Itoo Software Forum

Author Topic: Drop curb problem on curved line  (Read 1728 times)


  • Newbie
  • *
  • Posts: 46
Drop curb problem on curved line
« on: August 14, 2015, 02:10:04 PM »
When I try to use a drop curb on a curved line I get a weird overlapping mess.

Please see the attached railclone pro / max 2015 file and an image to illustrate the problem.

Paul Roberts

  • iToo Software
  • Hero Member
  • *****
  • Posts: 1762
Re: Drop curb problem on curved line
« Reply #1 on: August 14, 2015, 05:03:00 PM »

Unfortunately this is a limitation when using the Generator > Limit to ID feature on curved splines. Internally each spline section is considered separate so it cannot compute the curves required to create a continuous deformation where the two IDs adjoin.

However, with a little work it is possible to recreate the style using a different technique that doesn't use this feature.

In this approach we can use  the Conditional node instead of limit by IDs to detect the ID of the spline segment and add the relevant segments only to the appropriate spline sections. In order for this to work all the vertices within a spline section with the same ID should be either curve or bezier, with corner or bezier-corner reserved to mark a material ID change. You will also find using this technique that evenly mode does not work well, in fact I've removed it in the example, which can result in some alignment issues. Also you can no longer use the Start/End inputs to add the ramps at the beginning of the drop curbs so I've recreated it with composed and conditional corners, but it is a little trickier.

If I find another way to achieve this I'll post it here.

Many thanks,

Paul Roberts
iToo Software


  • Newbie
  • *
  • Posts: 46
Re: Drop curb problem on curved line
« Reply #2 on: August 14, 2015, 07:33:58 PM »
Much appreciated.

To be honest - I'm a user who mostly uses railclone for the ease of use of the presets - perhaps occasionally making some basic presets myself.

Last year you guys asked what extra presets you could all start adding to railclone - and my answer was to improve the ones that already exist.
I'm really glad that this issue is solveable - but also sad that my knowledge is far too basic to really even understand the solution you suggested - though I have gratefully downloaded and implemented your solution!

I wonder if the next step for railclone and forestpack is to keep overhauling these presets and give us versions like "drop kerb for curves, see limitations" or "drop kerb for straight roads" etc.

I also gather there are problems with the way you can store edging details in forest pack - I just wonder if choosing presets from within the plugin might star to give way to downloadable example setups?

Like a page with a database of common problems and common solutions - then we can download and tailor them!