Computer Visualization

BIM Curriculum 03

Topics

History Computer Visualization Methods Visualization Workflow Technology Background

Technology Timeline

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http://accad.osu.edu/~waynec/history/timeline.html

Visualization Techniques Photorealistic

images (rendering) Artistic images Fly through

animations Sun studies Virtual Reality (VR)

NHS office complex by paastudio

Standard BIM Visualization Workflow

Images

Animations

VR

BIM Model

RenderingEngine

VREngine

AnimationTool

BIM APPLICATION

Complex Visualization Workflow

Images

Animations

VR

ExternalRenderingApplication

ExternalVR

Application

ExternalAnimationApplication

BIM Model

BIM APPLICATION

ExternalMovie-editingApplication

ExternalImage-editing

Application

Photorendering

Objective: Creating photorealistic

images based on the BIM model using an internal or external rendering engine

Process:1. Modeling2. Scene layout setup 3. Rendering

NHS office complex by paastudio

Scene Layout Setup

1. Adjusting the materials Texture positioning Color adjustment Shininess Bump mapping, transparency

2. Light Settings General light Sun light Brightener lights

3. Placing Cameras Positioning Camera angles

Computer Shading Techniques

Flat ShadingShades each polygon of an object based on

the angle between the polygon's surface normal and the direction of the light source

Gouraud ShadingSimulates the differing effects of light and

color across the surface of an object

Phong Shadingimproved version of Gouraud shading that

provides a better approximation of light and color

http://www.wikipedia.org/

Computer Rendering Techniques

Ray Tracingis a general technique of studying the

path taken by light by following rays of light as they interact with optical surfaces

simulate light reflecting only once off each surface

Radiosityis a global illumination algorithm that

simulate the many reflections of light around a scene, generally resulting in softer, more natural shadows and reflections then Ray Tracing

http://www.wikipedia.org/

Advanced Rendering Techniques

Texture mappingWrapping a texture image onto a

surface to create a realistic representation

Bump mappingSimilar to texture mapping but the

map image adds roughness to the model

Depth of FieldObjects appear blurry when too far

in front of or behind the object in focus

http://www.wikipedia.org/

Non-photorealistic RenderingsObjective: Creating artistic style images based on the BIM

model using special rendering engine and/or photo editing software

Process A:1. Modeling2. Scene layout setup 3. Non-Photorealistic Rendering

Process B:1. Modeling2. Scene layout setup 3. Photorealistic Rendering4. Modifying the image in a photo-editing

software

NHS office complex by paastudio

Non-photorealistic Renderings

Images were made with Piranesi software from Informatix

Artistic rendering applications support various painting styles:

Pencil Ink Ball-Pen Water-colour Oil-colours

Fly Through Animations

Objective: Creating movies of the building

along a predefined camera path, based on the BIM model, using internal or external animation tools

Workflow1. Modeling2. Scene layout setup3. Defining camera path4. Movie calculation

Animation Basics Animation is the optical illusion of motion created by

the consecutive display of images of static elements. In computer animations each frame of the movie is

produced individually by a computer software. When the frames are strung together there is an illusion

of continuous movement Typical Frame rates are 12-25 frames per second

http://www.wikipedia.org/

Sun StudiesThe sun study is a special type of

computer animation. The objective of making sun studies is to visualize the natural lighting conditions on a given location of the building at a particular day of the year. Unlike in fly through animations the camera position is fixed while the sun location is continuously changing

Workflow1. Modeling2. Scene layout setup3. Day settings4. Sun study calculation

Virtual Reality (VR) Virtual Reality (VR) is an environment that is

simulated by a computer. Most virtual reality environments are primarily for

visual purposes VR-s provide more freedom for the users in

exploring the building then pre-recorded animations

Workflow1. Modeling2. Scene layout setup3. VR camera settings4. VR calculation

QuickTime VRQuickTime VR is a type of interactive movie

supported by Apple's QuickTime file format. QTVRs can be "stitched" together from several normal photographs, or captured with specialized panoramic cameras, or rendered from 3D-modelled scenes. There are two types of QuickTime VR-s:

QuickTime VR (QTVR) Panoramas are panoramic images which surround the viewer

with an environment (inside, looking out), providing a sense of place.

QuickTime VR (QTVR) Objects are captured from many locations pointing in

toward the same central object.