How to create a simple tree (for GrowFX 1.9.5)

Below you'll find a step-by-step guide how to create a simple tree.




Definitions:

Options and parameters in a red frame need to be modified. Other parameters can remain by default.


Step one is to create a trunk. Add a new path and name it "Trunk".



Click the Distributors button on the command panel to open the distributors window and add a distributor (Distributor), leaving default parameters:



Click Direction Modifiers button to open the direction modifiers window and set these path parameters:

Length path = 300.0cm;
Chaos % = 30.0;
Steps = 6.0cm;



Add one more path and name it "Branches". This will be branches. Set the same parameters as for the Trunk path:

Length path = 300.0cm;
Chaos % = 30.0;
Steps = 6.0cm;

As a distributor, add Path distributor and select Start path to be equal to "Trunk".

Specify parameters as shown in the picture below:


Enable the graph for Density and configure it as shown in the picture:



Return to the Trunk path and add the following direction modifiers: Noise direction and Deviation direction. Set up their parameters as shown in the pictures below:



Define the graph value of Strength for the Noise direction as the following graph:


It'll give a trunk a more straight direction in the beginning and more curvature in the end.

The possible result is shown in the picture below:



Then, for Branches in the distributor, click the button labeled Parameter: Path position. The Affects window opens. Add the influence on their length, i.e. add Branches -> Length. Then enable the graph for the Factor parameter.

Since we'll use multiple levels of branches, enable the Calculate all levels option. This reduces the length of the branches on top levels.



For Branches in the distributor, set Levels to be equal to 7, click the Parameter: Levels button and add the following influence: Branches -> PathDistr_01 -> Start position. Then set the Source parameter range to be equal to [0.0 ... 3.0]. It'll a little increase the number of branches on top levels:



As a result, you'll get a tree model as shown in the picture below:




Then add the same direction modifiers for Branches as you did for Trunk: Noise direction and Deviation direction. Set up their parameters as shown in the pictures below:



That's the final step of creating the basic shape of the tree. The tree will look as in the picture below:



Now you need to assign meshes to a trunk and branches.

Click Mesh Builders button on the command panel to open the meshes window and add Cylinder mesh for Trunk.

Set up the following parameters for the mesh:



Enable the graph for Radius and configure it as shown in the picture:



Its maximum radius will be equal to 8.0cm and go down to 0. Naturally, it won't reach zero thanks to the Min radius parameter which is equal to 0.1cm. Set Face size to be equal to 2.0cm. Configure Radial offset and Scale offset graphically too. It'll give a little curvature to a trunk:



Configure the graph for Scale offset in such a way so that the curvature appears only in the lower part of a trunk:



Then copy Cylinder_mesh_01 and paste it for Branches. Here you can disable graphs for Radial offset and Scale offset. To reduce the radii of the branches on top levels, enable Auto radius and ensure that Radius < Parent radius is enabled. Leave other parameters unchanged.



For branches, we change the graph for Radius as shown below:



Some artifacts may appear:


They are caused by the use of a low value for Tolerance in the Deviation direction parameters when adding extra points. Increase these values for Trunk and Branches and set them to be more that 1/3 of a path step in Steps.


Now let's create leaves. Create a new path and name it LeavesStem. This will be stems for leaves. First, add the Path distributor. In Starting path, add Branches and Trunk paths, then configure it as shown in the picture:


We set the Start position, equal to 60%, to reduce it to 0 on top level branches, add the influence on Start position, depending on the level of a branch. That is for the Branches path in the distributor, open Parameter: Levels, and add LeavesStem -> PathDistr_01 -> Start position. Set Source parameter range = [0.0 ... 4.0], and set the graph for Factor as shown below:


As a result, Start position of stems up to 4th level will be reduced to zero.


Now set path parameters:

Length path = 3.0cm;
Steps = 1.5cm;

Add Vector direction with Strength = -100.0. Stems will slightly bend down.



Add one more distributor Path position distributor. In Starting path, add Branches and Trunk paths:



Now add Cylinder mesh and configure settings as shown in the picture below:



Please note that Mat ID body = 2. This will make leave stems look different from branches and have another material.

You can prepare the material and assign it to a tree. For all GrowFX objects, it's recommended to use Multi/Sub-Object material. Create a double-sided material for leaves.



Now create leaves. Create a path named "Leaves" and set up its parameters in the following way:



The result will look as in the picture below:



Add Leaves mesh and set up the following parameters:



Please note that Mat ID is equal to 3 in order to assign a relevant material to leaves. We increased Face size for better optimization.

To make leaves face upwards, add one more direction modifier for the LeavesStem path. To do so, add Vector orientation direction and set up parameters as shown in the picture below:



That's all. The tree will look like in the picture below:




To download this model, click this link: SimpleTree_02.max