Department of Mechanical Engineering National Institute of Technology Jamshedpur Deepak Kumar, Department of Mechanical Engineering, NIT Jamshedpur [email protected] Computer Aided Design/Computer Aided Manufacturing
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
3D Scaling National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
The position vector is assumed to be a row vector in right-handed system National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
Polynomial Fit National Institute of Technology Jamshedpur
National Institute of Technology Jamshedpur
National Institute of Technology Jamshedpur
National Institute of Technology Jamshedpur
Parametric Continuity Conditions To represent a curve as a series of piecewise parametric curves, these curves to fit together reasonably …Continuity! National Institute of Technology Jamshedpur
Continuity When two curves are joined, we typically want some degree of continuity across the boundary (the knot) C , “C-zero”, point-wise continuous, curves share the same point where they join Let C 1 (u) and C 2 (u) , be two parametric Curves. C 1 (1) = C 2 (0) National Institute of Technology Jamshedpur
C 1 , “C-one”, continuous derivatives, curves share the same parametric derivatives where they join C´ 1 (1)= C´ 2 (0) National Institute of Technology Jamshedpur
C 2 , “C-two”, continuous second derivatives, curves share the same parametric second derivatives where they join Higher orders possible C˝ 1 (1)= C˝ 2 (0) National Institute of Technology Jamshedpur
Interpolation Splines When polynomial sections are fitted so that the curve passes through each control point, the resulting curve is said to interpolate the set of control points. National Institute of Technology Jamshedpur
Approximation Splines When polynomial sections are fitted to the general control point path without necessarily passing through any control point, the resulting curve is said to approximate the set if control points.
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
PROJECTIONS 1. Parallel Projections a) Orthographic Projections b) Axonometric Projections 2. Perspective Transformations and Projections National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
PERSPECTIVE PROJECTIONS 1. Perspective Transformations and Projections a) Single point b) Two point c) Three Point 2. Vanishing points and trace points National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
PLANE CURVES 1. Analytical Curves 2. Synthetic Curves National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
Parametric Representation of Curves and Surfaces Two types of equations for curve representation (1) Parametric equation x, y, z coordinates are related by a parametric variable ( u or θ) (2) Nonparametric equation x, y, z coordinates are related by a function National Institute of Technology Jamshedpur Department of Mechanical Engineering
Curve Equations National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
Parametric Equations –Advantages over nonparametric forms National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
y x Curve Fitting Data point approximated by straight Line National Institute of Technology Jamshedpur Department of Mechanical Engineering
Is a straight line suitable for each of these cases ? National Institute of Technology Jamshedpur Department of Mechanical Engineering
Polynomial Fit National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
National Institute of Technology Jamshedpur Department of Mechanical Engineering
Parametric Continuity Conditions To represent a curve as a series of piecewise parametric curves, these curves to fit together reasonably …Continuity! National Institute of Technology Jamshedpur Department of Mechanical Engineering
Continuity When two curves are joined, we typically want some degree of continuity across the boundary (the knot) C , “C-zero”, point-wise continuous, curves share the same point where they join Let C 1 (u) and C 2 (u) , be two parametric Curves. C 1 (1) = C 2 (0) National Institute of Technology Jamshedpur Department of Mechanical Engineering
C 1 , “C-one”, continuous derivatives, curves share the same parametric derivatives where they join C´ 1 (1)= C´ 2 (0) National Institute of Technology Jamshedpur Department of Mechanical Engineering
C 2 , “C-two”, continuous second derivatives, curves share the same parametric second derivatives where they join Higher orders possible C˝ 1 (1)= C˝ 2 (0) National Institute of Technology Jamshedpur Department of Mechanical Engineering
Interpolation Splines When polynomial sections are fitted so that the curve passes through each control point, the resulting curve is said to interpolate the set of control points. National Institute of Technology Jamshedpur Department of Mechanical Engineering
Approximation Splines When polynomial sections are fitted to the general control point path without necessarily passing through any control point, the resulting curve is said to approximate the set if control points. National Institute of Technology Jamshedpur Department of Mechanical Engineering