Everything disappears if mesh is cloned and instanced

[Stalker]

Hi!

 

I'm trying to create various units for different players, each player can have multiple units, all from the same model.

Because materials can't be per instance, only per mesh (WebGL limitation if I know correctly), I create a clone of a model for each player, change the material and afterwards I'm doing instancing from those clones.

 

My problem is, that when I do this everything disappears (first it flickers and completely blank scene afterwards). Everything is visible again if bounding boxes are turned back on, but instances from clones aren't shown, only bounding boxes are at correct locations (attached first image). What am I doing wrong that this happens or is a bug?

 

A minimal example on plunkr: http://plnkr.co/edit/yOaBtmu9NaOQpoULo6pv?p=preview

 

EDIT: Example uses BJS version 2.2, but 2.3 suffers for the same problem.

EDIT2: Added second image that renders exactly the same scene, the only difference is checked option for bounding boxed in debug layer.

[BitOfGold]

Does the instance disappear when the mesh is out of the frustrum?
(I think the frustrum check is made per mesh and not per instances.)

[Stalker]

Instance checking is per frustum I believe.

And the problem is a little beyond just mesh and instance, because everything (also ground and other completely unrelated things) are missing . I attached an image to original post, where exact scene is rendered with bounding boxes on and off. 

[RaananW]

The problem is the fact that you are reusing the material in both clones (running clone doesn't clone the material as well).

Here is a working example : http://plnkr.co/edit/ytaLCOSNtECGaHm4UMXY?p=preview

[Stalker]

Thanks a lot! I blindly believed that clone clones entire structure.
Is there any simple way of creating deep clone for material (including all submaterials)? Or is a loop the way?

[Temechon]

You can use material.clone("newmat") : http://doc.babylonjs.com/classes/2.2/MultiMaterial#clone-name-rarr-multimaterial-classes-2-2-multimaterial-

However, it won't clone all submaterial. Maybe this could be added easily in the engine. I'll think about it.

 

Edit: I added a new parameter in MultiMaterial.clone (waiting for approval). You will be able to use it in the next nightly build.

Basically, you can use it like this: 

myMultiMaterial.clone("newname", true);

This will clone the multimaterial and also clone all of its submaterials.

[Stalker]

Instead of waiting I created the build myself and it works !

 

Thanks a lot!

[Swiftwork]

Hi and excuse me for necroing an old post, however I seem to be facing a similar issue and the suggested solution seems ineffective for me. Only the last cloned mesh is able to create instances.

Here is a playground demonstrating the issue http://babylonjs-playground.com/#29SZC0#6 (try removing the 3rd instance)

I hope it isn't just my naivety that is the problem

Regards Swiftwork

[GameMonetize]

Hello

this is because clones are sharing the same geometry (for performance reasons)

But in your case you do not want that as you are using instances with clones.

so simple fix: http://babylonjs-playground.com/#29SZC0#7

[Swiftwork]

It's always the simple things that get me, thank you for your aid @Deltakosh. Guess this necro will serve as a reference for others that face the same issue in the future!

[Swiftwork]

I jumped the gun a little, It seems as if the mesh loses its multimaterial or uv mapping if makeGeometryUnique() is called. Is this intended? Can it be avoided? I am trying to achieve a "carbon copy" of the original mesh with all preferences intact as sort of a base for future instancing.

Edit:

I don't fully understand what I am doing yet but it seem as if the issue with mulitmaterials can be solved by re-referencing or copying the original model's subMeshes, which appears to be have been lost or removed when makeGeometryUnique() is called.
http://babylonjs-playground.com/#29SZC0#8

Edited September 14, 2016 by Swiftwork
Solved issue by adding clone.subMeshes = original.subMeshes

[GameMonetize]

yep you found the issue  making a mesh unique resets its state