[WORK AROUND]Pandai avoidance assertion error !is_empty()

Scripting Issues
1

Hi, I am trying to make an agent avoid obstacles in a small world.
I added the collision nodepaths to the AiWorld object with the addObstacle method.
When I try running the script, I get the following error message:

Assertion failed: !is_empty() at line 1253 of panda/src/pgraph/nodePath.cxx

Traceback (most recent call last):
  File "test.py", line 189, in AIUpdate
    self.AIworld.update()
AssertionError: !is_empty() at line 1253 of panda/src/pgraph/nodePath.cxx
:task(error): Exception occurred in PythonTask AIUpdate
Traceback (most recent call last):
  File "test.py", line 876, in <module>
    run()
  File "C:\Panda3D-1.7.0\direct\showbase\ShowBase.py", line 2531, in run
    self.taskMgr.run()
  File "C:\Panda3D-1.7.0\direct\task\Task.py", line 496, in run
    self.step()
  File "C:\Panda3D-1.7.0\direct\task\Task.py", line 454, in step
    self.mgr.poll()
  File "test.py", line 189, in AIUpdate
    self.AIworld.update()
AssertionError: !is_empty() at line 1253 of panda/src/pgraph/nodePath.cxx

I saw in the manual examples that the NodePaths added to the AIWorld were the ones returned by loadModel method.
Do collision nodes work as well?

2

Perhaps one of the NodePaths you passed was an empty NodePath, such as when a model failed to load?

3

Nope.
I called the isEmpty method in the loop that add the
colliders, here is what I got:

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

Here is the code I am using, all the collision node paths I want the panda to avoid I added in a list, when I add a AIWorldObject, it will add every collider to this object as an obstacle.

	def addAiWorldObject(self, aiWorldObj):
		self.aiWorldObjetcsList.append(aiWorldObj)
		for collider in self.colliderList:
			print collider.isEmpty()
			aiWorldObj.addObstacle(collider)
4

I found a work around.
I have absolutely no Ideas why this works, all i did was to put the update method of the aiWorld object inside a try-except block (exption being “pass”).
It simply enter the exception block the first time then start working normally.

Again, I have absolutely no ideas why this worked.

5

I get a similar assertion problem if I try to enable obs_avoidance. I get the problem if i add obstacles to AIworld or not. I checked and the obstacles I added are not empty as well. Strangely, the example script works fine. Only difference I can tell is that the example does everything parented to render and I’m down the tree a little ways.

AssertionError: !is_empty() at line 59 of built/include/boundingSphere.I

6

I’m having the same problem as supus71. The main problem is that i haven’t knowledge about obstacles avoidance, so altough i manage to determine that the assertion that fails is
asking for the precondition of get_radious, that means nothing to me :confused: .
After making some blind research i could observe that the assertion doesn’t fail when i add few obstacles (like 2 or 3) to the aiWorld object, but as i increment the amount of
obstacles added, the assertion fails again. The initial distance between the objects doesn’t count.

7

PandaAI seems like it’s hard to use…