Jump to content

how and when to use the Matrix decompose() api?


Recommended Posts


i get confused by the function Matrix decompose() api

in this tutorial https://doc.babylonjs.com/resources/frame_of_reference

i know  mesh  has its world matrix and its local frame of reference 

after apply some transform ( position,  rotate and scale)

 whenever we want to get the mesh`s world matrix

we can call 



and i see lots of people use decompose() function 

after i checking its usage 

i thought the decompose() is for decompose a matrix like the mesh world matrix 

to get how the mesh be transformed

that is to say

how a identuty matrix [ BABYLON.Matrix.Identity()]

be  position,  rotated and scaled

by using decompose(scale?: Vector3, rotation?: Quaternion, translation?: Vector3)

we can get those three components

am i right ?

till i see some people use it in this way

m.decompose(BABYLON.Vector3.Zero(), BABYLON.Quaternion.Identity(), position)

that make me confused

how can i set the components

the scale  set to BABYLON.Vector3.Zero()

the rotation set to BABYLON.Quaternion.Identity()

can some one tell me why?

and how the matrix decompose() exactly the correct usage



Link to comment
Share on other sites

Hello! decompose is used to break a matrix into 3 basics component (scaling, quaternion and translation). 

So if you have a mesh and you want to decompose the world matrix to get, let's say, the position you will call something like that:

var matrix = mesh.getWorldMatrix();
var position = BABYLON.Vector3.Zero();

matrix.decompose(null, null, position);

// position now contains the translation part of the matrix


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...