How to check object type

[MarianG]

Hi guys. I have an idiot question, and I have no idea how to deal with it
I have a scene where I create meshes, disc or plane like

if(this.metadata.isCircle == true)
	layer = BABYLON.MeshBuilder.CreateDisc("disc", {radius: this.metadata.radius, tessellation: 64, sideOrientation: BABYLON.Mesh.DOUBLESIDE}, this.scene);
else	
	layer = BABYLON.MeshBuilder.CreatePlane("plane", {height: this.metadata.depth, width: this.metadata.width, sideOrientation: BABYLON.Mesh.DOUBLESIDE}, this.scene);

After that I export them and use in other scene.
How to check on the other scene if loaded mesh is a disc or a plane?
1. I export them as babylonjs file, add a metadata something like "isCircle" and on load check metadata, great! - no problems.

2. I export them as obj file, here comes the problem. As obj doesn't keep the name, doesn't keep the metadata, so I have to check myself someway if loaded mesh is a disc or a plane.
Is there something internal to know if loaded/created mesh (basic elements) is a disc, a plane, a box, or etc?
 

[Wingnut]

Hi MG!  Not idiot AT ALL.  Really, a darned good question.

Obj format doesn't keep mesh name?  Are you sure? 

https://en.wikipedia.org/wiki/Wavefront_.obj_file

Named objects and polygon groups are specified via the following tags.

o [object name]
  ...
  g [group name]
  ...

I don't know what you are exporting to/from (what creates the .obj file)... but I think you are being cheated, somehow. 

Sometimes... all a mesh HAS... is its good name. 

Can you tell us more about this name-excluding .obj exporter?  Who built that thing?  Do we need to have a little talk with someone?  heh

[MarianG]

I'm using babylonjs objExporter.

But you give me an idea.

I found where it override mesh name, and I modified it to take the name from mesh, by default it change meshes name
https://github.com/BabylonJS/Babylon.js/blob/5b36a24a55f5f572d0e28d3a7b1c9c521dc6701f/dist/serializers/babylonjs.serializers.js#LC38
It works well. Thanks @Wingnut.

Another question regarding on this. Why on import I get 2 different meshes foreach mesh? I mean I save an array with 5 meshes as obj, and when I import it in the other scene I have 10 meshes in the succes function?

[Wingnut]

Good find, MG!

Exported .obj file, when examined, shows 5 mesh?

[MarianG]

@Wingnut you are "grande".
Thanks to your previous post I found the answer to the second question too. 
Again, by default, the exporter create a group and a object foreach mesh that you want to export, I just comment 

output.push("g object" + j);

from exporter and I have only my meshes.
And I modified export.mtl to support material foreach mesh in the same mtl file, by default it create different mtl foreach mesh. 

Btw, I see these minor changes usefull, maybe they can be used by default on exporter, and a few flags like "useGroup" for group meshes and "useSameMtl" for using the same mtl for all meshes.