creating a tree alley

I’ve now been struggeling with that for hours - and I’m afraid I need some help.

I have to create a nice leaf tree alley. So I imported 3 slightly different trees into blender (stl), which look like this:

My idea was to group them and then create an array of the group. When I border select all the “trees” and “leaves” and hit “ctrl-G”, exactly nothing happens. When hitting “alt-G”, they move all together to another place, but again I do not see any Group" instance in the outliner.

What am I doing wrong - or is wrong in my setting?


That’s not a tree alley, it’s a cropped screenshot of the outliner that hides every other bit of information outside it.

In it, the mesh type objects are parented, which is how they get the hierarchy. Groups in Blender are more abstract in that they’re a collection of objects. Groups can be listed in the outliner by switching its view mode to groups, and groups for one object are in object properties -> groups.

Ctrl+G creates a group. Alt+G resets the location (G - grab/move, alt+G - reset location). Grouping options are in 3D view object menu -> groups.

Group instances (shift+A -> group instances) are objects with group duplication enabled, which is one of the procedural duplication methods and uses actual object instancing.

Thanks for clarification of the group issue.

Obviously, I was not very clear in my request.
I need to create a alley of trees and could not find any tutorial or so.

So my idea was to import 3 slightly different trees, make them one “unit” and create an array of that unit - so the 3 trees are repeated but do not look as just one tree being repeated all the time.

Could anybody be so kind and give me a hint which is the tool to create such a “unit” out of 3 single trees?
Or point me to a “tree alley tutorial”?

Thanks a lot in advance,

This is, how I did it. Quite likely, there are better ways… (-;

  1. imported 3 different trees
  2. scaled them to the proper size, placed them into a row
  3. selected the “leaves” component of each, applied the “decimate” modifier (mulitplier 0,4)
  4. selected “wood” and “leaves”, both of each of the 3 trees (6 objects in total)
  5. joined them (ctrl-j) to make one object
  6. applied the “array” modifier, repeated 15 times, “relative offset”
  7. applied the “array” modifier again, repeated 2 times, offset in -Y direction to create the 2nd row

I guess this way is not very much optimized in relation to rendering time, but at least the file remains quite small.

Hope this may help anybody some day.


This way you have no variation in size, rotation and arrangement for the three trees all along, and you can easily see the pattern.

I would prefer a particle approach:
forming a group with the trees, you can get them to be emitted as hair by a ground invisible plane which you subdivided into two rows and several columns (a 2X15 quads in your case).
If you set hair to be emitted from faces, one from each, you can choose even the recursion of each tree (Use Count), and you can give them some random size and rotation.
The ground polygons can also be unconnected, BTW.