WorldBuilder 4 Basics – Part 2
Introduction
In Part 1 we built a very simple scene. The goal of the second tutorial is to show how to scatter vegetation in areas and how to edit the shape of areas. As in the first tutorial, we will make extensive use of the Incremental Design feature.
NOTE: The tutorial is designed to be used with the downloadable demo version of WorldBuilder 4. Some features such as scene and rendered image saving are disabled in this version. In order to follow along with the tutorial example scene files, each of the tutorial’s four parts are available for download.
Open the example scene file ‘part2_start.awb’.
Open a camera Viewport by double-clicking on Camera01 (in the Scene Tree).
Render the Viewport using the Production mode.
Click on the Incremental Design Step Forward button.
Refresher: Incremental Design freezes the image with the depth channel and hides objects that were previously rendered. Those objects will not be rendered next time. Only the newly created objects will be rendered and composed with the static background.
Click and drag the mouse to draw a new area. We want to build an area for a forest.
Refresher: Making an Area: Select the Landscape object to access its tools. Right-clicking closes and finishes the area.
We can see our new area in the camera Viewport.
Scattered Vegetation
We need to get some trees to “plant” in the new area.
Let’s return to the Library. Select Aspen 1 and drag it onto the new Area. A new dialog will appear. Here you can select what kind of scattering you want to use. We will select Scattered Vegetation. This will place trees uniformly at random locations within the area.
Now we have to go through the parameters of the scattered trees and modify them.
Select the Size & Density property. Height Range is the first one and it is probably the most important. In many cases it is enough to adjust just this one attribute. First, we need to make an approximation of the height range. Use the examples provided for an idea of how big to make the trees.
We’ll also make the trees render faster by redefining them as Flipboards. Flipboards are single-polygon objects that contain both color and alpha images to simulate more complex shapes. In the Objects List property, enable “Draw as flipboards”. Because this group of trees will be more distant, it will be okay to render them this way. This conversion happens on the fly each time you render the scene.
OK, the trees look consistent within the selected height range. Since the front pine tree is casting a shadow, it is obvious that the rest of the forest does not cast shadow. Let’s fix this.
Find the Shadow & Reflections Property for the scattered trees. By default, scattered vegetation does not cast any shadows. You will have to enable this option. To speed up rendering of the shadow you can render the trees in the shadow map just like billboards. It makes sense especially since the trees themselves are rendered as billboards.
We need another shadow map because the existing one is already being used for the tree in the foreground.
Select Parallel_Light_0. Find the Shadow Options property and right-click on it to access the pop-up menu. Pull down to Add a new Shadow Map. The new shadow is disabled by default. Right-click on it to get to the pop-up menu for the shadow and enable the shadow.
In the Shadow 2 Properties Page, click on the Shadow View in Current Viewport button; the active Viewport will be named Parallel_Light_0 Shadow 2. Zoom into the scene.
Continue until the forest is as large as possible in the Viewport.
As before, when we created the previous shadow map, we don’t want a shadow from the clouds. Ctrl+click toggles the selection in the list of the excluded objects. Notice that both shadows have independent controls, although they are associated with the same light source. This gives one a lot of flexibility and control over shadow appearance.
Since we expect to see a new shadow, we have to clear the Z-buffer and unhide all of the objects.
Note: Before re-rendering, make sure to enable (in the new shadow’s Properties Page) First Frame under the Generate Map parameter.
Re-render the scene in the Production mode.
Now our forest is casting its own shadow onto the landscape.
Before continuing, click on Incremental Design Step Forward to store our recent additions to the scene.
Next we are going to “plant” flowers on our landscape.
Draw another area.
- Select the landscape
- Click on the Create Area icon
- Draw a new area in the Top Viewport
The idea is to draw a small area close to the camera so that we will see noticeable results quickly.
Click-hold-drag to draw. Right-click to finish.
Now we need to pick up a flower from the library. Under flowers, choose AsterFlower 2 and drag it into Area 4.
This time, when we drop the flowers into the area, we will choose Clusters of Vegetation. It will distribute the flowers in clumps.
Select AsterFlower 2’s Size & Density property.
Since we already know the relative scale for the objects, we can guess an approximate height for flowers. Also, we will plant them a little bit closer so we need to reduce the Average Distance to 30.
Select AsterFlower 2’s Clusters property.
This parameter defines the distance in between clusters, not individual plants. This dialog is specific for this type of distribution. It controls clumps (clusters). Knowing the relative scales helps us to set the initial parameters here too.
We can play with the parameters of the flowers in the Area and preview the results by rendering it with Incremental Design, for faster feedback.
In Part 2 of our WorldBuilder Basics tutorial, we:
- used the Scattered Vegetation feature to control the placement of tree (and flower) groups
- optimized render times by converting our tree groups to Flipboards
- added a new shadow map for our tree group
Note: If you are using WorldBuilder Demo, then you will not be able to Save your work up to this point, because that feature is disabled in this version of the software.
You can, however, refer to the downloadable example scene files for this part of the tutorial; all of the objects and property settings featured in this tutorial are present in the files.
Please proceed to Part 3 of the WorldBuilder Basics tutorial.