PyODE head family tutorial 3 was carried out

Original PyODE site

"Tutorial 3" is a sample of contact judgment. The visualization is PyOpenGL. -PyOpenGL setup is required. -Since it is OpenGL, there are many visualization code descriptions because it is 3D.

I have used OpenGL in C / C ++, so I rarely read this code (because I had an idea of what I was doing). I don't know.

PyOpenGL setup

It was a little difficult. ・ Https://www.lfd.uci.edu/~gohlke/pythonlibs/#pyopengl I got "PyOpenGL-3.1.5-cp38-cp38-win_amd64.whl" from and installed it with pip. → Tutorial 3 works normally.

It did not work normally from pip automatic acquisition. Click here for details → PyOpenGL setup with Python3 By the way, it seems that "PyOpenGL_accelerate" is also included with pyopengl, but I have not installed it yet.

result

"Tutorial 3" has moved. I added an image saving routine to make a GIF movie. (Use Pillow)

・ The value of the viewpoint has been changed from the original code.

Image storage routine

Outputs a PNG image group and one GIF video as a file. Only the additional part will be placed on ↓.

I thought that the original code did not have image output, so I added it like this, but I may have overlooked it.

How to use: -Install "Pillow". -Create two current folders "img" and "gif" in advance before execution. -Call the additional routine "capture ()" after the original line 231 "glutSwapBuffers ()". ・ Similarly, on line 220, call "export_movie ()" before "sys.exit (0)".

`Generate snapshot from PyOpenGL/Save`


from PIL import Image
from PIL import ImageOps

step=-1
intvl = 10
imgs = []
def capture():
  global step
  step += 1

  if step % intvl != 0:
      return

  pad_step = '{0:04d}'.format(step)
  print( pad_step )
  savepath = "img/tutorial3_"+pad_step+".png "
 
  width = glutGet(GLUT_WINDOW_WIDTH)
  height = glutGet(GLUT_WINDOW_HEIGHT)
 
  glReadBuffer(GL_FRONT)
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
  data = glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE)
 
  #image = Image.fromstring("RGBA", (width, height), data)
  image = Image.frombytes("RGBA", (width, height), data)
  image = ImageOps.flip(image)
  image.save( savepath )
  imgs.append( image )

`GIF video save routine`



def export_movie():
    if not imgs:
        return
    imgs[0].save('gif/tutorial3.gif'
               , save_all=True
               , append_images=imgs[1:]
               , optimize=False
               , duration=100 #40
               , loop=0)

PyODE Tutorial 3