Creating with the Add tool

- In this chapter we'll look at the basics of modeling a plant using the graph and parameters. Most tutorials in PlantFactory will start right away with drawing free-form, and that is the default tool, in fact, you'll see that the Pencil icon is highlighted, and I could actually start drawing a plant. However, PlantFactory actually is more of a procedural generation tool and not so much a manual sculpting tool. It can do manual sculpting and we will get to that, but it's a better idea to first get a handle on how PlantFactory actually works in terms of the graph and parameters.

For that reason, I'm going to start by modeling a simple, generic cherry tree or Prunus and that's going to be a good example to illustrate the basic processes of modeling plants in PlantFactory. And that can then be infinitely varied by generating a new seed so for example if we wanted to populate an entire scene with the giant orchard of cherry trees, we could easily do that. If we sculpted the cherry tree completely manually, it wouldn't be as easy to generate a bunch of variations on that.

We'll start by jumping out of the Draw tool, by clicking on the Select tool which is the arrow on the top left. Then we'll create a Trunk segment. We've got a bunch of icons over here on the left to create variations on the segment node, and one of them is the trunk. And these all have dual actions. If you left click you get a different result than if you right click. If we want to just add a Trunk node, then we can just right click on that icon, so I'll do that now, right click, and we now have a trunk added to the graph and also visible in the Preview.

Here it is in the graph, we got that Trunk node. PlantFactory's Add tools are pretty smart, they will add to the end of the current graph. So if I have nothing selected, then when I create branches they'll automatically be connected to the trunk. I'll click to deselect that trunk, and then right mouse drag to slide in the graph. And with nothing selected go back over to the toolbar here, and right click on the Branch node, and automatically the Branch node is created, and a bunch of primitives are placed connected to the trunk.

Each one of these little segments here is a primitive within the single Branch node here. Alright now so over here and slide again so we can see that. If we randomize the seed for this plant, we will get a different variation because some of these parameters have random factors. For example, the width of the trunk is slightly randomized. To get a new plant variation, we can just click on the icon that has a little die and a plant. When you click on that, you get a different variation.

What's happening is within the root node of the graph, there's a parameter called Seed. Let's take a look at that. I'll select that Root node, and in it's General Parameters there's a Seed parameter and that generates the variations throughout the plant. If we give it a different value by entering it in, maybe even type it in, we'll get a different pseudo-random result, or we can just click on the button in order to generate a new variation.

Let's now add another Branch nodes, we'll have two sets of branches. Again deselect, and have nothing selected in the graph, right click on the branch, and what we'll have is a set of secondary branches added. We can see that, now we got one Branch node that has a child of another Branch node. We can navigate in our view here, middle mouse in order to orbit or tumble around. So if nothing is selected and you add a new node to the graph, it'll automatically be added to the end of that graph.

If we intentionally selected something we could cause that new node to be added at that location. I'll select this branch and delete it, just press the Delete key on the keyboard. And then select the Trunk node and issue that command once again, I'll right click on the Branch icon, add another Branch node and now it's coming off of the trunk rather than that first branch. So now we got two sets of branches. And to illustrate that they are in fact different nodes, I can select one of them, go into its parameters and do something like change its length.

You just click and drag here to reduce that length. This is just to illustrate the fact that we can have complex branching structures within the graph, it's not just linear, we can have multiple nodes branching off of the single node. Okay, so that's all I wanted to show you there, we can go ahead and delete that second branch, and then save our scene.