[WONTFIX] Can NavigationMesh be combined with NavigationSector?

[ivan.cuevas]

Hi all,

Ungine docs warns about the impossibility to use two navigation meshes to compute a route.

I tried to compute a path intersecting a NavigationMesh with a NavigationSector and it isn't possible either. I don't know if it's my fault or it's an engine limitation.

 

What I want to achieve is to have a building with several floors, where the rooms and the corridors are identified and can have declared fire incidences. The desired solution would be to define a navigation mesh for each room or corridor connected by navigation sectors  to be able to use the navigation area danger factor to define the best route.

Any advice?

 

Thanks in advance.

[unclebob]

Hello, Iván!

 

There're no warnings about impossibility in the documentation, it tells you how to prepare navmesh properly. Also, I dig inside engine's pathfinder code and it looks it actually supports path creation between multiple navigations.

 

The algorithm the engine does is simple:

 

1) Take start navigation and target navigation;

2) If they're the same then just create a path and return it;

3) If they're not, look for entry points in the neighbour navigations and try to create path there until it reaches target navigation.

 

So if you have overlapping navigation nodes it should work. If it doesn't then it's better to isolate that case in a simple scene so we can reproduce it on our side. Also, try to play with height parameter in NavigationMesh nodes.

 

Please take my apologies for the long answer.

[ivan.cuevas]

Hi Andrey,

Thanks for the advices. We are going to follow your indications. if we can't achieve it, I will send you a test scene.

 

Please take my apologies for the long answer.

No problem, I know you are quite busy with Unigine 2.

[ivan.cuevas]

Here is a simple sample combining sectors and meshes for navigation.

The first route it's solved because it's in the same area, but If you move the closest navigation sector to be inside the target point the route fails (it also fails if you change target coords to be inside that sector).

 

Thanks.

sector03.zip

[unclebob]

Thanks for the sample, Iván!

 

I'll have a look at it and report back.

[unclebob]

Looks like it's a bug, passed to our dev team. Can't give any ETA unfortunately as our guys are participating in SIGGRAPH in China.

 

Thanks again, Iván!

[ivan.cuevas]

Next SDK will be enough ;D

Thanks to you!

[unclebob]

One more word: try to use combination of NavigationMesh nodes instead of NavigationSector + NavigationMesh as a workaround.

[ivan.cuevas]

I tried, but it didn't work :(

[unclebob]

Sorry for the late reply. Passed this issue too.

 

Thanks again, Iván! 

[unclebob]

Hi, Iván!

 

Sorry for necroposting (gold_shovel.jpg).

 

By talking with the dev team we've found that it was designed like so. You could still go with NavigationSectors and a bunch of Obstacle* nodes but I personally think it'll be much better to use third-party pathfinding code here and pass your navmeshes to that library.

[ivan.cuevas]

I see..., I think I'm going to start a search for a third party library. Any suggestion to use as a filter?

[unclebob]

I think this one is a good start (it's open source and has nice toolset): https://github.com/memononen/recastnavigation

[ivan.cuevas]

Thanks unclebob :)

[silent]

Maybe this plugin from Christian can be helpful in your case too: https://developer.unigine.com/forum/topic/3034-recastdetour-meets-unigine/

[ivan.cuevas]

Thanks Silent :)