https://extensions.blender.org/add-ons/smear/

SMEAR is a 3D animation stylization Blender add-on, aimed at creation and customization of smear frames such as elongated in-betweens, multiple in-betweens and motion lines. The system is developed as part of the MoStyle ANR Project by Jean Basset, Pierre Bénard and Pascal Barla. It is described in the following publication: SMEAR: Stylized Motion Exaggeration with ARt-direction. Jean Basset, Pierre Bénard, Pascal Barla. Siggraph 2024 Conference Papers.