Photorealistic Modeling

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Photorealistic Modeling
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3D

• Three-dimensional is a specific way of presenting
  a scene or an object.
• It is commonly used in computer animation,
  virtual reality, environment, etc.
• As most photorealistic renderings attempt to
  create as realistic a presentation as possible,
  and the human eye sees in three dimensions
  (pictorial drawings), rendering is recommended in
  3D.

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Artifact

• The physical work itself is an artifact an
  essay, a test, a drawing, a plotted drawing.
• This is important because photorealistic drawings
  often find their way into formal presentations
  and student portfolios.

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Background

• The background shows up behind the image in
  rendering.
• Many programs allow JPG files to be opened,
  adjusted or stretched to fit to form a
  background.

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Camera

• Many programs allow the perspective of the viewer
  to be changed before rendering by setting the
  camera angle.
• Its like pointing a spotlight at the object to
  highlight the particular desired view.
• The software may call this perspective instead of
  camera.
• When setting up, a camera is normally defined by
  a location XYZ coordinate, a target XYZ
  coordinate, and the field of view/lens length.
• In AutoCAD, the following steps show where the
  camera can go in the working environment Click
  Render tab Camera panel Show Cameras.

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Chronology

• Chronology is a form of presentation in which the
  order of events is fixed, for instance, an
  animation piece that shows the growth of a plant.
  
• Because animation takes a significant amount of
  time to photorealistic render each frame, it is
  recommended that students only photorealistic
  render one object with one frame for portfolios.

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Compatibility

• Compatibility is the transference of data from
  one program to another.
• For instance, modeling something and then moving
  it to another piece of software to photorealistic
  render the object.
• This is discussed in greater detail in the
  modeling section.
• One example is an object modeled in Autocad and
  sent to 3ds Max for animation and rendering.
• AUTOCAD 3DSMAX

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Computer Animation

• The chronological presentation of
  computer-generated material used to show an
  engineering idea (movement of a machine) or to
  entertain through cinema or digital art or to
  sell something through commercials.

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Digital

• Digital means something that is electronic
  binary numerical, or anything computer based.

Digital Reality

• A generic term which covers other sub-areas of
  computer-aided 'reality', such as photorealism.

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Environment

• A digitally created space where the user can move
  objects around on a scene, much like in the
  physical environment (rotate, change
  coordinates).
• The environment can also be adjusted in most
  rendering software for changes in atmospheric
  (fog, dust, smoke).
• Some software calls the background environment
  in their programming.
• It is normally the last thing modified when
  photo-realistic rendering objects and scenes.

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AutoCAD Rendering Environment

• The following slides show some slight
  manipulation in AutoCAD Rendering Environment.
• Note that the robot depicted was designed by an
  intro student and then a team of students
  constructed it from the foam used from the
  packaging from computer lab boxes.
• The actual robot was constructed and used at the
  2010 prom for Ringgold High School, Georgia.
• If a different software package is used, similar
  steps produce similar results.

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Original Design in a Multi-View Artifact
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Medium level rendered with the sky turned on in
environment and no artificial lighting natural
only
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Medium rendered, artificial lighting added in the
form of one spotlight from the top lined up to
the shoulder, sky turned on, and view changed to
isometric
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Modeling

• Digitally creating a three-dimensional object or
  space, especially in computer animation and
  virtual reality.
• Different software packages use different words
  for rendering effects.
• In modeling, most have a wire frame option that
  shows all the sides of an object, almost as if it
  were made of glass.

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REVIT Wire Frame
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FACE or HIDDEN LINE Grey Option

• Another option is the face where only the face of
  the object shown to the viewer is displayed, like
  a wire frame but all the lines behind the shown
  planes are not visible.
• Some software options include a grey scale where
  the object is shown in various shades of grey.

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REVIT Hidden Line
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Concept Shading

• Concept rendering shows an almost cartoon aspect
  of the textures and is more color driven than the
  grey or face display.
• Shading shows the color of the object without any
  or very little of the texture, depending on the
  software package.

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REVIT Shading (Red Brick Wall)
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Realistic

• Realistic rendering is the best most modeling
  software can do to mimic photorealistic where
  textures and colors and background are rendered.
• The best photo rendering like those displayed in
  cinema (think Avatar) either use software that
  does both modeling and rendering or was modeled
  in one software package and exported and rendered
  in another program that was developed just to do
  photorealistic rendering.

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Light

• In rendering, adding artificial light highlights
  what the user wants to focus on when natural
  light is eliminated.
• Most programs default to sunlight so nighttime
  views have to have the sun turned off in order
  to effectively show the artificial light.
• Some of the software have sun and locations
  located under geographic location. Others have it
  under the render commands.
• Note that the morning has longer shadows than at
  noon when the sun is overhead.
• The glow effect is an option available separately
  from light on a few of the software packages.
  Most will automatically glow if the artificial
  light is turned on when setting up the rendering
  operation, and natural light is turned off.

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REVIT Realistic Rendered Red Brick Sunlight
Only note there is a floor lamp in the upper
corner of the right angle walls
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REVIT- Realistic Rendered Red Brick Same scene
rendered artificial light onlyOne floor lamp in
the upper corner
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Photorealistic

• Ideally, the viewer would be unable to tell the
  difference between a real subject and a digitally
  generated object when object is photorealistic
  rendered.

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Ray Tracing

• Eliminates the need of transferring objects into
  triangles before rendering and significantly
  speeds the rendering process.
• Many software packages use ray tracing as an
  option to set variables like the coordinate
  systems, and textures alignment to the X-Y-Z axis
  system.

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Refraction

• Light bends as it travels through something. In
  rendering, refraction or index of refraction can
  be adjusted before rendering.
• When setting up rendering, sometimes under Ray
  Tracing, the ability to change the refraction is
  sometimes labeled IOR (Index of Refraction).
• The value of glass is 1.5 so if you are working
  to achieve a glass effect, use that value (1.5).

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Reflection

• Photorealistic rendering of the interrelated
  effects of lighting on objects and surfaces.

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Rendering

• Images are rendered to make them appear more real
  in the digital world.
• See modeling for more details as modeling and
  rendering go hand-in-hand in todays visual
  world.
• Note that often objects are photographed and then
  rendered through a process called
  physically-based rendering.
• The engineering design student is mainly
  interested in the synthetically based rendering,
  one modeled first and then presented through
  rendering.

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Texture

• The surface material of objects in virtual
  reality looks like wood, metal, and textiles when
  texture is applied. Texture reflects light and
  can range from a bright, shiny, mirrored
  appearance to a dull, light-absorbent appearance.
  

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Realistic View of Textured Spheres in AutoCAD
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Presentation Quality RenderingNo background, no
additional lighting
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WCS

• World Coordinate System
• The space where the objects reside (environment
  in some software packages).
• You can change the vertical and horizontal
  positioning of texturing using the UV options on
  a lot of software.
• Some software will give you options on the planar
  mapping to change the alignment (X-axis, Y-axis,
  Z-axis) and the orientation (horizontal or
  vertical).

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Software

• There are vocabulary and application differences
  between the various software packages currently
  available.
• The student that understands that basic concepts
  of light, texture, environment, and rendering
  will take this knowledge and apply it to the
  available software package.

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Journal Writing Assignment

• Take the following four words and write them on
  the top of your paper. Circle the one that you
  think is different from the other three.
• TEXTURE
• LIGHT
• ENVIRONMENT
• RENDERING
• Write two to three sentences about how the
  circled word is different.
• Write two to three more sentences explaining how
  the other three words are alike.