maint: Add 'extern' to sms_3d_field declaration
maint: Add 'extern' to sms_3d_field declaration

JoppyFurr/Snepulator,JoppyFurr/Snepulator,JoppyFurr/Snepulator,JoppyFurr/Snepulator,JoppyFurr/Snepulator,JoppyFurr/Snepulator