CSE325 Computer Science and Sculpture

1
CSE325 Computer Science and Sculpture

• Prof. George Hart

2
Lecture 4 Maya

• Maya is one high-end 3D design program out of
  many commercially available.
• It is available at Stony Brook in three CS labs
  and in the Art SINC site.
• It has a great many capabilities, of which we
  will explore only a few.
• This week we make geometric forms.
• Future week organic and human forms.

3
Some Comparable Programs

• Maya
• Blender
• Autocad
• Turbocad
• Rhinoceros
• 3D Max
• Solidworks
• Form-Z
• Inventor
• SketchUp
• Geomagic Studio
• Materialize

• Various Features
• Art vs. Engineering Design
• Animation
• Primitive Objects
• Operators
• File Formats
• Rendering
• Cost

4
Learning Maya

• Long learning time if you want to master all
  features, but we will focus on just a few.
• Representations include
• Polygonal Meshes Our focus this week
• NURBS
• Subdivision Surfaces
• Excellent built-in tutorials and help files.
• You can download the free Personal Learning
  Edition to learn from. (It doesnt save files
  in any standard format.)

5
Getting Started

• Make sure you have the Modeling menus selected in
  the drop-down box at top left
• Make sure you have the Polygons shelf tab
  selected.
• Buttons on shelf create a cube, sphere,
• ALT left, middle, or right mouse button move
  your point of view (the camera).
• Blue buttons on left put you in mode to move,
  rotate, or scale a selected object.

6
Getting Started

• Use the black buttons on left select Single
  Perspective View or Four View.
• Shiftclick to select multiple objects.
• 4 key Wireframe 5 key Shaded
• When working with polyhedra, to see the facets
  clearly, do this In the Shading menu of the
  view window, select Flat shade all and in
  Shade Options check Wireframe on Shaded

7
Exercise 1 Play

• Get familiar with primitive 3D objects
• Sphere, cube, cylinder, cone, torus
• Get familiar with simple operations
• Move, rotate, scale, chamfer, bevel, poke
• boolean union, intersection, and difference.
• Handy Keyboard shortcuts
• Undo ctrl-Z
• Duplicate ctrl-D
• Delete Del key
• For menu items, ? brings up an options panel.
• The channel box at right lets you type in
  properties.

8
Exercise 2 Compound of 3 Cubes
The object on the left tower is a compound of
three concentric cubes. To make it, create three
cubes, and rotate one 45 degrees on the X-axis,
rotate the second 45 degrees on the Y-axis, and
rotate the third 45 degrees on the Z-axis. To
get just the outer surface, take their Boolean
union.
M.C. Escher, Waterfall
9
Exercise 3 Octahedron

• Method Start with a 4-row, 4-wedge sphere, and
  keep only the six points on the axes
• Create 4,4, sphere
• Right-click to change from selecting objects to
  selecting vertices, edges, or faces.
• Delete the edges you dont need.
• Delete the vertices you dont need.
• Save your octahedron for later.
• (We will make it again by another technique in
  Exercise 5 below.)

10
Exercise 4 Octahedron Variations
Compound with cube requires proper scaling.
Stella Octangula can be made by poking an
octahedron
11
Octahedron Variations, Continued
Truncated octahedron has regular hexagons. (How
much chamfer?)
Chamfer 50 to get cuboctahedron
12
Exercise 5 Tetrahedron Variations

• Triangulate cube
• Flip edges as necessary so the six diagonals of
  the squares are tetrahedron edges.
• Delete 4 vertices not on tetrahedron with Edit
  Polygons Delete vertex
• (Save file for later)
• Duplicate, 90 degrees rotated, to make Stella
  Octangula a new way.
• Intersect two tetrahedra to make octahedron a new
  way.

13
Exercise 6 Rhombic Dodecahedron

• Poke cube to height which makes adjacent
  triangles merge into rhombi.
• Delete the twelve edges of the original cube.
• Poke it to make a stellated rhombic
  dodecahedron, which is the object on the
  right-side tower in Eschers Waterfall.

14
Exercise 7 Framework of Cube

• Subtract from a cube three scaled cubes, to leave
  just the edges of the original cube. Below is the
  first step

You can subtract out a fourth cube so the
interior of the corners looks like this
15
Exercise 8 Dodecahedron

• Intersection of 6 slabs. (slab cube which
  is short along one axis.) Each slab is given a
  31.7 degree rotation about some axis
• 2 X-axis slabs, rotated /-31.7 deg along Y
• 2 Y-axis slabs, rotated /-31.7 deg along Z
• 2 Z-axis slabs, rotated /- 31.7 deg along X
• Then save, chamfer, bevel, and poke it

16
Exercise 8 1/2 Warm-up

• Here is another way to make the octahedron,
  starting from a cube. It is good practice of a
  technique you will use in the next exercise to
  make an icosahedron from the dodecahedron
• Poke cube to create a vertex in center of each
  face.
• Edit Polygons / Texture / Merge UVs, (which
  allows flips in the next step).
• Flip edges of original cube to become octahedron
  edges. This makes the stella octangula again.
• Delete original cube vertices.

17
Exercise 9 Icosahedron

• Poke dodecahedron to create vertex in center of
  each face.
• Edit Polygons / Texture / Merge UVs
• Flip edges of original dodecahedron to become
  icosahedron edges
• Delete original dodecahedron vertices.
• Then save, chamfer, bevel, poke

18
Exercise 10 Edge Models

1. Duplicate the form
2. Scale one to be 10 smaller.
3. Use Extrude Face tool to build out a prism on all
   faces of the smaller one.
4. Take their Boolean difference.

19
Exercise 10 Some Ideas to Try
M.C. Escher, Stars
20
More Challenges

• Try some of Wentzel Jamnitzers constructions
• http//www.mathe.tu-freiberg.de/hebisch/cafe/jam
  nitzer/galerie7c.html