Our challenge was:

how to drag the button that opens the door, and "install" it in the lateral wall?

We find some code in the internet and make some modifications - the Lavoisier law :-)

We define the key p to be the key to be pressed when the pointer/cursor is over the button, to pick it. DON'T CLICK THE BUTTON! ONLY PUT THE POINTER OVER! Dragging the cursor we drag the object.

We define the keys: k and l to be pressed to rotate the button.

And the new code in the avatarobj script is:

-- etc.etc.
on control me
  --NEW!
 if keypressed("p") then   
  -- Find where the mouse is  
   spriteLoc   = the mouseLoc - point(sprite(1).left,sprite(1).top)
   
  -- Find the button and camera in  the 3D world
  butLoc      = myworld.model("but").worldPosition --button position
  cameraLoc   = cameraobj.mycam.worldPosition
  
  -- Find a (distant) point beneath the mouse, in the world
  distantLoc  = cameraobj.mycam.spriteSpaceToWorldSpace(spriteLoc)
  
  -- Create an imaginary line between the user's eye and this point
  ray   = distantLoc - cameraLoc
  
-- We need to work with a vector whose length is 1 unit
  ray.normalize()
  
  -- Determine which axis the camera is looking along
  cameraAxis  = cameraobj.mycam.transform.zAxis
  
  -- Do a little mathematics, based on the fact that the dotProduct of
  -- two perpendicular vectors is zero.
  vectorToBut   = butLoc - cameraLoc
  distanceToBut = (vectorToBut * cameraAxis) / (ray * cameraAxis)
  newLoc        = cameraLoc + (ray * distanceToBut)
  
  -- Move the button
  myworld.model("but").transform.position = newLoc
 
 end if

 --rotating the button
  if keypressed("k") then   
    turno = 2
  else
    if keypressed("l") then   
      turno = -2
    else
      turno = 0
    end if
  end if 
  
  steero = (steero + turno)*0.8
  if steero < -5.0 then steero = -5.0
  if steero > 5.0 then steero = 5.0 
  
  -- for button rotation
  myworld.model("but").transform.rotate(myworld.model("but").worldposition, upvect, steero)

 -- old code
  
  if keypressed(126) then   
    acc = 2
  else
    acc = 0
  end if 
 --etc. etc.

Play the demo. To pick the red button: mouseover the button and press the key: p. DON'T CLICK THE BUTTON! To move the button, drag the pointer/cursor. To let the button free: no more press the p key. To rotate the button: press the keys: k or l. The chalenge: "to install" the button in the lateral wall. The function of the button remains: clicking it you will open the door!

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