CS4182 Mid-term Quiz

计算机图形学代写 In the lecture, we learned the line clipping algorithm, in which the clipping region is a rectangular in 2D space. Please show…

  1. In the lecture, we learned the line clipping algorithm, in which the clipping region is a rectangular in 2D space. Please show the main idea for extending this algorithm in 3D space, i.e., clipping a line against a 3D cubic.
  1. Describe what transformation the matrix M performs when applied to 3D points.
计算机图形学代写
计算机图形学代写
  1. Briefly describe the main differences among computer graphics, image processing, and computer vision & image analysis.
  1. Write out the following three transformation matrices with homogeneous coordinates: 计算机图形学代写

?: translation along the vector ? =(4, 0,2)

?: rotation 30 degrees around the ?-axis.

?: non-uniform scaling with 2 in

??-axis, 3 in ?-axis and 4 in ?-axis

  1. As shown in Fig. 2,

(a) Assume the 3D plane has the uniform diffuse reflection property. If the light source is a directional light source, what is relationship between the diffuse reflections at points A and B? Please justify your answer 计算机图形学代写

(b) Assume the 3D plane has the uniform diffuse reflection property. If the light source is a point light source, what is relationship between the diffuse reflections at points A and B? Please justify your answer.

(c) Assume the 3D plane is a glossy surface. If the light source is a point light source, what is the relationship between the specular reflections at point B observed by viewers 1 and 2? Please justify your answer.

计算机图形学代写
计算机图形学代写

6. Which of the following scenes would cause problems for the painter’s algorithm? Please justify your answer and suggest a method to address the issue.

(These drawing are in image space; each rectangle is a single primitive)

  1. Are the following two polygons manifold? Please justify your answer. 计算机图形学代写

8.Please briefly explain Gouraud shading and Phone shading.

9.List four types of representations of 3D objects

10.What are homogeneous coordinates? And why are they introduced in transformations?

11.List all stages involved in the rendering pipeline.