Computer Graphics-Lab Assignment 7 Solved

1. Write down a Python program to draw a hierarchical model of boxes. 

A.       Set the window title to [studentID]-[assignment#]-[prob#] and the window size to 

(480,480). 

B.       Start from the following code skeleton. 

import glfw 

from OpenGL.GL import * import numpy as np from OpenGL.GLU import * 

 def render(): 

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)     glEnable(GL_DEPTH_TEST) 

 

    glMatrixMode(GL_PROJECTION)     glLoadIdentity()     glOrtho(-2,2, -2,2, -1,1) 

 

    glMatrixMode(GL_MODELVIEW)     glLoadIdentity() 

     

    drawFrame() 

    t = glfw.get_time() 

 

# blue base transformation     glPushMatrix()     glTranslatef(np.sin(t), 0, 0) 

 

    # blue base drawing     glPushMatrix()     glScalef(.2, .2, .2)     glColor3ub(0, 0, 255)     drawBox()     glPopMatrix() 

 

    # red arm transformation     glPushMatrix() glRotatef(t*(180/np.pi), 0, 0, 1) 

    glTranslatef(.5, 0, .01) 

 

    # red arm drawing     glPushMatrix()     glScalef(.5, .1, .1)     glColor3ub(255, 0, 0)     drawBox()     glPopMatrix() 
     glPopMatrix()     glPopMatrix() 

 def drawBox(): 

    glBegin(GL_QUADS)     glVertex3fv(np.array([1,1,0.]))     glVertex3fv(np.array([-1,1,0.]))     glVertex3fv(np.array([-1,-1,0.]))     glVertex3fv(np.array([1,-1,0.]))     glEnd() 

 def drawFrame(): 

    # draw coordinate: x in red, y in green, z in blue     glBegin(GL_LINES)     glColor3ub(255, 0, 0)     glVertex3fv(np.array([0.,0.,0.]))     glVertex3fv(np.array([1.,0.,0.]))     glColor3ub(0, 255, 0)     glVertex3fv(np.array([0.,0.,0.]))     glVertex3fv(np.array([0.,1.,0.]))     glColor3ub(0, 0, 255)     glVertex3fv(np.array([0.,0.,0]))     glVertex3fv(np.array([0.,0.,1.]))     glEnd() 

 def main():     if not glfw.init(): 

        return     window = glfw.create_window(480,480,'2017123456-lab6-1', None,None)     if not window:         glfw.terminate()         return 

    glfw.make_context_current(window)     glfw.swap_interval(1) 

     while not glfw.window_should_close(window):         glfw.poll_events()         render() 

        glfw.swap_buffers(window) 

 

    glfw.terminate() 

 if __name__ == "__main__": 

    main() 
C.       Add a green arm at the end of the red arm, and rotate the green arm about its local 

z axis. 

               i.          Render the green arm using drawBox(). 

D.       Also render local frames of the blue base, red arm, green arm using drawFrame(). 

E.       Expected result: Uploaded LabAssignment7-1.mp4 

F.        Submit a single .py file - [studentID]-[assignment#]-[prob#].py 

 

 

 

2. Write down a Python program to draw following triangular pyramid (삼각뿔) by using indexed triangles representation and glDrawElements().  

A.         

B.       Start from the code in 7-Hierarchy,Mesh slides. Make sure camera manipulation shortcuts 

‘1’, ‘3’, ‘2’, ‘w’ work.  

C.       Set the window title to [studentID]-[assignment#]-[prob#] and the window size to (480,480).