Easy Pathfinding with NavGO

gameoffate2018 · January 13, 2021, 3:56am

Of course! I’m happy to help!

Jb_Skaggs · January 13, 2021, 4:07am

Success!

gameoffate2018 · January 13, 2021, 4:33am

I just put out version 15, which includes the directional NavGo nodes with labels to identify their number.

Please note, this only works during runtime, outside of runtime, all nodes will just display their ID as #, changing any one label will change all of them. For example, changing one label to “#1” changes all of the labels that refer to that specific game object.

The way to prevent this change is to create your own game object and add all of the parts to it like this:

Open up your collection and right click in the outline on the word “collection”

directional_6.png1036×1542 57.4 KB
Right click on the new game object you created and click on “add component file”, you will want to add in the directional NavGo script to the game object.

directional_7.png1036×1542 56.9 KB

directional_8.png1243×1581 83.4 KB
Right click on the new game object and hover over “add component”, this will open up a small side window where you need to select a sprite and a label.

directional_9.png1219×1767 186 KB
Within the sprite component, set the image to the NavGo atlas (/navGo_pathfinding/navGOAtlas.atlas) and set the default animation to be the directional node.

directional_10.png1219×1917 119 KB
Within the label component, set the Id to be “IdNumber”. Change the color to black. Change the position to be 0,0,.1 (this will show the label above the sprite). Change the text to be whatever you want on the node. Change the size to be 64,64,0. Set the font to be this link: /navGo_pathfinding/NavGOAssets/24-point-font.font

directional_13.png1219×1917 85.1 KB
Now you can cut/copy and paste this node and treat it like any other type of directional node, except that it can now have a different label in the editor. You should be able to even copy this across different collections to save yourself from having to do this in every level.

This is the end result of the above steps:

Jb_Skaggs · January 14, 2021, 4:28am

Today I was working on adding different enemies and the program started acting weird. So I reloaded the program as made yesterday which worked. Today though the same program no longer works. I added a print scripts showing what the characterGO stated as start and end and they all seem fine. But none of the objects will move. No nodes have been altered, I did not mess with any labels etc.

INFO:DLIB: Log server started on port 56845
INFO:ENGINE: Target listening with name: DESKTOP-T9J0991 - fe80::6864:d0a8:85fb:42cf - Windows
INFO:ENGINE: Engine service started on port 56846
INFO:ENGINE: Defold Engine 1.2.178 (af6a29c)
INFO:ENGINE: Loading data from: build/default
INFO:ENGINE: Initialised sound device 'default'
DEBUG:SCRIPT: Listening for debugger on 0.0.0.0
DEBUG:SCRIPT: Debugger connected from 127.0.0.1
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
INFO:DLIB: SSDP: Started on address 192.168.0.2
INFO:DLIB: SSDP: Started on address 192.168.56.1
DEBUG:SCRIPT: WARNING: NODE url: [main:/NavGO_NodeGO#NavGO_NodeScript] does not have any connections within range.
DEBUG:SCRIPT: -- NavGo is ready to be used
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND

Main Script:

function init(self)
	local message = {}
	message.collisions = { hash("wall") }
	message.debug = false
	message.deleteNodeAfterGotten = true
	message.nodeNeighborRange = 500
	message.nodeNeighborRange = 500
	msg.post("/NavGO_HandlerGO#NavGO_HandlerScript", hash("init"), message)
	timer.delay(1, true, function()
			local url = "#factory"
			local position = vmath.vector3(200, 200, 0) -- position where character spawns
			local rotation = vmath.quat_rotation_z(0) --quat angle the character spawns at
			local properties = { Start_path_ID = 1, End_path_ID = 100, speed = 400 } -- table of values to send to object
			local scale = vmath.vector3(0.5, 0.5, 0.51) -- scale to spawn at
			factory.create(url, position, rotation, properties, scale)
		end
		)
	end
	
function on_message(self, message_id, message, sender)
	if message_id == hash("NavGO_Ready") then
		print("-- NavGo is ready to be used")
		-- Add game start code
	end
end

character script

require("navGo_pathfinding.NavGO_Global")

go.property("Start_path_ID", -1)
go.property("End_path_ID", -1)
go.property("speed", 400)


local function distance(vec1, vec2)
	return math.ceil( math.sqrt( math.pow(vec1.x - vec2.x, 2) + math.pow(vec1.y - vec2.y, 2) ) )
end

local function moveCharacter(self)
	local path, found = NAVGO.GET_PATH_FROM_DIRECTIONAL_ID(self.Start_path_ID, self.End_path_ID)
	if not found then
		print("Directional - NO PATH FOUND")
	else
		print("Directional - PATH FOUND")
		local delay = 0
		local lastPos = go.get_position(go.get_id())

		for i=1, #path do
			local newPosition = vmath.vector3(path[i].x, path[i].y, 1)
			local time = distance(newPosition, lastPos) / self.speed -- move at a consistend speed
			go.animate(go.get_id(), "position", go.PLAYBACK_ONCE_FORWARD, newPosition, go.EASING_LINEAR, time, delay)
			lastPos = newPosition
			delay = delay + time
		end
		--timer.delay(delay, false, moveCharacter)
	end
end


------------------
--Core functions--
------------------

function init(self)
	timer.delay(1, false, moveCharacter)
	print("start")
	print(self.Start_path_ID)
	print("end")
	print(self.End_path_ID)
end

function on_message(self, message_id, message, sender)
	if message_id == hash("contact_point_response") then
		if message.group == hash("wall") then
			local newpos = go.get_position() + message.normal * message.distance
			go.set_position(newpos)
		end
	end
end

gameoffate2018 · January 14, 2021, 7:31am

That is super strange, I don’t see anything wrong with the code your provided. Based on the fact you reverted to an older version that used to work, that suggests a problem with the NavGo itself. Curiously enough, your prints do say that a path has been found from “Directional - PATH FOUND” message. If I had to make an educated guess, there is some sort of bug in my NavGo that I will look into.

Here are some possible fixes:

Try to change the master dependency to a versioned release, I suggest Alpha.13 : https://github.com/DrCampbell2017/NavGO/archive/Alpha.13.zip . This version doesn’t have the labels added in, but you should be able to check if it works or not. If it does, that means there is a problem with the NavGo I need to look into. Keep progressing forward with the versioned released until you hit one which doesn’t work.
In the character.script, add a print statement before the for loop like this:
print(“Number of nodes in path” … tostring(#path))
That should show you how long the path is, if it prints 0 or nil, some sort of error has occurred I’ll need to patch.

As a side node, you can removed this chunk of code from the character.script. This code does not effect the NavGo but could cause something to get stuck if you have a collision group called “wall”.

function on_message(self, message_id, message, sender) 
  if message_id == hash("contact_point_response") then 
    if message.group == hash("wall") then 
      local newpos = go.get_position() + message.normal * message.distance 
      go.set_position(newpos) 
    end 
  end 
end

Any more information you could provide me would be helpful. Please let me know what you figure out!

Jb_Skaggs · January 14, 2021, 7:33am

I went back ver 11 and its working.

I was going to work forward there and see what happens.

Jb_Skaggs · January 14, 2021, 7:41am

print(“Number of nodes in path” … tostring(#path))

this doesnt work: /main/directional_character/directionalCharacterSingleton.script
Line 20: Compilation failed: unexpected symbol near ‘…’

gameoffate2018 · January 14, 2021, 7:43am

My bad, that’s a typo should be:

print(“Number of nodes in path” .. tostring(#path)) --2 dots now instead of 3

The last change I made to the NavGo handler was version 12, after that, everything I changed was node-side such as adding in labels. I’m running tests now to see what could have changed elsewhere.

Jb_Skaggs · January 14, 2021, 7:46am

ver 13: obj shows up but doesnt move

DEBUG:SCRIPT: Number of nodes in path10
DEBUG:SCRIPT: is calling go.animate
DEBUG:SCRIPT: start
DEBUG:SCRIPT: 1
DEBUG:SCRIPT: end
DEBUG:SCRIPT: 100
DEBUG:SCRIPT: Directional - PATH FOUND
DEBUG:SCRIPT: Number of nodes in path10
DEBUG:SCRIPT: is calling go.animate
INFO:DLIB: SSDP: Done on address 192.168.0.2
INFO:DLIB: SSDP: Done on address 192.168.56.1

Jb_Skaggs · January 14, 2021, 7:51am

here is the project with 15 removed and 13 loaded

My Project - with navgo ver 13.zip (3.4 MB)

gameoffate2018 · January 14, 2021, 7:52am

It’s super strange to me that version 12 runs but 13 doesn’t. Everything is still working fine within the sample project on my end. If you download the master branch from github and run the sample project, does it still work on your end?

Jb_Skaggs · January 14, 2021, 7:52am

Maybe this will help you see if its my code or yours.

Jb_Skaggs · January 14, 2021, 7:54am

Yes I can run the sample codes and edit them.

The reason why Im fixated on this one is to see why it happened- if I accidently overwrote something or id it is a bug. So I can avoid in future.

Jb_Skaggs · January 14, 2021, 8:06am

BTW what time is it where you are? 2am here.

gameoffate2018 · January 14, 2021, 8:12am

It’s 3am here, I may call it a night soon.

Some thing I noticed, the enemy node you have is still moving, if I add in an update function like this:

function update(self, dt)
	print("My position is: " .. tostring( go.get_position() ))
end

You can see the position changing as it moves across the screen. Stranger still, is that when you change the timer in the main script from repeat = true to repeat = false. The character just seems to vanish.

I figured it out, kinda. When I change this line from within the character script from

local newPosition = vmath.vector3(path[i].x, path[i].y, 1)

to:

local newPosition = vmath.vector3(path[i].x, path[i].y, 0)

The node is visible and will travel around the screen properly. It existed the entire time but was somehow being rendered out, with the new node spawning every second, and the old node waiting a full second to move, it gave the appearance of it not moving while it was moving just above or bellow the render area. I am fully lost on why this happens between version 12 and 13, but it is still working, which I think is a good thing.

Jb_Skaggs · January 14, 2021, 8:18am

Thank ye kind sir Im ready for bed to. Had my chemo pump removed today and Im worn down. Ill check into this morrow.

This is a good learning experience for me. Education comes with pain.

Edit: Yep that worked!

Good night!

gameoffate2018 · January 15, 2021, 5:24am

Congrats on getting the chemo pump removed!

To explain what happened and why the balloon was rendered out. Without using some form of camera plug-in or changing the render property, Defold will only render in objects between the z-axis of -1 and 1. The objects not rendered still exist and can move about, but will not be displayed to the player during runtime. With your project, the character was being moved to the z-axis of 1 by my NavGO, then having the sprite be at 1 also put it above the upper limit and caused it not to be displayed. If you wanted to leave the z-axis stuff alone, you can fix it by using something like this in the main.script:

msg.post("@render:", "use_stretch_projection", { near = -2, far = 2 })

I also recommend changing the background sprite you are using to a z-axis of -1 so that balloons don’t actually spawn under it.

Here’s a reference to the rendering: https://defold.com/manuals/render/
Here’s a reference to the camera component: https://defold.com/manuals/camera/

I recommend not touching either the rendering stuff or trying to program your own camera, it takes a lot of time and unless you have a highly specialized reason to do so, it is not the best use of time. I personally think it is better to use one of the camera plug-ins. I personally recommend this one by britzl : https://github.com/britzl/defold-orthographic

Jb_Skaggs · January 14, 2021, 4:07pm

Thank you for answering my question before I asked it!

Jb_Skaggs · January 14, 2021, 11:01pm

Updated proof it works

Thank you Dr Campbell for all your hard work on this project.

gameoffate2018 · January 15, 2021, 5:23am

That looks great!

Thank you for using it! I’m glad it works well for your project, don’t be afraid to let me know if you need any bug fixes or features added to the library!