Computer Graphics Assignment 1: Basic OpenGL viewer & drawing a hierarchical model

• Only accept answers submitted via git push to this course project for you at https://hconnect.hanyang.ac.kr (<Year>_<Course no.>_<Class code>/<Year>_<Course

no.>_<Student ID>.git).

• Place your files under the directory structure <Assignment name>/<your files> just like

the following example.

• The submission time is determined not when the commit is made but when the git push

is made.

1. Implement a basic OpenGL viewer and show an animation of a hierarchical model using the viewer. This viewer will also be used in future class assignments.
   1. You have to implement all requirements in a single program. This assignment DOES NOT require each requirement to be a separate program
   2. The window size doesnt need to be (480, 480). Use the larger window that is enough to

see the details of the viewer.

2. Requirements
   1. Manipulate the camera with mouse movement (50 pts)
      1. Refer the camera manipulation of Blender software.
         1. https://www.blender.org/download/
      2. The camera of your program should initially look at a target point, similar to that of Blender.
         1. Initialize the target point to the origin (0, 0, 0)

iii. Provide the following three camera control operations.

1. Orbit: Rotate the camera around the target point by changing azimuth / elevation angles. (MMB (mouse middle button) in Blender) (15 pts)
   1. Do not rotate the camera about a vector from the camera to the target point.
2. Panning: Move both the target point and camera in left, right, up and down direction of the camera (Shift-MMB in Blender) (15 pts)
   1. More specifically, translate both the target point and camera along u axis (left & right) and v axis (up & down) of the camera frame
3. Zooming: Move the camera forward toward the target point (zoom in) and backward away from the target point (zoom out) (Ctrl-MMB in Blender) (15 pts) A. More specifically, translate the camera along w axis of the camera frame
5. You MUST use the following mouse movement:
   1. Orbit: Click mouse left button & drag
   2. Panning: Click mouse right button & drag

C. Zooming: Rotate mouse wheel

1. Using above mouse movements is essential for scoring your assignment, so if you use any other set of mouse movement or keyboard shortcuts

for Orbit / Panning / Zooming, you wont get any score for them.

1. Use perspective projection
2. Draw a rectangular grid with lines (not polygons) on xz plane as a reference ground plane (similar to Blender). Choose number of rows and columns, size as you want. (5 pts)

1. Create an animating hierarchical model using OpenGL matrix stacks (40 pts).
2. The model should consist of 3D primitives such as boxes and spheres,
3. You can use drawCube() and drawSphere() in the last page, or your own drawing

functions (which should use only numpy, opengl, glfw).

• DO NOT use glut or glu functions to draw 3D primitives (e.g., glutSoildBox(), gluSphere(),) because they generate runtime crashes on some systems (maybe

problems of some python bindings, but dont use them anyway). iv. Because weve not covered shading yet, just draw your model in wireframe mode by calling the following function at the beginning of your render function:

1. glPolygonMode( GL_FRONT_AND_BACK, GL_LINE ) # call this at the beginning of

your render function

2. You can change the color of your wireframe primitives using glColor*().

1. You should use OpenGL matrix stack to draw and animate your hierarchical model.
2. The model should have a hierarchy of at least 3 levels (20 pts).
   1. For example, the following model has a hierarchy of 4 levels.

vii. Animate the model to show the hierarchical structure (20 pts).

1. Make all child body parts move relative to their parent body part.
   1. In the above example, part 2, 3, 4, 5, 6 should move relative to part 1, part 7 should move relative to part 2, part 11 should move relative to part 7, and

so on.

1. If any of the child bodies does not move relative to its parent, you will

get -10 pts.

2. You can make any hierarchical system freely. Be creative.
3. Eg) a hand with fingers bending
4. Eg) a runner with arms and legs swing
5. The model should be automatically animated without any mouse or keyboard

inputs.

3. Report (10 pts)
   1. Submit a report of at most 2 pages in docx file format (MS Word). Do not exceed the

limit.

1. The report should include:
   1. Which requirements you implemented (5 pts) ii. A few screenshot images of your program (5 pts)
2. You do not need to try to write a long report. Just write down the required information.

Use either English or Korean.

4. Runtime Environment
   3. Your program should be able to run on systems only with Python 3.7 or later, NumPy,

PyOpenGL, glfw. Do not use any other additional python modules.

1. Only glfw is allowed for event processing and window & OpenGL context management. Do not use glut functions for this purpose.
2. If your program does not meet this requirement, it will not run on TAs computer so

you will not get any score for this assignment (except report).

5. What you have to submit:
   1. .py files
      1. You can use multiple .py files for this assignment. In this case, explain how to run the

program in the report.

1. .docx report file

6. drawCube() and drawSphere() code: