I built a guardrail that I want to place on both sides of a windy (!) street. The guardrails have to be rotated in order to follow the curves on that street. I dont' want to place each guard rail object manually, so I'd like to use an ecosystem. I've got a mask of the borders of the street that I use as a density map, I also checked "Avoid overlapping Instances" and "Force regular alignment of instances". The thing is that the guard rail instances don't follow the road, they're just placed next to each other with the same rotation. Does anyone have an idea on how to accomplish this?

If you ever find out how, please let me know. :-)
I already had several images that I wanted to make using this principle but never solved that problem.
It's fairly easy to make all instances of an eco to face a specific direction, like, for example, pointing to the center of an object, but to control the specific rotation of each one according to some external element or rule... that I never discovered how to do.

Hmmm...I expected a similar answer. To be honest I don't even have a clue how Vue would handle such a feature. I mean, the mask is a bitmap which consists of pixels and not of coordinates. I suppose you'd need at least a vector following your bitmap image (almost some kind of "overlay" between the two) so that you have some coordinates. That way you could probably create a function that drives the amount of rotation of a specific axis based on the vector coordinates.

Oh well, just a thought, but anyway I think i'd not be able to create such a function within the function editor.

Does it need to be 3d?  If you are not animating maybe the far away parts can be done as a texture with an alpha channel.  Take a pic from above of the road.  Take it into Photoshop or something.  Draw an outline of the road where you want the guardrail to go.  This will be made into a terrain in Vue.   Load the road outline into the terrain editor.  You will probably have to increase the scale.

Make the guardrail piece on a black background and save with an alpha channel.  Use this for the texture on the terrain.  You will have to play with the scale and position settings but I think you can get it to work.

Up close you could use some 3d guardrail.  

I have tried something similar but not exactly.  From watching many geekatplay.com tutorials, it seems like a good way.

Another posibility is to use replicate to place the pieces in their approximate locations and then move them into position.

 Good luck.

This is an awsome idea. The street can only be seen in the distance, s I don't need closeups anyway. I'll definitely try it and post the result. Scattering and replicating of the object did not work in that case, I already tried it.

Thanks again :-)