Week 6 Tutorial
Question 1
Let’s say you were now working for a new Internet startup called CustomCar, which allows the user to visit their web site, set various options such as different types of wheels, various body types, different types of seats, spoilers etc. and then order it (don’t laugh, people are seriously proposing this as a business model). They want to show their car being animated, and sometimes only pieces of it being animated (e.g, the wheels spinning, or the car seat being put back). They also are worried about the size of the model in the computer’s memory. They’ve hired you, a proud graduate of COMP3421 as a consultant.
(a) Develop an approximate scene graph for a car.
(b) How does the scene graph give you flexibility in terms of
modelling customer choices?
(c) How does the scene graph give you flexibility in terms of
animating? Consider various types of animation and how you would
implement them.
(d) How would the scene graph help reduce memory footprint?
(e) What types of modelling would you use for different parts of the
car, e.g, surface, wheels, dashboard, windows, muffler system?
Question 2
Use the line clipping algorithm discussed in class to clip the line shown below against the rectangle below. That is, work out the equation of the line in parametric form, substitute the equation of the line into each of the four inequalities that represent the sides of the windows to get four inequalities in t, combine those inequalities to get the maximum and minimum t of the clipped line and substitute those t values back into the parametric equation to find the co-ordinates of the ends of the clipped line.
Question 3
Our eye is located at (0,0,-4) and we are projecting onto the XY plane (ie we can use the perspective projection matrix given in lectures).
Draw the result of projecting the cube with corners A (0,0,0), B (1,0,0) C (1,1,0) D (0,1,0) E (0,0,1) F (1,0,1) G (1,1,1) H (0,1,1) onto the XY plane.