Three.js: Box3#applyMatrix4() no longer supports projection transformation matrices

[razh]

Description of the problem

13993 introduced an optimization to Box3#applyMatrix4() that only supports affine transforms.

CodePen

• geometry.applyMatrix() - The geometry is transformed with applyMatrix().
• r93 Box3#applyMatrix4() & r92 Box3#applyMatrix4() - A Box3 instance is constructed from the geometry. A non-affine matrix is then applied.

For BoxGeometry, it is expected is that both operations result in equivalent Box3 instances.

The r92 version transformed each Box3 vertex, then used setFromPoints() to resize to fit.

• r92: https://github.com/mrdoob/three.js/blob/r92/src/math/Box3.js#L562-L596
• r95: https://github.com/mrdoob/three.js/blob/r95/src/math/Box3.js#L562-L585

See https://github.com/mrdoob/three.js/issues/6039 for a similar issue with a Vector3#applyMatrix4() optimization.

Three.js version

• [x] Dev
• [x] r95
• [x] r94
• [x] r93

Browser

• [x] All of them

OS

• [x] All of them

[WestLangley]

@razh Thank you for providing a well-written and clear demo.

I support reverting #13993.

[Mugen87]

/cc @mikialex

[mikialex]

I haven't consider the case that matrix is not affined, for consistency it should be revert