Obtaining Positional Data

[betancourtb82]

Ok, everything works great so far. The only problem is that I am getting some kind of traceback error.

Traceback (most recent call last):
  File "Test2WithEyeAdjustment.py", line 185, in mytimer
    avatar = avatars[nextAvatar]
IndexError: list index out of range

This occurs whenever I shoot an avatar and he disappears. When I double click on the error it highlights:

def mytimer(num):
	global avatars
	if num == ANIMATION:
		
		#Calculate elapsed time since last update
		elapsed = viz.elapsed()
		
		#Update each active ball
		for bullet in bullets:
			if bullet.active:
				#Move the ball and check if it has collided with any objects
				MoveBullet(bullet,elapsed)
		
	elif num == START_AVATAR:
		global nextAvatar
		#Get the next available avatar and start it
		avatar = avatars[nextAvatar]
		#favatar = favatars[nextAvatar]
		walkAvatar(avatar)
		#walkAvatar(favatar)
		nextAvatar = (nextAvatar + 1) % NUM_AVATARS
		viz.starttimer(START_AVATAR,TIME_BETWEEN_AVATARS)
#Create callbacks for timer events
viz.callback(viz.TIMER_EVENT,mytimer)

When I shoot the avatars, this function is called:

def shootBullet():
	global nextBullet
	#find the next available ball to shoot
	bullet = bullets[nextBullet]
	nextBullet = (nextBullet + 1) % NUM_BULLETS
	#Calculate the vector of the ball based on the mouse position
	pos = viz.mousepos()
	bulletvector = viz.screentoworld(pos[0]+0.25,pos[1]) #Need to account for stereo
	bullet.vector = viz.Vector(bulletvector[3]-bulletvector[0],bulletvector[4]-bulletvector[1],bulletvector[5]-bulletvector[2])
	bullet.vector.normalize()
	bullet.vector *= BULLET_SPEED
	
	#translate the bullet to the head position
	bullet.translate(viz.get(viz.HEAD_POS))
	
	#make the bullet visible
	bullet.visible(viz.ON)
	
	#mark the bullet as active
	bullet.active = 1

def MoveBullet(bullet,elapsed):
	#get the bullet's current position
	pos = bullet.get(viz.POSITION)
	
	#calculate the balls future position based on it's velocity
	futurePos = pos + (bullet.vector * elapsed)
	
	#Check if bullet intersected with anything
	info = viz.intersect(pos,futurePos)
	if info.intersected:
		if info.object in avatars:
			#viz.starttimer(FREEZE_AVATAR,info.object.getduration(7)-0.1)
			WaitThenFreeze = vizact.sequence( vizact.waittime(info.object.getduration(7)-0.05), vizact.speed_node(0) )
			info.object.execute(7)
			info.object.clear(viz.ALL)
			info.object.clear(viz.CURRENT_ACTION)
			info.object.add(WaitThenFreeze) #Add the action to the avatar
			RemoveAvatarAction = vizact.call(RemoveAvatar,info.object)
			info.object.add(RemoveAvatarAction) #Add action to remove avatar

		bullet.visible(0)
		bullet.active = 0
	
	#Update balls positions
	bullet.translate(futurePos.get())
#Shoot a ball whenever left mousebutton is clicked
vizact.onmousedown(viz.MOUSEBUTTON_LEFT,shootBullet)

What does the error mean? Can it be fixed

[farshizzo]

Hi,

That means you are trying to index into the avatar list with a value greater than the size of the list. Are you deleting items from the avatar list after you create it? If so then you need to change the way you increment to the next avatar:

nextAvatar = (nextAvatar + 1) % len(avatars)

[betancourtb82]

I'm still getting the same error. I'm not sure what is causing it. When a bullet "hits" or intersects an avatar, the following code is called:

if info.intersected:
		if info.object in avatars:
			WaitThenFreeze = vizact.sequence( vizact.waittime(info.object.getduration(7)-0.005), vizact.speed_node(0) )
			info.object.execute(7)
			info.object.clear(viz.ALL)
			info.object.clear(viz.CURRENT_ACTION)
			info.object.add(WaitThenFreeze) #Add the action to the avatar
			RemoveAvatarAction = vizact.call(RemoveAvatar,info.object)
			info.object.add(RemoveAvatarAction) #Add action to remove avatar

The RemoveAvatar function is:

def RemoveAvatar(avatar):
	
	avatar.visible(0) #Hide avatar
	avatar.speed(1) #Restore speed
	avatars.remove(avatar) #Remove from list
	dead_list.append(avatar) #Add to dead list

I tried using the len(avatars) modulus division but it still gives me the same traceback error.

I also tried:

		if len(avatars) != NUM_AVATARS:
			avatar = dead_list[nextAvatar]
			nextAvatar = nextAvatar + 1 % len(dead_list)
		else:
			avatar = avatars[nextAvatar]
			nextAvatar = (nextAvatar + 1) % len(avatars)
		walkAvatar(avatar)

but that didn't work either.