Digital Video Special Effects

9/19/2006Instructor: Wen-Hung Liao, Ph.D.

Administrative Information

E-mail: whliao@cs.nccu.edu.tw Office: 大仁樓三樓 Office hours: TBA Course web page: http://

www.cs.nccu.edu.tw/~whliao/DVFX/ Textbook: none Guest instructor: Mr. 駱俊嘉 Software tool: Adobe After Effects

Background

Top movies: All-Time Worldwide Box Office All-Time US

Forrest Gump Screen Shots

Background

Digital video special effects (DFX) have revolutionized media industry.

Artists can create visually stunning DFX. DFX is used in nearly every production. DFX companies have appeared:

Industrial Light & Magic (US) Realviz (US) Rhythm & Hues (US) Weta Digital (New Zealand) and many more

Digital Special Effects

What makes DFX interesting and captivating? DFVX are used when real life shoots are difficult,

dangerous, too expensive, or impossible. DVFX must look realistic and believable. DVFX must blend into the real scene

seamlessly. A good DFX is one that the viewers do not

realize it is there.

Digital Special Effects

DFX are created using DFX elements: Real visual elements:

video or film footage of real scenes, actors, objects, motions, actions, natural phenomena, etc.

CGI (computer-generated imagery) elements: Computer Graphics (CG) scenes, actors, objects,

motions, actions, natural phenomena, etc. Audio elements:

dialogue, sound effects, music, etc.

Digital Special Effects

Difference between DFX and computer animation: Computer animation involves only CGI elements. DFX involves real visual elements, and

sometimes CGI elements also. Most DFXs require the CGI elements to look realistic.

Creation of DFX is part of the media production process.

Production Process

Media production can be organized into 3 stages:

1. Preproduction

2. Production

3. Postproduction These three stages often overlap. Look for some bonus footages included in a

DVD.

Preproduction

Project proposal: summary used to sell project

Premise: concise statement of story Synopsis: short description of basic story line Scripts: production guides on paper Storyboard: graphic visualization of shot

sequence. Schedule, budget, etc.

Production

Conceptual design: artistic concepts of visual elements in pencil and paper and small sculptures

Set construction: construct set, miniatures, etc. set up stage, cameras, lighting, rigs.

Document the set: for use in creating special effects Props construction: construct props, prosthetics, etc. Costume design: design and make costumes Rehearsal: rehearse dialogues, moves, etc. Live shoot: shoot actors, scenes, etc. Create CG models: sculpt models and do 3D scans CG animation: 3D motion capture, animate CG

models

Postproduction

Compositing: compose various DFX elements together

Sound recording: record sound effects, music, etc.

Music scoring: compose and score music Sound mixing: mixing dialogue, sound

effects, music, etc. Editing: visual and audio editing, film editing

Storyboard

Storyboard is a graphical visualization of shot sequence.

A shot is basically from when you press record, to when you stop recording.

Storyboard allows filmmaker to visualize and refine ideas.

Serve to communicate ideas to production team. Each panel of a storyboard depicts a scene, type of

camera shot (angle), possible camera move, etc.

More Information

More details about camera shot:

www.mediacollege.com/video/shots www.cssd.ab.ca/tech/digvid/cameraangles.html

camera move: www.siggraph.org/education/materials/HyperGrap

h/animation/cameras/traditional_film_camera_techniqu.htm#Camera%20moves

Storyboard: Examples

Can be elaborate or simple

Animatics

Animatic contains a sequence of storyboard images, narrative,

dialogue, sound effects, music, etc. Give director a good sense of how the movie

will look.

Pre-visualization

Storyboard contains only still pictures, lacking dynamic information such as shot duration, camera move, etc.

Pre-visualization (or pre-viz) shows crude CG animation.

Give director a better sense of camera shots and moves.

Let director explore various shot possibilities before actual production.

Documenting the Set

For constructing 3D CG models for matching camera motion and lighting conditions.

Thoroughly document the set before shooting. First priority: reference points

Used for tracking and match move. Should be visually distinct from surrounding. Should look the same throughout camera moves. Examples: staircase, door, corner, etc. Can also make your own reference point using a ping-pong

ball painted in Day-Glo green (a non-natural color).

Documenting the Set

Second priority: measure the set Include reference points, surfaces that

composited elements will touch, shadow, or be shadowed by.

Document on photographs of the set. Also measure positions of local light sources. Get position of camera's focal plane and lens

settings. They are used to construct 3D CG model.

Create CG Models

Main methods: Manual:

Create manually using software such as Maya. Good for geometric objects. Difficult to create complex objects with fine details.

Sculpt and Scan: Sculpt a model and then digitize using 3D scanner. Can create complex objects with fine details. Require artistry of sculptors.

CG Animation

Main methods: Manual:

Animate manually using software such as Maya. Tedious and time-consuming. Often used for animating facial expression.

Motion Capture: Capture human body motion using motion capture

system. Fast. Can visualize at real-time.

Digital Compositing

Combine all the visual elements, including Matting: separate foreground from background Blending: insert foreground into new background Transformation: change position, size, orientation Animation: move things around Match Move: match camera motion Match Color: match colors of visual elements Match Lighting: match lighting conditions

Summary of DFX Creation

Software Packages

Autodesk Combustion Adobe After Effects Apple Shake Autodesk Inferno Pinnacle Commotion Apple Motion eyeon Fusion D2 Nuke CompTime Industrial Light & Magic