[SOLVED]getPivotMatrix xyz local values

[DigiHz Data]

Well.....

To set the pivot matrix is easy:

mesh.setPivotMatrix(BABYLON.Matrix.Translation(-1, -1, -1));//this sets the pivot in xyz axis

But how do we get the pivot matrix xyz values from the mesh?

console.log(mesh.getPivotMatrix());//This gives me only the pivot matrix of the mesh.

How do i go from here to get the local xyz values of the mesh pivot matrix?

Note: What i am looking for is to be able to show the position of the pivot of the mesh.

Edited November 13, 2016 by DigiHz Data
Solved

[adam]

http://www.babylonjs-playground.com/#147HRL#1

http://www.babylonjs-playground.com/#147HRL#2

http://www.babylonjs-playground.com/#147HRL#3

[DigiHz Data]

@adam

Not exactly what i am looking for.

I want to get the pivot matrix xyz values from the mesh (local values). So that i can show a pseudo mesh for the pivot's position.

[adam]

 

[DigiHz Data]

i made a pg:

http://www.babylonjs-playground.com/#1ZK5I9#4

Look line 26-29.

However....When setting the pivot matrix, it also moves the mesh!

I not want to move the mesh,

Edit:

i know i can add a vector3 and parent it to the mesh and rotate/move the vector3, but is there no other easy way to do this?

I am working on a pg to illustrate, (trying to rotate a mesh with the pivot matrix changed without the need of a parent).

I be back here about this when i made my pg.

[JohnK]

Here is an example of a moving pivot not parented to a box. Not sure if it what you are actually looking for though.

http://www.babylonjs-playground.com/#29BGXO#4

[DigiHz Data]

@JohnK Not sure about this, but i am working on a PG so you all see what i mean and what i am looking for.

....Hold on until that.

[DigiHz Data]

The issue is like this....

When we use this line of code to change the pivot matrix...

mesh.setPivotMatrix(BABYLON.Matrix.Translation(x, y, z));

It moves the MESH to! (then we also have to reposition the mesh again)

And i am trying to find a solution for not moving the mesh itself by creating a new function that updates the pivot matrix but NOT move the mesh itself.

See PG:http://www.babylonjs-playground.com/#25TNA4

This PG works as intendeed as long as we not move, rotate or scale the mesh.(Have to implement code for this to!)

 

[DigiHz Data]

Adding rotation sliders to the PG.....http://www.babylonjs-playground.com/#25TNA4#1

Now things become wrong when the mesh is rotated.

How to fix this PG?

I think it has to do with local /world values, but i am not sure.

 

[JohnK]

How about this one

http://www.babylonjs-playground.com/#25TNA4#2

[DigiHz Data]

that seams to work perfectly. BUT....

i want the code in the function.

Can you update the code so that it works inside the function @JohnK?

PLZ

[adam]

I'm confused.  Can you tell me how that is different from the first PG I posted?

http://www.babylonjs-playground.com/#147HRL#1

[DigiHz Data]

1 minute ago, adam said:

I'm confused.  Can you tell me how that is different from the first PG I posted?

http://www.babylonjs-playground.com/#147HRL#1

The difference is that i want it to work in a function, so that we might add this function to BJS.

[DigiHz Data]

To make it clear to everyone....

Try make this work inside the function plz.

[adam]

1 minute ago, DigiHz Data said:

Try make this work inside the function plz.

I think you need to study some basic javascript coding.

 

[DigiHz Data]

Just now, adam said:

I think you need to study some basic javascript coding.

 

true, thats why i ask for help.

[JohnK]

IMHO the difference is that in your @adamPG if you move the small pivot sphere then the large orbiting sphere moves relative to the pivot, the orbit is the same just everything has been repositioned. What I think DigiHz Data wanted and what happens in the two PGs I linked in this topic if you move the pivot then the orbit changes, the orbiting mesh still passes through the position it was at when the pivot was moved.

[adam]

http://eloquentjavascript.net/03_functions.html

[DigiHz Data]

Exactly. i want the mesh to not "reposition" even if we update the pivot matrix.

Visually the mesh looks as it's in the same place all the time when we move the pivot matrix.

[DigiHz Data]

@JohnK

http://www.babylonjs-playground.com/#25TNA4#2  not work perfetcly.

still see the red mesh jumping around when changing values. but hey.....thank you for trying.

[JohnK]

Giving you a function is not straight forward. Your function updateMeshPivotPosition is no longer needed since you no longer need to mesh with the mesh and using the GUI updates the position of the pivot. If you replace the three similar bits of code for rotation it is easy to produce a function that has mesh and axis as parameters and makes use of the given code. But this will only do rotation if you need a more general function for scaling etc then you need to first check out scaling

to see how you are going to handle scaling.

IMHO you could put what I have done into a function if you wish but you need to decide what you want the function to do first.

[JohnK]

11 minutes ago, DigiHz Data said:

@JohnK

http://www.babylonjs-playground.com/#25TNA4#2  not work perfetcly.

still see the red mesh jumping around when changing values. but hey.....thank you for trying.

What?????? in my browser the red mesh stays perfectly still when moving the pivot and rotates around the pivot when the angles are changed. Now I am confused as to what you want.

[DigiHz Data]

Yes i know that it is not straight forward, (then it would allready be in BJS )

I try to be clear what i am looking for....

When we use setPivotMatrix , then it reposition the mesh and we have to position the mesh again to put it where it originally was.

What i am trying to archive is a new function for BJS that updates the pivot matrix WITHOUT changing the mesh position visiually, the cordinates are changed ofcourse.(So that we do NOT have to move the mesh manually after we call setPivotMatrix.)

 

[DigiHz Data]

7 minutes ago, JohnK said:

What?????? in my browser the red mesh stays perfectly still when moving the pivot and rotates around the pivot when the angles are changed. Now I am confused as to what you want.

 

7 minutes ago, JohnK said:

What?????? in my browser the red mesh stays perfectly still when moving the pivot and rotates around the pivot when the angles are changed. Now I am confused as to what you want.

if you rotate in 1 axis and then rotate in another axis you see the jump.

[DigiHz Data]

And in the top of my PG's it say's:

/*Moving the pivot point on a mesh without the need of a parent*/
/* (whithout moving the mesh itself)*/
/*(Taking into account move,scale and rotation)*/

/*The green sphere is the pseudo pivot point*/
/*(not parent to the red mesh and is only here for showing where the pivot is)*/

/*The red box is the mesh we are affecting*/

/*This is a function that may be implemnted in BJS ?*/
/*this function is called when we move our pseudo pivot*/

 

Anyone not read that?