Description
Write down a Python program to draw a transformed triangle in a 3D space.
- Set the window title to your student ID and the window size to (480,480).
- Use the following code snippet:
gCamAng = 0
gComposedM = np.identity(4)
def render(M, camAng): # enable depth test
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) glEnable(GL_DEPTH_TEST)
glLoadIdentity()
# use orthogonal projection glOrtho(-1,1, –1,1, –1,1)
# rotate “camera” position to see this 3D space better gluLookAt(.1*np.sin(camAng),.1, .1*np.cos(camAng), 0,0,0, 0,1,0)
# 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()
# draw triangle glBegin(GL_TRIANGLES) glColor3ub(255, 255, 255)
glVertex3fv((M @ np.array([.0,.5,0.,1.]))[:-1]) glVertex3fv((M @ np.array([.0,.0,0.,1.]))[:-1]) glVertex3fv((M @ np.array([.5,.0,0.,1.]))[:-1]) glEnd()
def key_callback(window, key, scancode, action, mods): global gCamAng, gComposedM if action==glfw.PRESS or action==glfw.REPEAT:
if key==glfw.KEY_1:
gCamAng += np.radians(-10) elif key==glfw.KEY_3: gCamAng += np.radians(10)
- If you press or repeat a key, the triangle should be transformed as shown in the Table. Note that key 1 and 3 are already implemented in the above code snippet.
| Key Transformation | |||
| Q Translate by -0.1 in x direction w.r.t global coordinate | |||
| E Translate by 0.1 in x direction w.r.t global coordinate | |||
| A Rotate about y axis by -10 degrees w.r.t local coordinate | |||
| D Rotate about y axis by +10 degrees w.r.t local coordinate | |||
| W Rotate about x axis by -10 degrees w.r.t local coordinate | |||
| S Rotate about x axis by +10 degrees w.r.t local coordinate | |||
| 1 | Rotate camera -10 degree | ||
| 3 | Rotate camera 10 degree | ||
- Transformations should be accumulated (composed with previous one)
- Write down a Python program to draw a hierarchical model of boxes.
- Set the window title to your student ID and the window size to (480,480).
- 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() |
- Add a green arm at the end of the red arm, and rotate the green arm about its local z axis.
- Render the green arm using drawBox().
- Also render local frames of the blue base, red arm, green arm using drawFrame().
- Expected result: Uploaded LabAssignment8-2.mp




