A* Pathfinding Project Released

[SteveB]

Sweet.

...and at the begining of my last post, could you point out where controller.StartPath is in your Seeker.cs script?


Too bad about multiple floors but, how 'high' can the terrain be? Is there a limit in the "Z axis" (if your grid were X and Y)? What is the criteria for an object to be considered an 'obstacle'? Interpenetration with the terrain or merely it's position above?

-Steve

[sturestone]

public AstarPath.Path StartPath (Vector3 start, Vector3 end) {

Line 49

There is no limit in z axis.
The script has several options for calculation if a node is walkable or not.
See http://www.arongranberg.com/unity/a-pathfinding/docs/interface/
(Capsule option is not added)

Overlap: Uses Physics.OverlapSphere to check if the node is walkable

Touch: Uses Physics.CheckSphere to check if the node is walkable (haven't found any differences between Touch and Overlap yet though)

Capsule (recomended) : Uses Physics.CheckCapsule, checks if any obstacles is inside or touching a capsule with a defined height.

Raycast: Raycasts down on/up from the terrain to see if it hits something. This will only return true if the obstacle touches the middle of the node.

[SteveB]

Awesome. I appreciate your patience in answering what may seem like simple questions. Rest assure I'm doing my best to work for the solution before asking, but again thank you so much.


-Steve

[sturestone]

Hi

Now I'm working on the next version of the A* pathfinding project.
I would like to know what features you would like to have added.
Please give a lot of suggestions, because I'm running out of ideas


This will be in the next update:
Support for changing environments (like placing a building in runtime)
Flood Fill Area calculation : avoid to calculate a path when there is no way we can travel between start and end.

[SteveB]

Hi Aron!

The most significant addition I can see is the ability to 'connect' grids to allow for multiple levels.

As discussed in the Visual Logic Editor thread, Virtools uses grids to both visualize pathfinding (similar to yours at run-time but these are interactive and have editing capabilities to define up to 256 layers and to 'paint' your own obstacles, etc).

The thing they allow are 'Linker' squares that connect two grids to each other for more complex environments. One example they have is an elevator that takes the character up from one grid on the ground floor to a grid way up high; the grid squares in front of the elevator on both levels are marked as 'Linkers' that essentially connect the two grids despite being separate and at two different locations.

To expand this, it could be nice to have an option to edit the grid again like in Virtools so we could 'paint' attributes into the grid such as triggers.

I'll think more on this, but let me know if this is even feasible.


-Steve

[sturestone]

Hi

I have also been thinking about linker nodes.
The script uses an array of all the neighbor nodes so basically I can add any node to that array and those nodes will be linked.
I have edited the code so it now uses a 3 dimensional array for the nodes instead of a 2 dimensional, so now I can have as many layers/floors as I want.
Tomorrow or in a couple of days I will add a node linking utility so I can execute pathfinding over multiple floors.
So linked nodes and multiple floors might be added to the next update

PS: I couldn't find anything about pathfinding with Virtools though, only one line in the thread.

[SteveB]

Wow sounds fantastic Aron! Looking forward to it...

...and yea my sentence was poorly constructed; I meant the conversation about "Virtools", not specifically pathfinding in Virtools...my bad.

-Steve

[sturestone]

I have managed to get 3d pathfinding between two grids now.
Works great.
Now there is only the linking utility left, currently it's hard coded.

[SteveB]

Well if you need someone to test it let me know! Hahaha...

...but really thats a significant addition IMHO so bravo Aron, wow.


-Steve

[liverol]

hi,sturestone,thanks for your great work,i hope this can be implemented in next version:control lots of units at the same time and they can wait when the destination is blocked and continue to move when free,all in a word,a mature RTS path moving solution,if possible,i would like to pay for a commercial license!

[sturestone]

I think I can implement multiple units calculating the path simultaneously. Waiting for the path to get free from other units is very simple, but depending on how realistic you want it it becomes increasingly complicated, it is also very project dependent, often you have a moving script already in the project and wants the A* script to fit it, so it's hard to write something that works in all cases.

[liverol]

just like the warcraft moving,is that possible?

[nikemerlino]

The project seems to have some problems in Unity 2.6. Is it only my problem?

[sturestone]

Nope, mine too.
I will release an update soon, and I will put in some new features too

[sturestone]

I must have missed that with warcraft moving, but here's an answer.

Yes, it is possible, it's very hard to make it fast enough though (working on it). Check out my new RTS demo (very early stage) here : http://arongranberg.com/wp-content/uploads/rts/rts
It uses the A* system version 2.2 (not yet released, although it is very similar to 2.0), the movement is very similar to warcraft movement.
You can select units by click n drag (it is not visible if you have selected a unit or not though), attack move with A + click and simple move with M + click or right click.