1. create rail way steps with two curves mode(note:the two curves must has each own shapes, not the instance curve! the original obj direction is based positive X,and the pivot is the min x,and freezed transform) 2. create cam path curve and cam up constrain curves based two rail curves
3. just placed objs along single curve(single curve mode,note: in this mode ,the original obj direction is based positive Y,and the pivot is min y,and freezed transform)
4. based particle instance ,bake particle instance to geo
5. the nearestPointOnCurveCmd_maya2013_x64.mll is just get the closest point form nurbs curve or nurbs surface based the given point positionuse as this:eg: vector $pos = `nearestNurbsPos -p $givenPos.x $givenPos.y $givenPos.z -tcn "curveName_or_nurbsName";
6. if the curve list has more than two curves, the first two curve will be used.
1. copy the script file *.mel to C:\Users\hq\Documents\maya\2012-x64\scripts
2. copy the plugin file *.mll to your plug-ins path,
3. run the mel cmd: "railWay" in script edit to start the railWay UI,you can save it to shelf.