@tig said:
If you make the top and bottom 'tread' lines into 'curves' with ' weld.rb
' [divide the 1 edge into 2 or more pieces first], and also make 'curves' from the two side 'stringers', then you can use my ExtrudeEdgesByRails
[part of the Extrusion Toolset
] - then you'd pick the bottom 'tread' as the 'profile', then the stringers as the two 'rails' and finally the the top 'tread' as the 'melding-profile'... It should form a mesh face to suit... Here's a quick example...[attachment=1:3wyvaxf0]<!-- ia1 -->Capture.PNG<!-- ia1 -->[/attachment:3wyvaxf0]
thank you tigger, ill try it 
here is sample
