https://github.com/mrdoob/three.js/wiki/Migration-Guide#r127--r128
https://github.com/mrdoob/three.js/milestone/41?closed=1
- Global
- More usage of ES6 features. #21546, #21622, #21623, #21624, #21625, #20016, #21628, #21635, #21643, #21646, #21648, #21662 (@linbingquan, @Mugen87, @ianpurvis, @john-keith)
 - Add 
build-examplesscript. #21584, #21587, #21588, #21591, #21677 (@marcofugaro, @gkjohnson) - Remove more deprecated methods to improve tree-shaking. #21649 (@marcofugaro)
 - Improve ES6 toolchain. #21650, #21657, #21678 (@marcofugaro)
 - Rename 
test-lintnpm script tolint. #21652 (@marcofugaro) 
 - Color
 - DataTexture2DArray/3D
 - Helpers
 - Material
 - MathUtils
- Refactor code to allow for tree-shaking. #21651, a7b8ed2 (@marcofugaro, @mrdoob)
 
 - WebGLRenderer
 - WebGLTexture
 - WebXRController
 - WebXRManager
- Get linear/angular velocity for targetRay and grip poses if available. #21524, b82d7bd (@davehill00, @mrdoob)
 
 - XRHandPrimitiveModel
 
Documentation
- Improved 
SkinnedMeshpage. #21561 (@prominentdetail) - Improved 
TrackballControlspage. #21703 (@mrdoob) - Improved 
WebGLRendererpage. #21637 (@yomboprime) - Added 
five-serverto the docs. #21550 (@yandeu) 
Examples
- Clean up. #21552, #21566, #21664, #21671, #21684, #21688, #21704, 96971a6, 1912046 (@Mugen87, @marcofugaro, @mrdoob)
 - Convert codebase to ES6. #21563, #21583, #21585, #21586, #21589, #21592, #21593, #21597, #21596, #21598, #21599, #21600, #21601, #21604, #21605, #21611, #21610, #21612, #21614, #21616, #21618, #21619, #21621, #21620, #21629, #21632, #21630, #21645, #21644, #21653, #21658, #21660, #21680 (@Mugen87, @yomboprime, @tentone, @fraguada)
 - Fix param 
use2DLutinwebgl_postprocessing_3dlutexample. #21613 (@kchapelier) - Removed 
XLoader. #21617 (@Mugen87) - Mark certain event listeners in controls as non-passive. #21642 (@puxiao, @WestLangley)
 - Removed 
onmousewheelattribute inindex.html. #21647 (@puxiao) - Update 
fflateversion. #21669 (@gkjohnson) - Convert 
jsmfiles to use barethreeimport before npm publish. #21654 (@gkjohnson) - Refactor 
Skyusage. #21681, #21575 (@Mugen87, @sirxemic) - Fix 
webgl_gpgpu_birdsreferences error. #20675 (@gonnavis) - Bring 
dat.guiinside VR. #21700 (@mrdoob) - Use 
RoomEnvironmentinwebgl_animation_keyframesexample. fe12f87 (@mrdoob) - Use 
allow=""attribute in<iframe>. e041a2f (@mrdoob) - Removed 
#webxr-handsflag message. 5ed5390 (@mrdoob) 
- 
AmmoPhysics
 - 
GLTFLoader
- Fix incorrect boundingBox for normalized attributes. #21554 (@donmccurdy)
 - Add 
createNodeMesh()hook. #21458 (@takahirox) 
 - 
IFCLoader
 - 
KTX2Loader
- Update 
ktx-parsedependency, import enums. #21567 (@donmccurdy) 
 - Update 
 - 
NodeMaterial
 - 
OBB
 - 
SSRPass
 - 
VRMLLoader
 - 
WebGPURenderer
 
Editor
- Use class syntax in 
ViewHelper. #21631 (@Mugen87) - Remove the default color value of 
SpotLightHelper. #21675 (@1993heqiang) - Fix equirect backgrounds. #21690 (@Mugen87)
 - Use 
networkFirstinsw.js. 0b608ec (@mrdoob) - Only display video renderer when 
SharedArrayBufferis available. 71ffae3 (@mrdoob) Signalclean up. 0f418c7 (@mrdoob)- Save renderer changes automatically. 7c3d2f4 (@mrdoob)
 - Empty project title on clear. e07eca4 (@mrdoob)