TransformControls: fix some edge case transforms

[AlaricBaraou]

Related issue: #21840

Description

Unexpected transform happens when using TransformControls under theese three specific conditions:

• When the object has a rotated parent
• The coordinate space is set to 'world'
• TranslationSnap is a numeric value

Addiotionnaly if the scene had a rotation, it would also mess up the TransformControls expected behaviour.

Both have been fixed in this PR.

*note, changed a snap value in the demo that was wayy to high to be usable with translate

fixtransform.mp4

• closed the previous PR TransformControls: fix some edge case transforms #27718 after forgetting to remove a line

This contribution is funded by Alaric Baraou 🦦

[Mugen87]

I can confirm your PR fixes the issue but the approach isn't ideal, tbh. We need to find a solution without influencing how the world transformation matrix is computed.

If not, this will cause issues when we rethink the update matrix process and lifecycle in three.js and try to find a more optimized implementation. Ideally, components just request a world matrix and do not modify their computation.

In other words, TransformControls has to work with an unmodified version of the scene's transformation hierarchy. Fixing the controls in combination with rotated ancestor nodes has to be done in a way that the rotation is correctly taken into account and not ignored.

[AlaricBaraou]

Would this match your requirements ?

If we replace my block

// if TransformControls has a parent, set its local position to the inverse of the parent world in order to have a worldMatrix to identity
if ( this.parent ) {

			this._transformMatrixWorldInv.copy( this.parent.matrixWorld ).invert();
			this._transformMatrixWorldInv.decompose( this.position, this.rotation, this.scale );

}

super.updateMatrixWorld( true );

That way we don't influence how the world transformation matrix is computed, we just set the TransformControls local position.

[Mugen87]

That looks indeed better.

[AlaricBaraou]

Awesome!
I'll push that commit later today

[AlaricBaraou]

updated, it should be good now 👍