In our current array modifier we can have a cap. an end and repeating body. What is I want to make alternating insertions in repeating parts? maybe just another material or different geo in certain position? Driven by some condition , or nearby objects maybe ?
There may be more efficient ways to do this, but you can use the vertex index of a given mesh to control the instance object, at least in version 3.0 alpha:
Thanks rigoletto .but i can’t make them follow the curve that way.
Anyway Initially I mean something like array modifier that deform and merge repeating things together . I just need an alternating parts with different material and shap. An armco rail for example with a few rusted and deformed sections.
Anything I am trying with geo nodes ends up without materials
You can use multiple objects with multiple array modifiers and use proper spacing with them. You can then use drivers to tie the values proportionally. If you want more advanced stuff you will need to use Geometry Nodes or Animation nodes or Sverchok.