## ENG 004 Lecture 10, Oct 30, 2012

### Announcements

• Homework #4 due now
• No homework for this week
• Midterm is Thursday, November 1
• The midterm will take place in Young 198

### Topics

• Parametric Constraints
• Feature Planning
• Review

## Design

• Design models: concurrent and linear, ETC/ARC
• Ram's Principles
• Design Thinking
• Visual Thinking
• Role of graphics in design: visualization, documentation, communication

## Sketching/Drawing

• Types of sketches: contour, upside down, detailed, technical, freehand, mechanical, CAD
• Standards, linetypes
• Proportions and use of contructions lines, miter lines
• Projection Types: multiview, axonometric, oblique, perspective
• Perspective: one point, two point, and three point
• Parallel projections: multiview, isometric, oblique
• First angle, third angle projections

## Sketching/Drawing

• Diagrams: tree, flow, Venn, engineering
• Grids: simple, square, iso, circle/ellipse
• Multiview drawings: 3D to 2D, miter line, oblique lines, circles, hidden lines, construction lines
• Choice of views, minimal # of views, view spacing
• Revolution conventions
• Isometric: 2D to 3D

## Coordinate Systems

• 2D: Cartesian (rectangular), polar
• 3D: rectangular, cylindrical, spherical
• Handedness: right/left
• Coordinate planes
• Absolute/relative coordinates
• World and Local coordinates

## Primitives

• 2D primitives: nodes/points, lines, arcs, circles, rectangles, curves from intersections, interpolated and Bézier curves
• 3D primitives: parallelpiped, sphere, cylinder, cone, space curve, surface patch, plane, surfaces
• Surfaces: general surface, ruled surface, generatrix/directrix, developed/undeveloped
• 3D models: node, surface, solid

## Constraints

• Implicit/Explicit
• Fully-, over-, under-constrained
• Closure, segment overlap, coincident, tangency, parallel, perpendicular, concentric, equal

## Solid modeling

• Sketch planes
• Boolean operations
• Constructive operations: extrude, revolution, sweep, loft
• Fillets/rounds, holes/bolts
• Feature planning

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