python - PyOpenGL or OpenGL picking question (Not color picking)

Question

I have a small python program that uses PyOpenGL libraries to draw to spheres. The code has the below process

• draw spheres

  if there is a hit, then uses the below

  SELECT_BUFFER_SIZE = 512
  x, y = event.x(), event.y()
  # required to call this to force PyQt to read from the correct, updated buffer
  viewport = glGetIntegerv(GL_VIEWPORT)
  # print viewport
  w = viewport[2] - viewport[0]
  h = viewport[3] - viewport[1]
  aspect_ratio = w / h
  
  
  glSelectBuffer(SELECT_BUFFER_SIZE)
  glRenderMode(GL_SELECT)
  
  glInitNames()
  glPushName(0)
  
  glMatrixMode(GL_PROJECTION)
  glPushMatrix()
  glLoadIdentity()
  gluPickMatrix(x, viewport[3] - y, 5, 5, viewport)
  
  glOrtho( *** setting the schene***) 
  
  **-draw spheres using glLoadName(for each)**
  
  glMatrixMode(GL_PROJECTION)
  glPopMatrix()
  glFlush()
  
  buffer = glRenderMode(GL_RENDER)
  
  # print buffer
  for hit_record in buffer:
      _, _, names = hit_record
      print(names)
  

But when I try to print the names, although I hit only one of them on the window, both names are printed. What should be the solution for that

In short, I am trying to draw three spheres(in white color) in a Pyqt5 window using PyOpenGL with the same colors, but I am trying to make them eligible for picking. I have also the capabilities of rotating, moving, and zoom in-out. So these capabilities should not break picking when they are done.(As it is asked in the comment, it is not homework. It is a side project that I work on for the last 2 years. So this problem is only a really small portion of my code.)

question from:https://stackoverflow.com/questions/65836295/pyopengl-or-opengl-picking-question-not-color-picking

Answer 1

I'm not too sure at all that this will help
and I confess that I didn't read the actual code,
and I didn't quite understood if the spheres were colliding between them or with the border itself

I once had a tiny bit similar problem that I couldn't understand for too much time.
but basically a hit was printed twice because both of the objects were registering a hit,
so whenever they've hit each other two hit messages were printed.

I used their ID(or place in a list or something similar)
so only one of them (the one with the bigger ID) will print the message

I have no idea if that helps but it might just be it.