After struggle with particles animation rotations, I decided to abandon particles.
Still using arrows instead of trees.
On animation nodes, I have to switch off “Auto Execution” in the ‘t’ tab, to prevent Blender from freezing.
To update whole Bunch, I hit “Execute Node Tree”
Thats how node tree looks like.
It almost replicates DupliFaces.
Now, look at instance count. 10000 instances. For a large scale forest, I would use around 100 times more instances. It took nearly 20 seconds to execute (19.28s, only single core used).
For large scale forest: this time, multiplied at least by 100. Around 30 minutes to execute node tree for a forest of just arrows.
Plane got more subdivisions.
Now, it seems there needs to be care about the Outliner. If “Animation Nodes Object Container” is opened, it slows down everything by a magnitude!
On 10000 instances, its 1.71 seconds if “Animation … Container” closed. If tis collection is open in outliner, 10000 instances take 18 seconds.
Trying 50000 instances. “Animation … Container” closed in outliner.
Blender freezes if I start “Executie Node Tree”.