The Grove / Learn / Grow

Grow

Let nature take its course and watch trees develop into beautiful shapes. Mimic any tree’s character with intuitive parameters taken straight from the woods.

Grow feature illustration

Terminology

To learn how to grow your own 3D tree, first quickly get up to speed with terminology in the arboreal world. A branch consists of nodes connected by internodes. Each node represents the place along the branch where a leaf grows. Between the leaf and the branch grows a bud, the embryonic beginning of yet a new branch.

The number of nodes a branch grows depends on its health, its species, the age of the tree and growth hormones. Willows are well known for their long twigs with lots of nodes.

Which brings us to twigs. Twigs are fresh branches grown this year. They are very different to the rest of the tree, and can best be described as one year plants. Twigs are the branches to carry leaves, flowers and fruit. Most twigs don’t survive winter, but the ones that do turn into woody branches. Moving on, the branch that started the whole tree is the trunk.

Interface and Presets

The interface guides the artist by following the same order as the simulation it steers. At the top you can Reset (chop down) your current tree and pick a Quick Start preset species. Then continue down, change the parameters and grow your tree.

There are thousands of tree species and cross species. A small number of those species are well known to everybody, like oak, willow and linden. Those are going to be the trees you need to create most, as they are most common. Their growth parameters are a good starting point for any cross species. Studying these will soon teach you each parameter’s impact on a tree’s shape.

If, after editing parameters, you are happy with the look of your tree, you can save it as a preset by clicking the plus-sign button to the right of the Quick Start menu. Enter a name, then either Overwrite or Add the preset.

Presets are saved as plain text files describing all relevant parameters. If you want to manage, delete or manually edit presets, you can with any text editor.
On Windows, presets are saved to: Users/{Username}/AppData/Roaming/Blender Foundation/Blender/{Version}/scripts/addons/TheGrove{Version}/Seeds/
On OSX, this is: ~/Library/Application Support/Blender/{Version}/scripts/addons/TheGrove{Version}/Seeds/

Buds and Branching

A bud contains the potential for growing a new branch next year. Come spring, not all buds open to grow a new twig. Some get damaged by frost or insects, others remain dormant. The parameter Branch Chance controls the chance a bud has to open and grow a new branch. Bud Life sets the number of years after which a dormant bud still has a chance of opening.

After that, there is still a chance for a node to grow a new bud, known as a spontaneous bud. Some species grow lots of spontaneous buds, especially willows after rigorous pruning. Trees damaged by storm or insects will also fight to grow extra buds. The Watershoots parameter controls the chance of forming these buds. Consider using spontaneous buds late in development to simulate a hard time.

When a bud does grow a new twig, it’s at an angle to its parent branch, the Branch Angle.

One last parameter controls branching and has a big impact on the look of your tree, the Branching Type. Most trees grow a single bud at each node, each successive bud alternating sides on the branch. This is what botanists call Alternate branching. A small number of trees grow two buds at each node – one at each side – called Opposite branching. Trees like Maple, Horse Chestnut and Ash show opposite branching.

Growing a new twig

After the fate of a bud turns out favorable, it pops open to grow a new twig. This twig will grow a length of New Nodes times Internode Length. It will grow at an angle to the parent branch, the Branch Angle.

Nature exposes trees to forces like wind, cold and even insects. A branch experiencing these forces rarely grows in a smooth line. So add some realism by randomizing each new node’s direction with the Random Heading and Random Pitch parameters. Heading is the horizontal direction, pitch is the inclination toward vertical.

Now what makes a tree grow up and its roots grow down? Trees regulate growth with hormone molecules, communicating what to do to different organs. The distribution of hormones determines which parts grow and which way it grows. Some hormones are free to move by gravity, concentrating at the bottom of branches. By growing more cells on the bottom of a twig, it bends up to the sky.

Botanists call this effect gravitropism. Tropism is a fancy word for bending or turning, Gravi is short for gravity. I just call it Turn To Gravity. Most trees show a negative gravitropism, with twigs turning up to the sky instead. The effect of gravitropism is partly countered by bending under weight.

Grow groups of trees

The shape a tree evolves to depends a lot on its surroundings. A tree growing in open field has no competition for light and can grow a wide crown shape. In a grove of trees, the inner trees tend to grow higher and much more slender while competing for light and space.

True to its name, the Grove grows groups of trees just as well as a single tree. Watch trees compete for light and form a unified, well balanced crown shape. Grouped trees are often much more appealing and add natural realism.

Need to create a hero tree with total control? Sculpt your own trunk and main branches. Then distribute empties where you want to finish off the tree with grown branches.

Nature or nurture

The Grove has a strong eye on realism. Let nature take its course and watch trees develop without labor intensive user input.

No painting of new branches, no precise control over numbers of sub branches. Although these features give an artist control, they make creating a balanced tree a hard job. Following the rules of nature makes for a predictable and surprisingly easy experience. Despite the complex algorithms under the hood, the Grove is a joy to work with.

With the Grove, like in nature, you can shape a tree with an environment object. Learn more about environments in Interact.

Know your tree

A recent study by Yale University estimates there are a total of 3 trillion trees – 420 trees to every person – on earth. They surround us everywhere. We think we know our trees, yet the mental image we have of them is often quite different from reality. If you want to recreate a tree species, observe it with care. Find pictures of the tree at different ages. Winter time is when a tree’s branching structure is best visible. Try to get your hands on a twig and model it to scale.

Get to know the ins and outs of tree growth with the Grove 3D tree growing software. Read the blog post on How Trees Grow to get into the terminology.

Next up, learn more about: Bend.