3D Modelling

1
3D Modelling

• Week 4
• Materials

2
Aims of today

• Discuss your assessments
• Presentation
• Portfolio
• Materials
• Why materials
• Working with materials in 3ds max
• Shaders and rendering
• Surface properties
• Applying maps
• Bitmaps
• Procedural
• Libraries
• Exporting materials

3
Your portfolio

• Create a series of non-trivial and novel 3D
  applications
• Build upon concepts taught in the tutorials
• Submission of paper screenshots
• Submission of electronic version
• On the disc you are expected to provide
• Webpages with critical reflection and links to
  your models
• Your models
• Copy of your presentation

4
Portfolio 4

• An interactive model of an object, added to your
  room. The subject of this object will be given to
  you in class. Marks will only be awarded for
  elements identified by you in your documentation
  and that go beyond the scope of the tutorials
  used in the teaching session.

• You choose one from
• A BBC Micro computer
• http//en.wikipedia.org/wiki/Bbc_micro
• A trading starship, a Cobra Mark III, from the
  game Elite
• http//en.wikipedia.org/wiki/Elite_(computer_game)
  
• A room or building from the Hope campus

5
Materials - a context

• To model furniture how would you apply material
  to an object to model
• A shinny metal chair?
• Wood surface on a chest of drawers?
• Marble vase?
• A glass table top?
• A tumbler with blackcurrant squash?

6
and more

• To display a wooden bowl, full of oranges?
• A video recorder?
• A stone fireplace?
• A metal light fitting, with the light turned on?
• A TV?
• A plastic chair?
• A magazine?

7
Concepts

• Consider modelling a brick wall
• Can you think of three ways to do it?
• Which would look best?

8
Using materials in 3ds max

• Use the library that comes with the software
• Or make you own
• Simple material
• Using a material texture
• Use a map
• Apply sections or in particular ways

9
Materials

• Materials are like paint
• With materials, you make apples red and oranges
  orange
• You put the shine in chrome and the polish on
  glass
• Materials are what make your scenes look real

10
Materials and light

• Light is reflected from the surfaces of your
  model
• Consider how the light and materials will
  interact
• Will it reflect its surroundings?
• Will it be bumpy or smooth?
• Old, clean or dirty?

11
Material editor

• Materials
• Defined
• Created
• Applied
• Sample shots
• Parameters
• Shaders
• Maps

3ds max v7
12
Standard materials

• You can create an unlimited number of materials
• The most important part of the material is the
  shader
• A mathematical formula that defines the way that
  a surface is affected by light
• You choose a shader according to the surface you
  hope to create

13
Rendering

• The computer paints the result of calculation
  onto the screen as an image
• Takes into account the geometry of the model, but
  also
• Colours
• Textures
• Light position, intensity, colour
• The viewport is a preview, you need to render the
  scene to see the materials properly

14
Shaders and rendering

• For standard materials, a shader is an algorithm
  that tells your software how to calculate surface
  rendering
• Each shader has a unique set of characteristics
  in order to serve a particular purpose

15
Maps and the Standard Material

• Think of the Standard Material as an easel
• The shader is the surface type
• Canvas, paper, metal
• Maps are the paintbrushes
• Use them to add colour and texture

16
Rendering modes

• Wireframe most basic
• Flat render single colour in the middle of the
  polygon
• Gourand or smooth renderer smoothly blended
  object surfaces
• Phong
• Blinn
• Ray tracing special type
• Reflections
• Radiosity
• Takes longer to render as it attempts to
  physically model a surface

17
3ds types of shaders

• Seven shaders used with a standard material
• Anisotropic For surfaces with elliptical,
  "anisotropic" highlights. These highlights are
  good for modeling hair, glass, or brushed metal.
• Blinn For rounder, softer highlights than Phong
  shading
• Metal For metallic surfaces
• Multi-Layer For surfaces with more complex
  highlights than Anisotropic
• Oren-Nayar-Blinn For matte surfaces such as
  fabric or terra-cotta
• Phong For surfaces with strong, circular
  highlights
• Strauss For metallic and nonmetallic surfaces.
  The Strauss shader has a simpler interface than
  other shaders.
• Translucent Similar to Blinn shading, the
  Translucent shader also lets you specify
  translucency, where light is scattered as it
  passes through the material.

18
Phong

• Smoothes the edges between faces and renders
  highlights realistically for shiny, regular
  surfaces
• Interpolates intensities across a face based on
  the averaged face normals of adjacent faces.
• Calculates the normal for every pixel of the
  face.

3ds max v7
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Blinn shading

• Blinn shading is a subtle variation on Phong
  shading
• The most noticeable difference is that highlights
  appear rounder

3ds max v7
20
Ray tracing

• Each pixel is calculated
• In 3ds max it uses mental ray renderer
• Generate reflections and refractions
• Ray tracing traces the path of rays sampled from
  the light source
• Reflections and refractions generated this way
  are physically accurate

3ds max v7
21
Reflections and Radiosity

• Ray-tracing algorithm takes into account
  reflections and radiosity

3ds max v7
22
Surface attributes

• Basic material settings
• Colour
• Shininess
• Transparency

23
Standard colour components

• Specular
• The colour of shiny highlights
• Diffuse
• The colour of the object in direct, "good"
  lighting
• Ambient colour
• The colour of the object in shadow

• Some shaders generate the specular colour, rather
  than letting you choose it.

3ds max v7
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Colour

• Hue
• Frequency of the light coming form the object
• Saturation
• How concentrated the colour is
• Value
• Lightness or darkness of a colour

• Additive colour model
• RGB

3ds max v7
25
Shininess

• Overall reflective nature of the object
• Specularity
• Intensity of the highlight
• Glossiness
• The size of the specular highlight

• Top sphere Glossiness100 Specular Level100
• Left sphere Glossiness50 Specular Level50
• Right sphere Glossiness0 Specular Level0

3ds max v7
26
Anisotropic highlights

• The Anisotropic shader creates surfaces with
  elliptical highlights
• Good for modelling hair, glass, or brushed metal

3ds max v7
27
Activity

• Use a box to create a tray or table top
• Create a 2 x 3 array of spheres on the top
• Save to use again
• Create 6 different materials and apply them to
  your spheres
• Polished steel, brushed aluminium, red dull
  plastic , red shiny plastic.

28
Transparency

• Transparency and opacity are opposites

3ds max v7
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Translucency and refraction

• A translucent material transmits light, but
  unlike a transparent material, it also scatters
  the light so those objects behind the material
  cannot be seen clearly
• Simulate frosted and etched glass

3ds max v7
30
Glow

• Appears to be lit from inside

3ds max v7
31
Activity

• Reopen your saved file
• Make a partially transparent glowing material
• Use the translucent shader
• Select self-illumination

32
Materials and maps

• Materials describe how an object reflects or
  transmits light
• Within a material, maps can simulate textures,
  applied designs, reflections, refractions, and
  other effects

3ds max v7
33
2D maps

• 2D Maps are two-dimensional images
• mapped onto the surface of geometric objects
• or used as environment maps to create a
  background for the scene
• Bitmaps can be used as 2D maps
• Other kinds of 2D maps are generated procedurally

34
Diffuse map

• An image is used as a diffuse map
• Applied to the surface of the object
• Overrides the base colour
• Wood grain
• Texture of fruit
• Marble

3ds max v7
35
Procedural maps

• Derived from mathematical equations
• Simple or complex
• Do not degrade when you zoom into them
• They are 3D
• Marble material goes through an object as if it
  were solid

3ds max v7
36
Mapping textures

• Mapping is a method of projecting pictorial
  information onto surfaces
• It is a lot like wrapping a present with wrapping
  paper

3ds max v7
37
Why use bitmaps?

• Stick a logo on something
• Making street scenes or urban landscapes
• Use with billboard
• Used with avatars
• The map is generated by a graphic artist
• Use with care in real-time modelling
• Why?

38
Tiling

• Repetition of an image over a large area
• Use less memory
• Can look too uniform
• Can get join patterns

3ds max v7
39
Face mapping

• Ignores any mapping coordinates
• Conforms the image to the faces
• Select the desired face
• Apply the image

40
Bump map

• Bump mapping makes an object appear to have a
  bumpy or irregular surface
• Manipulates the objects normals
• Does not affect the objects mesh

3ds max v7
41
Mapping coordinates

• Use x, y z coodinates

3ds max v7
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UVW co-ordinates

• Most material maps are a 2D plane assigned to a
  3D surface.
• The coordinate system used to describe the
  placement and transformation of maps
• Mapping coordinates use the letters U, V, and W
• The three letters preceding X, Y, and Z in the
  alphabet.

43
Activity

• Add a procedural map to your scene
• Wood
• Marble
• Change the colours and grain
• Add a bitmap to a material in your scene

44
Material libraries

• Materials used in a model are saved in the max
  file
• The software comes with libraries of materials
• Create your own materials
• Which can then be saved to a library for use on
  another project
• Make a library from a particular scene

45
Special libraries

• Ray trace
• Attempts to physically model a surface instead of
  simulating it
• Form of rendering that calculates rays of light
• Supports advanced transparency parameters such as
  fog
• Architectural
• Actual physical properties
• Use with photometric lights to model real-life
  objects

46
Activity

• Use the material library to add the following
• Clear glass
• Earth
• Clouds
• Mirror

47
Animated textures

• Use an animation or video
• A model of a TV
• May loop
• Think about transitions

48
Environments

• You can use an image as a background
• RenderinggtEnvironments

3ds max v7
49
Bitmaps for exported models

• Exported files do not always take colours or
  textures with them
• Bitmaps can be better, but you need to collect
  them
• With 3ds max use
• Utilities gt More gt Bitmap/Photometric Paths gt
  Path Editor gt Edit Resources

50
Activity

• Export your model as VRML
• Collect all the maps into a maps folder

51
Covered today

• Why materials
• Working with materials in 3ds max
• Shaders and rendering
• Surface properties
• Applying maps
• Bitmaps
• Procedural

52
Self assessment

• To model furniture how would you apply material
  to create
• Shinny metal
• Wood surface
• Marble
• A glass table top
• A tumbler with blackcurrant squash

53
Self assessment

• and more
• To display a wooden bowl, full of oranges
• A video recorder
• A stone fireplace
• A metal light fitting, with the light turned on
• A TV
• A plastic chair
• A magazine

54
References

• Giambruno M, (2002) 3D Graphics Animation, 2nd
  Edition, New Riders, ISBN 0-7357-1243-3
• Kerlow I. V., (2003) The Art of 3-D Computer
  Animation and Effects , 3rd Edition, John Wiley
  Sons Inc ISBN 0471430366
• Murdock K. L., 3ds max7 Bible, Wiley Publishing
  ISBN 0-7645-7971-1
• Screen shots taken from 3ds max 7 User Reference
  and tutorials
• Discreet, 3ds max6 fundamentals courseware,
  Autodesk ISBN 1-56444-976-9