How to apply a matrix transformation and set the result as default state in ThreeJS?

Question

I have a group of THREE.Mesh objects. My goal is to use something like group.applyMatrix( new THREE.Matrix4().makeRotationX( Math.PI / 2) );. Then, I would like to make the result as the group default matrix, so that I can use matrixUpdate() in my animation.

In ThreeJS docs, we can find: "Calling updateMatrix will clobber the manual changes made to the matrix, recalculating the matrix from position, scale, and so on."

Is there a way to make the manual changes I want and then set the result as if it was the default state of group?

create another Object3D on top of your structure and set the matrix there. — gaitat, Mar 21 '16 at 16:30
Related: http://stackoverflow.com/questions/27022160/three-js-can-i-apply-position-rotation-and-scale-to-the-geometry/27023024#27023024 — WestLangley, Mar 21 '16 at 16:58
@WestLangley In my case, I have a group of THREE.Mesh, not only one. How can I adapt for my case? — Bruno Lima, Mar 21 '16 at 17:37
@gaitat As I said, I do already have an Object3D on top of my structure, called "group". — Bruno Lima, Mar 21 '16 at 17:42

score 2 · Accepted Answer · edited May 23 '17 at 12:31

2

Based on @WestLangley related answer, here is the solution for my problem! After executing all the matrix transformations I want, I just needed to do:

group.children.forEach( function(mesh) {
    mesh.geometry.applyMatrix( group.matrix );
});
group.updateMatrix();

edited May 23 '17 at 12:31

Community

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answered Mar 22 '16 at 21:40

Bruno Lima

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This is updating the vertices of the geometry. Maybe what you want, instead, is `mesh.applyMatrix( group.matrix );`. – WestLangley Mar 22 '16 at 21:57
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@WestLangley I needed to update the geometry for my purposes... In this case, I wanted to correct the rotation of an object made of a group of meshes – Bruno Lima Mar 24 '16 at 14:47

How to apply a matrix transformation and set the result as default state in ThreeJS?

1 Answers1