moment: Animation

•  Animation = Physics + Acting + Puppetry –  We’ll model this on Cartesian Mind-Body dualism.

•  Physics is all the stuff that happens because things are made of matter: collisions, heaviness, stuff sticking together, falling over, and so on.

•  Acting is the depiction of consciousness: emotions, second thoughts, memories, motivations.

•  Puppetry is depicting these things through an interface.

Physics: Newton’s 3 Guidelines of Motion

•  Inertia –  Things not moving tend to not move –  Things in motion tend to keep going

•  F = ma – force = mass times acceleration –  Acceleration = rate of change of velocity –  Velocity = rate of change of position –  Force is exerted in a direction, on the object at some

point. –  The heavier the thing, the harder it is to move it.

•  Every action has an equal and opposite reaction –  I push you, your weight pushes back.

Acting

•  Acting depicts what the character is thinking.

•  Acting = Breathing + Focus + Backstory + •  Focus is, pretty much, eye direction. •  Breathing is all the motion that happens

because a character is alive. •  Backstory gives motivations, rationales,

external events, ...

NURBS curves •  A way of taking four points and returning a smooth curve

between the first and last. •  Two end points, two tangent points •  By moving the end points, you change where the lines

start and stop; tangents change direction •  Maya uses NURBS curves to make surfaces and

animation curves

Linked NURBS curves

•  Match up end points, and put the tangent points in a line, and you get a longer, smooth curve

•  Each section can only change directions once, but combined sections can change lots

The Graph Editor

•  Allows you to edit the animation curves by moving end and tangent points – which gives you total control over your

animations – Keyframing like we did last time only gets you

so far... •  Main Menu=>Window=>Animation Editors=>

Graph Editor

Reopen the bouncing ball

Fixing bounce behavior with graph editor

Before we go on

•  Project set? •  Tool tips!

Imagine a Baby's head

•  Soft bouncing slows down – Gentle! good for babies –  rounded tangents-> no fast speed changes

•  Hard bouncing does not slow down – Felony for babies, good for golf balls – pointy tangents -> abrupt changes

Look at the curves

•  Two balls, one with a hard bounce, the other with a baby-head bounce

•  Look at the lines in the graph editor –  (w/ GE open, select a ball)

The Graph Editor

•  A = "Frame All" button-- centers •  B = the names of the animation curves

attached to the object

•  Use translate and scale as in 3D

More Graph Editor

•  B= a selected curve-- only it is drawn •  C= a point with tangents •  D= a frame number •  E's= other keyframes

•  Note blue line

Moving keys

•  Look at the 4 keys in the top left •  Leftmost = "move nearest key" tool •  Left-click on a key to select it •  Middle-click NEAR that key to move it

– Not normal mouse behavior! Hate that.

Seeing Tangents

•  The yellow dot is a selected key •  Note frame# and key values •  The brown line is two tangents •  The tangents are tied •  To rotate the tangents,

–  left-click on the key –  left- click on the tangent dot – middle-click and drag

Breaking tangents

•  The tangent points start out linked – by the interface – when you move one, Maya moves the other

Unifying tangents

•  After you unlink a pair of tangent points, you can re-link them

•  Moving one moves the other again

Adding keyframes

•  Left middle: Insert Keys: preserves curve's shape

•  Right middle: Add keys: puts the key down

•  Remember: – Middle Mouse! – Left does nothing

Dragging and scaling many keys

•  Use the timeline, not the graph editor •  Shift-drag on the time line-- turns red •  Arrows appear; drag on them to scale and

translate

More Tangent Types

•  Linear Tangents – puts all the points on a line

•  Step tangents •  Violates our 4-point ideas, but, ... ok...

pre-infinity and post-infinity

•  gives you easy looping •  sometimes they save you, sometimes not

•  The Trax Editor is the next step up, but we won't get to that in this class