solved NULL ENGINE behaviour using setPivotPoint and CSG

[Arte]

Hi All,

I have strange behaviour in NullEngine using setPivotPoint with CSG

Same Code, different results?

(Blue background in Playground, grey background NULL ENGINE)

https://www.babylonjs-playground.com/#8PIKRZ

@Deltakosh do you have any idea?

Thank you in advance.

 

[Guest]

wait..how do you get render from NullEngine?

[Arte]

Logic on server side, render on client side.

[Guest]

woot  This is kind of interesting use! Can you provide a repro? This should work as CSG is pure javascript code

[trevordev]

If you are performing logic on the server side and passing only data such as position to the client you might run into errors because the way the pivot works, changing the pivot may not update the position. I would recommend using a parent object instead of the pivot, see first paragraph here https://doc.babylonjs.com/how_to/pivots and this PG: https://www.babylonjs-playground.com/#GH4N1R#1

[Arte]

38 minutes ago, trevordev said:

If you are performing logic on the server side and passing only data such as position to the client you might run into errors because the way the pivot works, changing the pivot may not update the position. I would recommend using a parent object instead of the pivot, see first paragraph here https://doc.babylonjs.com/how_to/pivots and this PG: https://www.babylonjs-playground.com/#GH4N1R#1

That's exactly what's happening now. I like what you suggested, but. I think NullEngine should mach client side .

[trevordev]

My guess is they are the same in data. Like if you print out the positions, they should be the same if the logic was done in the exact same order in the client vs the server's null engine. If you have a repro where numbers printed out by null vs non-null engine are different please do share.

[Arte]

I'm using same code from https://www.babylonjs-playground.com/#8PIKRZ (for NullEngine and Client Side). This is happening if I'm using CSG. I think BABYLON.CSG.FromMesh creating a problem (loosing information about pivot). I'm not that clever to check it . 

[Arte]

1 hour ago, trevordev said:

My guess is they are the same in data. Like if you print out the positions, they should be the same if the logic was done in the exact same order in the client vs the server's null engine. If you have a repro where numbers printed out by null vs non-null engine are different please do share.

All numbers a same.

[Guest]

So all numbers are the same but you still get different positioning? 

[Arte]

Ooo yes 

[Guest]

this looooks suspicious  Are you sure of your code?

[Arte]

100%

Same as in PlayGround

///////////////////////////////

// CODE FROM NULL ENGINE

var parent = BABYLON.MeshBuilder.CreateBox("Parent", {height: 3.2, width: 2.2, depth: 1.2,sideOrientation: BABYLON.Mesh.DOUBLESIDE}, scene);

var mat = new BABYLON.StandardMaterial("material", scene);

mat.alpha = 0.3;

parent.material = mat;

 

var part = BABYLON.MeshBuilder.CreateBox("Part", {height: 3, width: 2, depth: 1,sideOrientation: BABYLON.Mesh.DOUBLESIDE}, scene);

 

part.setPivotPoint(new BABYLON.Vector3(0,1,0));

part.position.x = 1;

// part.rotation.x = -1;

part.parent = parent;

 

var tool = BABYLON.MeshBuilder.CreateBox("Tool", {height: 1, width: 2, depth: 2,sideOrientation: BABYLON.Mesh.DOUBLESIDE}, scene);

tool.material = mat;

tool.setPivotPoint(new BABYLON.Vector3(5,-1,0));

tool.position.x = 1;

tool.rotation.x = -1;

// tool.parent = parent;

 

var partCSG = BABYLON.CSG.FromMesh(part);

var toolCSG = BABYLON.CSG.FromMesh(tool);

var newPartCSG = partCSG.subtract(toolCSG);

 

var newPart = newPartCSG.toMesh("csg", part.material, scene);

 

// tool.dispose();

part.dispose();

// CODE FROM NULL ENGINE

///////////////////////////////

[Guest]

OK can you repro on a page with the NullEngine (using Babylon.max.js) I will try to debug it.

Also (I am traveling and I don't have too much free time this week), perhaps you could try to do a per mesh comparison between engine and NullEngine regarding properties like world matrix (is this matrix the same on all meshes between both engine)

 

Can you also try to force a mesh.computeWorldMatrix(true) on all meshes before doing csg?

[Guest]

Also how do you render on client side when using NullEngine? Are you sure your local renderer interpret the pivot like Babylon.js?

[Arte]

40 minutes ago, Deltakosh said:

OK can you repro on a page with the NullEngine (using Babylon.max.js) I will try to debug it.

Also (I am traveling and I don't have too much free time this week), perhaps you could try to do a per mesh comparison between engine and NullEngine regarding properties like world matrix (is this matrix the same on all meshes between both engine)

 

Can you also try to force a mesh.computeWorldMatrix(true) on all meshes before doing csg?

Okay

 

38 minutes ago, Deltakosh said:

Also how do you render on client side when using NullEngine? Are you sure your local renderer interpret the pivot like Babylon.js?

I'm creating everything on server side and passing data through assetsManager.addMeshTask. Does that make sense?

 

Thank you for your time. 

[Arte]

@Deltakosh 

Shared files:

index.html // create and download (serialised scene)

serializedScene.json // downloaded json file (serialised scene)

Loader.html // load serialised scene

https://github.com/Gal-Arte/BabylonTest/tree/master/NULL ENGINE using setPivotPoint and CSG

Playground to compare https://www.babylonjs-playground.com/#8PIKRZ#1

Lets hope for the best 

[Guest]

Can I ask you something else? Can you serialized the scene from a regular PG and reload it?

I'm pretty sure this comes from the serializer which does not take the pivot correctly in account

[Arte]

@Deltakosh Regular PG results

Serializer!!!

[Guest]

Ok so I think I can fix it  Can you share the PG where you serialized and reload it? I will use it to fix the serializer

[Arte]

https://www.babylonjs-playground.com/#8PIKRZ#2

If you comment out line 55. Original part position - Out.

Or comment out lines 67-79, to see original view.

[Guest]

Fixed: https://github.com/BabylonJS/Babylon.js/commit/1e37e3b9d1c7cb5e6eb8a63557b278e65f0d393b

[Arte]

Now I can go-ahead with my project "Parametric Cabinet". Thank you and ?.

[Guest]

Good luck

[Arte]

@Deltakosh

I updated npm babylonjs "Babylon.js null engine (v3.3.0)" , but for some reason I have same results as before. On PG is working perfect. ?

***EDITED***

I tried what @trevordev suggested "I would recommend using a parent object instead of the pivot" 

Results: https://www.babylonjs-playground.com/#8PIKRZ#3

BABYLON.CSG ignoring not just pivot but parenting as well???

My bad. I forgot sphere.computeWorldMatrix(true);

https://www.babylonjs-playground.com/#8PIKRZ#4

 

But npm babylonjs still issue.