Moving two objects to the same position. PivotMatrix problem

[PierreDuc]

This is a problem which I've been struggling for too long now. Probably my approach is completely wrong, and my knowledge of matrices are lacking.

Scenario:

• Two parent meshes in a scene
• Each parent has one so called connector mesh as a child
• Both parents have a pivotMatrix which is not equal to Matrix.Identity()
• Both child connectors have a pivotMatrix which is not equal to Matrix.Identity()

Problem

Moving the second parent in such a way that both child connectors have the same global position. Unfortunately this does not come out okay, because the pivotMatrix is 'messing' things up.

What have I tried

The models are made using 3DS Max and then exported to .babylon. When I apply a ResetXForm within 3DS Max on the connectors it all works fine, and the models connect at the right position. Unfortunately I do not have the possibility to do this for all the models I have.

I've tried using this piece of code (TypeScript):

let subject: BABYLON.Mesh = <BABYLON.Mesh>con2.parent;
let con1pos: BABYLON.Vector3 = con1.getAbsolutePosition();
let con2pos: BABYLON.Vector3 = con2.getAbsolutePosition();
let pos2: BABYLON.Vector3 = subject.getAbsolutePosition();

subject.setAbsolutePosition(pos2.add(con1pos.subtract(con2pos)));

What I would really like is a way to make the pivotMatrix == Matrix.Identity() and have the mesh/geometry stay at the same position. Because before I can move these, I also need to rotate the subject, in such a way that con2 faces the exact opposite direction as con1. And I am pretty sure that the pivotMatrix is going to mess up that as well.

Edit:

I've created two playgrounds. 

http://www.babylonjs-playground.com/#1UMJXS#0 (3ds max export where the connectors have an altered pivot)

http://www.babylonjs-playground.com/#1UMJXS#1 (3ds max export where the connectors are reset using resetXform)

I was very convinced that I did get values using the getPivotMatrix() method, but checking today, I was horribly wrong. Apparently that data is not output by the babylon 3ds max exporter. Which gives me the feeling there is little I can do about it. Perhaps the exporter needs to be adjusted so that the adjusted pivot matrix gets exported as well

 

 

 

 

Edited September 1, 2016 by PierreDuc

[jellix]

I don't know exactly what you want to achieve.

You want to turn the subject opposite to the second parent and then place the subject to a position where the children get the same position, right?

So what happens by using your current code?

[GameMonetize]

Hello, to be more efficient to help you we need a repro in the Playground

[PierreDuc]

10 hours ago, Deltakosh said:

Hello, to be more efficient to help you we need a repro in the Playground

I've updated my question, but i seem to have hit a deadend, considering the pivot values do not get exported from 3ds max to babylon

[GameMonetize]

Correct, pivot is integrated into world matrix but not exported separately.

 

You can still export your meshes from 3dsmax and then setup pivot manually with mesh.setPivotMatrix()