Cutting holes in navigationMeshes by code viable?

soloparatolos

Hi !

Im trying to overcome the lack of navigation mesh capability of "avoiding things" when creating procedural scenes. My idea was to have a basic mesh and erase the poligons on a radius from the object. The thing is that I erased the vertices from the mesh vertex array... but when trying to recreate a mesh with the new vertex array... the new mesh is a mess.

I guess that the index array needs to be tweaked too... but... there are a lot more index than vertex, which made me quite confused... (for some reason looks like the index position on the array are not corresponding to the order of the vertices....)

Could someone, knowing my goal, recommending an approach?

Thank you so much, Solo

Megalomaniak

I would use CSG for this, but having just googled it, there might be an issue with it.

Might be worth a try though, the issue report is from 2018 so maybe it has been fixed. Would ceertainly be the easiest way to go I'd imagine.

soloparatolos

Hi Megalomaniak.

I didn't knew that I could convert the CSG node stack in a "normal" mesh to use it afterwards in whatever I need. I have to check that after work.

Thank you for the sugestion!

Megalomaniak

So the issue I linked got a fix and has been closed, should the latest release not work out, it might be worth checking out a daily build.

soloparatolos

Hi Megalomaniak,

Yep, just compiled master and it's working. Now I just have to wrap my head around how to create a navigationMesh from an ArrayMesh.

Thank you so much for the help with the git issue.

TwistedTwigleg

@soloparatolos said: Now I just have to wrap my head around how to create a navigationMesh from an ArrayMesh.

One way you could create the Navigation mesh is using the create_from_mesh function and passing in the ArrayMesh. I don't know it it would work for sure, but I've used the create_from_mesh function with an ArrayMesh returned by the SurfaceTool and it seemed to work okay.

soloparatolos

Hi TwistedTwigleg,

@TwistedTwigleg said: One way you could create the Navigation mesh is using the create_from_mesh function and passing in the ArrayMesh. I don't know it it would work for sure, but I've used the create_from_mesh function with an ArrayMesh returned by the SurfaceTool and it seemed to work okay.

I checked the ArrayMesh I created from the CSGCombiner and it's fine... but for some reason when I try to create the NavigationMesh using "create_from_mesh()", the newNavMesh looks empty... Im probably doing something wrong here...

Any idea?

TwistedTwigleg

Looking at the code, I don't see anything that would be causing it not to work. I'll download a Godot 3.2 nightly build and see if I can get a example/prototype project working.

TwistedTwigleg

Okay, after a couple hours of testing, I have came to the conclusion that either one of two things are happening: Either the create_from_mesh function does not work, or the ArrayMesh returned by the CSG mesh does not work.

I was able to successfully generate CollisionShapes and StaticBody nodes from the returned CSG mesh, so I do not think the issue is in the ArrayMesh. Rather, I think the issue lies somewhere in the create_from_mesh function.

Unfortunately, I couldn't find any workarounds or solutions to the problem. There might be a way to do it, I have no idea what it is and tried almost everything I could think of with no results. Most of the time, it just fails silently and doesn't add anything to the Navmesh, vertices or otherwise.

Maybe this is a Godot bug?

Regardless, I have no idea why it is not working. Hopefully you will be able to find a solution.

soloparatolos

Sadly I couldn't find an alternative way to create a NavMesh having the ArrayMesh neither...Tomorrow I'll create a minimal project to report the bug in github.

Thank you so much for the time and effort to check this, I really appreciate it.

TwistedTwigleg

@soloparatolos said: Sadly I couldn't find an alternative way to create a NavMesh having the ArrayMesh neither...Tomorrow I'll create a minimal project to report the bug in github.

Sounds good. Hopefully whatever is causing the issue(s) can be fixed.

Thank you so much for the time and effort to check this, I really appreciate it.

No problem, I was curious and I like helping when/where I can! My apologizes that there doesn’t appear to currently be a solution.