Set up an environment to attract, deflect or stop new growth. Avoid buildings, simulate a dominant wind direction and grow inside a shape.
The shape of your 3D tree was so far based on genetics. Now it’s time to add a second influence, its environment.
There are several ways in which an environment object can interact with the trees you grow. It can Block growth when a branch approaches too close. It can Deflect growth as if casting shadow. The tree reacts by bending away, toward light. It can also Attract growth, as if it were a light. You can combine these interaction types to get the effect you want to achieve.
This is a good place to clear a common misconception. Plants do not grow toward direct sunlight. If they would, they would all lean south. They would soon lose balance, gravity would not be in their favor. Plants bend only to indirect sunlight, the light bouncing around the sky all around us. It is the blue color that a plant senses and loves.
Type the name of the object to interact with into the Environment text field. A simple mesh object with just several polygons can have a striking effect. Or use the stylized shape of a building to avoid it. Use complex shapes to create a topiary.
With the object selected, its name appears in the lower left of the 3D viewport. If the Grove can’t find an object by that name, you see a warning below the Environment field. The object has to be on a visible layer for interaction to work.
The Attract and Deflect interaction types have a Radius of influence. When a branch grows within this proximity, it gets influenced by the environment. The closer it gets, the more powerful this effect becomes. The Force parameter multiplies this influence.
Environments are not static. Surrounding trees come and go, changing the tree’s exposure to light and wind. Try enabling interaction for just the last years, to simulate a windswept tree.