These were `uint3` before, but they should just be `int3`s. Also uses `array_utils::copy_group_to_group` with new cpptype `int3`. Pull Request: https://projects.blender.org/blender/blender/pulls/129166
These were `uint3` before, but they should just be `int3`s. Also uses `array_utils::copy_group_to_group` with new cpptype `int3`. Pull Request: https://projects.blender.org/blender/blender/pulls/129166