By collection instances do you mean you instance the collection multiple times (one instance for each branch) and then place the instances manually on the tree ? or did you use something like animation nodes for the placement ?
Atm, there is no automatic solution to plug leafs to twigs or twigs to brances that way. I did not use animation nodes, instead I placed instances manually.
For a collection, only a single collection instance per sub-branch collection is used. All other instances in the collection are ‘dupli linked’ instances.
Needed some distance. This workarounding distracts too much from things that really matter.
I distanced from Blender and Computer, and drew some some ideas. Its much more relaxing. And head does not feel like a brick with ears.
river erosion based canyon
Atm, I do not know working free solution for animated trees for Blender, except sapling.
Animated landscape test.
I tried to get rendertime per frame below 1 minute.
With lossless compression, there is some noise in the trees. Its aliasing, which does not occour in standalone images. If encoded, aliasing got fixed to some degree.
( Next time I try motion blur to fix frame-based aliasing. )
This time I discovered another way to simplify massive forest details. It was below my nose, I did not see.
Properties // Particles // Viewport Display // Amount
I set amount to 5%. With this option (and BoundingBox), there is no need for Child Particles to simplify viewport and keep Blender fluid.
Other project ongoing.
Part of my workflow to create sculpt brushes relies on rendering and OSL.
This time, I also considered volumetrics.
Workflow is …
render volumetric, density controlled with OSL Textures.
Render result is a grey scale image. This image is used as brush or displacement map.
This is not crafted terrain, displaced with image generated from volumetric rendering.