Some operators are working for multiple-object editing however are still not fully benefiting from it.
The most common case is that the operator works but only if all the objects have the same transformation matrix.
MESH_OT_select_similar(SIMEDGE_FACE_ANGLE, SIMFACE_AREA, SIMFACE_PERIMETER). rB0c1934f3c2d
- MESH_OT_knife_project and MESH_OT_knife_tool.
Need to convert the code from screen space to world space. More details on D3637.
- UV_OT_weld (UV_STRAIGHTEN, UV_STRAIGHTEN_X, UV_STRAIGHTEN_Y).
The current logic to determine the first and last selected vertex is not very compatible with multi-object. We should be able to select vertices from different objects, and use their position to determine the line extremes.
The axis need to be in world space, not local space.
Need to calculate direction taking scale into consideration.