Learning Objectives - Multimedia Universitypesona.mmu.edu.my/~juhanita/MCC1013_2016_2017/lectures... · Viewing cameras vs. rendering cameras ... Scanline Renderer mental ray® Renderer

Learning Objectives

Lighting attributes Camera and rendering setup

Light, Shadow & Light Effects In the real world, there are many different type of light

sources ( for example, natural light the sun and artificial lights, light bulb, a flashlight, fire).

All light sources emit light (light rays) which canproduce four basic types of effects:

• Light

• shadow

• light effects

• illuminated fog

Light - When light shines on an object, it illuminates the object's surface.Without light, you could not see surfaces.

Shadow - When light shines on a surface, the surface may cast a shadow onto itself or other surfaces.

Light, Shadow & Light Effects

Optical light effect - When light shines directly into an observer's eye or into a camera's lens, may produce a glow, halo, or lens flare. Illuminated fog - When light shines through

the air, it may illuminate fine particles (fog, smoke or dust) that are in the air.

Light, Shadow & Light Effects

• Softness or hardness• Colour Temperature• Intensity• Direction and Movement

Characteristics of Light SourcesConsider the following characteristics of lightsource when planning your scenes.

• Artificial light, whether used indoors or outdoors at night, uses multiple lights.

• The Three-point lighting system is the classic Hollywood lighting scheme.

3 Point Lighting System

A key light is the main light that illuminates thecharacter or object. For outdoor scenes in thereal world, the key light is generally the sun.

A secondary light, often called a Fill Light because it fills in dark areas.

Backlights, if necessary, to distinguish the character or object fromthe background.

3 Point Lighting System

Other Properties of LightAngle of Incidence• The more a surface inclines

away from a light source, the less light it receives and the darker it appears.

• The angle of the surfacenormal relative to the lightsource

Attenuation In the real world, light diminishes

over distance. Objects far from the light source appear darker;

objects near the source appear brighter.

In nature, light attenuates at an inverse square rate. It is common for attenuation to be even greater when light is dispersed by the atmosphere, especially when there are dust particles in the atmosphere, or fog or clouds.

Other Properties of Light

Reflected Light and Ambient LightOther Properties of Light

Corrects the output level and colour range to better match what your eyes would see in real life 4 types of exposure control Automatic – good for still image where subtle effects are

used Linear – low dynamic range Logarithmic – high dynamic range

Pseudo – displays illumination levels in your scene using colours

Exposure Control

Standard lights are computer-based objectsthat simulate lights such as household or office lamps, the light instruments used in stage and film work, and the sun itself.

Different kinds of light objects cast light in different ways, simulating different kinds of light sources

Standard Lights in 3D

A spotlight casts a focused beam of light like a flashlight, a follow spot in a theater, or a headlight.

Standard Lights (Spotlight)

Directional lights cast parallel light rays in a single direction, as the sun does (for all practical purposes) at the surface of the earth. You can adjust the colour of the light and position and rotate thelight in 3D space.

Standard Lights (Directional Light)

An Omni light casts rays in all directions from a single source. Omni lights are useful for adding "fill lighting" to your scene, or simulating point source lights.

Omni lights can cast shadows and projections.

Single shadow-casting omni light is the equivalent of six shadow-casting spotlights, pointing outward from the center.

Standard Lights (Omni Light)

The 'Skylight' light models daylight. It is meant for use with the Light Tracer. You can set the colour of the sky or assign it a map.

The sky is modeled as a dome above the scene.

Standard Lights (Skylight)

Realism Sunlight Physically based on real-world light characteristics Enable to create physically accurate lighting. Best when combined with Global Illumination Attenuation and colour are automatically calculated

Photometric Lighting

Photometric Light Types Point Linear Area IES lights(Illumination Engineering Society): IES Sun- Sunlight IES Sky- atmospheric effects on skylight

Intensity is measured in lux (lx), lumen (lm)or candela (cd)

Combination of direct sunlight and indirect skylight

Simulates the sun and mimics movement over the earth at specific location.

Daylight

Local/direct illumination = takes into accountthe light that takes a direct path from the light source

Global illumination (GI)/indirect illumination =takes into account not only the lighting taking a direct path but also the light that has bouncedfrom other surrounding surfaces

Global Illumination

Heat/energy transfer

Describe the effect of light bouncing around in a scene When light bounces from one object to another, it not only

illuminates other objects but alsotransmits reflected colours.

Colour bleeding effect

Radiosity

Visual Function of shadows Types of shadows in 3Ds Max

Shadows

The Visual Functions of Shadows Revealing Alternative Angles Defining Spatial Relationship Adding To Your Composition Adding Contrast Indicating Off screen space Integrating Elements

Shadows

Defining Spatial Relationship

Adding to Your Composition

Adding Contrast

Indicating Off Screen Space

Integrating Elements

There are generally 2 types of shadows in 3D

Depth map shadows

Ray-traced shadows

Types of Shadows

Depth map shadows is created from Shadow Maps that is a bitmap or greyscale texture map created based on the lighting and mesh objects in the scene and then applies it to the objects at realtime.

A shadow-map is projected from the direction of the spotlight.

Depth Map Shadows

You can adjust the shadow map settings toachieve a sharper shadow. This involves changing the resolution and the pixel sampling of the shadow’s bitmap.

Depth Map Shadows

• Ray-traced Shadows are calculated and rendered by using raytracing rendere techniques.

• It generates ray-traced shadows by tracing the path of rays sampled from the light source.

Ray-traced Map Shadows

It casts accurate shadows from transparent, translucent and wireframe objects.

Ray-traced Map Shadows

Shadow Maps Ray-traced ShadowsSofter edge Always produce a hard edge

Faster calculation time Slower calculation time

Less accurate More accurate

Camera & Rendering Camera Types of camera in 3ds Camera tools

max

Rendering Preparing for render Types of renderers NPR

Camera Viewing cameras vs. rendering cameras

Whenever you look at your scene in 3D whetheryou are building your scene or ready to render images, you are looking through a camera.

Your field of view is restricted to what you cansee through that lens.

Camera By default, 3ds Max has four cameras that let

you view your scene in a panel: the perspective camera and the three orthographic cameras (side, top,

views.front) that correspond to the default scene

Camera tools

Types of camera in 3DS Max Target camera : has an eye position (the

location of the camera) and a target point (a3D point in space) where the camera is looking

Free camera : view the area in the directionthat the camera is aimed. Unlike Target cameras, which have two independent icons for the target and the camera back, freecameras are represented by a single icon,making them easier to animate.

Safe display regions for TV production Safe action - The safe action view guide

represents 90% of the rendering resolution (the resolution gate). Safe Title - The safe title view guide represents

80% of the rendering resolution

Clipping Planes Clipping planes are imaginary planes located at

two particular distances from the camera along the camera's sight line.

Only objects between a camera's two clippingplanes are rendered in that camera's view.

Rendering Rendering is the final stage in the 3D computer

graphics production process.

Though the wider context of rendering beginswith shading and texturing objects and lighting your scene, the rendering process ends when surfaces, materials, lights, and motion are processed into a final image or imagesequence.

Rendering your workYou essentially have two output types fromwhich to choose:Raster—Raster formats, such as QT MOV and Windows AVI, are flip books of still images, which means they can be rather large in size but very rich visually.3D geometry—3D output, such as VRML, MAX, DWG, 3DS, DXF or AI, allows you to choose your own viewpoint, as well as providing animation and behaviors through proximity triggers.

Renderers

mental images®

General-purpose rendererthat can generate physically correct simulations of lightingeffects, including ray- traced reflections and refractions, caustics, and global illumination.

The scanline rendererrenders the scene as a series of horizontal lines and renders from top to bottom.

Scanline Renderer mental ray® Renderer

The default renderer. The mental ray renderer from

Renderers

009

Renderers mental ray® Renderer The mental ray renderer is optimized to use

multiple processors and to take advantage ofincremental changes for efficient renderinganimations.

of

The mental ray renderer renders in formsrectangular blocks called buckets.

of

Non photorealistic renderingNPR is an area of computer graphicsthat focuses on enabling a wide variety of expressive styles for digital art.In contrast to traditional computer graphics, which has focused on photorealism, NPR is inspired by artistic styles such as painting, drawing, technical illustration, and animated cartoons.

Painterly Effect

Sketch

NPR has appeared in movies and video games in the form of "toon shaders," as well as in architectural illustration and experimental animation. An example of a modern use of this method is that of Cell-Shaded animation.

Non photorealistic rendering

Ink 'n Paint Material The Ink 'n Paint material creates cartoon effects.

Rather than the three-dimensional, realistic effect most other materials provide, Ink 'n Paintprovides flat shading with “inked” borders.

Alternative Renderers Brazil rendering system This is an alternative rendering system designed

for film, broadcast and visualization.

Brazil’s advanced algorithms and a modernarchitecture have led to a rendering system that cuts no corners to achieve any look required, including the highest levels in photorealism.http://www.cgarchitect.com/news/Reviews/Review012_1.asphttp://brazil-rs.blogspot.com/2007/08/tutorial-your-first-brazil-render.html

Alternative renderers• VRay has become the renderer of choice in big production studios

across the world. Feature film productions, multimillion dollar game productions, huge and small architectural visualizations have trusted their visuals to VRay.

• VRay has become the benchmark for speed used by many hardware vendors and other renderer developers to test against. Richest set of features, cost-effective and production ready.

http://www.averis.be/extra_tutorials/vray_basic_render_settings.htm

http://www.oman3d.com/tutorials/3ds/vray_ahmed3d/

http://www.chaosgroup.com/gallery/http://cg-india.com/Tutorials/V-Ray/3dsMax_tutorial_SL_01.htmlhttp://www.vrayelite.com/MBM_VrayElite/Html/onsite_tuts.html

Lesson Summary Rendering is the final stage in the 3D

computer graphics production process when surfaces, materials, lights, and motion are processed into a final image or image sequence. There is a lot of trial and error before you can

achieve the realistic render to mimic real world environment

ReferenceInside 3d Studio Max, Volume 2: Advanced Modelling andMaterials, Phillip Miller.Design First For 3D Artists, Geoffrey Kater3ds Max 9 User Reference

Foundation 3ds Max 8 Architectural VisualizationSmith

By Brian L.

www.3drender.comhttp://www.3dtotal.com/ Imageafter.comhttp://tutorialoutpost.com/tutorials/3d-studio-max/lighting/ http://www.pages.drexel.edu/~mcc36/digm212/tut/tut_main.htm http://www.artoolkit.org/Gallery/Radiosity/ http://graphics.ucsd.edu/~henrik/images/global.html

A very special thank you for Ms May Chan for the content of this lecture.