Persistent power

Probably the biggest change in this release has a profound impact on how your trees grow. In short: the vigor of a branch is now corrected to last year’s growth. When a branch has barely grown in length, it has less leaf area, and this means that there is less energy to grow buds for the next generation of branches. This makes it much harder for a new side shoot to become a strong lead branch. To escape the initial suppression imposed by their leader, only the most successful and brightest branches will survive the cut.

The improvement made in this area makes it much easier to tweak parameters, you feel in control. Parameters react the way you expect them to, and it’s much easier to create extreme shapes like slender trees and conifers.

Best of all, this change has proven several of my earlier theories wrong and greatly simplifies things. The Favor Bright (previously Favor Healthy) parameter is now much simpler, whereas before it was a complex mixture of two different effects. And the Inefficiency parameter is now completely gone! I never was happy with this one, but we just couldn’t get the desired conifers without it. Well now we can!

Easy Tweaking

Finally parameters like Favor End and Favor Bright react just the way you think they would. I’ve tried to summarize their effect in just two paragraphs:

Imagine a tree’s twigs as thousands of individual plants. The bright grow big, the dark they die – this is Favor Bright at its fullest. Now connect the plants with branches – give them a way to share their gains. When sugar flows freely and light is plenty, even shaded plants will get the support they need to grow on in the search for new light.

Favor End gives branch ends a head start over new side branches. It creates shorter, less powerful side twigs to start with, but a head start is not always a guaranteed win. Favor Bright takes over and will slowly turn the odds in favor of the best performers – to allow short side twigs to catch up or even take over as the new lead branch. Favor Bright and Favor End are two of the most important characteristics of a tree. They work together to create a wide spectrum of shapes and characters.

That’s the gist of it, but I’m working on a new article on how trees grow, to sum up all the theories behind The Grove. Coming soon!

Improved Bend

Something that’s been on my mind for some time is how bending branch ends was very hard to incorporate in presets. Through the years this bending’s influence was extreme, and only tiny bits of it could be used. Though when looking at real trees, this effect can be seen much stronger.

Bake Bend is now called Solidify to avoid confusion with the way the term baking is used in computer graphics. But its not just the name that has improved – there are now two separate solidify parameters – one for branch weight and one for the weight at branch ends. The theory behind this is that the solidifying of branches does not necessarily happen when the branch carries the most weight. Some trees carry big flowers in spring, others carry fruit in summer.

Replacing the previous calculations, solidify now uses the same high quality formulas used for regular bending. This increases the quality of solidify a lot and the improvements can be seen in all tree shapes. Most prominently in the weeping willow, and with it every weeping tree, which were a notoriously hard nut to crack. With these improvements they became a breeze. Try growing the new weeping willow preset to see for yourself.

Fork

There’s this small maple species growing in my brother’s garden, it’s a paperbark maple. Its small size makes it easy to study, and what a peculiar tree it is. Apart from its red flaky bark, its unusual leaf shape and its whorls of side branches, it also has crazy big branching angles. Side branches are almost perpendicular to their lead branch. But when looking at the trunk, it splits up several times to form a number of equally powerful main branches – and the strange thing is that these splits occur at a much smaller angle.

A split like this is commonly known as a fork, and it adds a lot of interest to the tree by creating a bifurcating structure, rather than a single main trunk. The reason why these forks are forming and why they split at a much lower angle was a mystery to me. But this small tree had two clues that made me form a theory:

It only seems to happen on powerful main branches, not on side growth. These powerful branches seemed to develop a large number of buds at the ends.

Clue number 1 rendered my previous theory unlikely – that forking was caused by random damage of the end bud. It happens so much to some tree species that it is a big part of their growth habit. Surely this isn’t accidental damage. Clue number 2 strengthens this argument in that it mostly happens on vigorous branches with healthy buds.

The theory now is this: The side buds are so near the end bud that the auxin hormone has no grasp on them. And with enough power to grow them all, they basically become equal to the end bud. So a couple of side bud could easily take over the end bud, or maybe only nudge the end bud to the side, who knows. Let’s say there’s 2 or 3 new shoots growing out next year. Now these shoots will have equal power and no one of them grows on the side of the others. Without a lead shoot in the middle that pushes the side buds to the sides, the angle is much smaller.

This doesn’t just happen on trees with opposite branching like this maple. European oak trees have the same habit of forming many “side” buds near the end. And they too often form forks with several main branches instead of a single clear main trunk.

