Making Snow in WorldBuilder

Let’s get started.Open Worldbuilder and the default scene. Several necessary elements of our scene are already loaded, including a Landscape mesh object.

In order to view the entire scene, let’s ‘zoom out’ our view. Select Landscape0 in the Scene Tree, and then -in the View Tools- click on Zoom Extents All Selected button.

To create some interesting landscape features, let’s use a Skeleton Line set from our Demo Library. You can open the library two ways:

• click on the Library Window button at the lower left of the WorldBuilder interface; once the window is open, right-click to open DEMO.ODB.
• click and pull down to WorldBuilder Demo Library.

In the Library window, select reef03 from the skeletons group. Drag reef03 into the Scene Tree.

Open a new Camera Viewport by double-clicking on Camera01 in the Scene Tree. Using the Move manipulator, drag the camera in any of the 4 viewports, checking the image composition in the Camera Viewport.

We want to include more of the scene within the camera frame. This is like using a ‘wide angle’ lens with our camera.

In the Property Tree, select Projection and increase the FOV (Field of View) parameter from the default value of 48 to 60.

With the Landscape still selected,
change these Skin values as follows:

Evolution: 50
Roughness: 57

In the Scene Tree select the Landscape.
In the Property Tree select Settings, and change the Mesh Resolution from the default of 64 to 256.
You should be able to see the density of detail increase in the Camera Viewport.

In the Camera Viewport, render the scene in Draft Preview mode. We see the material applied to our Landscape.
Now we’re going to add a texture to simulate snow over the top of our rocky texture. In the Library, select and drag snow02 onto Area 1 (full).

Let’s render the scene again.

Our landscape has turned completely white. This is not quite the effect we’re trying to produce. We want to make it look as though the snow has only been falling for a short time, and hasn’t yet covered the landscape.

With the addition of snow02, a new Placing Conditions modifier appears automatically on the Property Tree. We will use this to make the snow texture selectively ‘stick’ to certain areas on our landscape.In the Placing Conditions panel, first un-check the Ignore All feature.

Next, let’s make our Altitude Range extend from 0 (low) to 140 (high).

Change the Slope Angles Range to 25 (max); leave (min) at 0.

Check the results in the Camera View.

Now that our snowy landscape’s materials are in order, let’s make some adjustments to our skies.Because our scene depicts an overcast lighting scheme, there will be no need for a bright lens-flare effect. Right-click and pull down to ‘Delete’ to remove the SunDiskWithHalo.

Now let’s alter the Sky Gradient property.

We need to change the default color settings in the Ramp Layer. Select Ramp Layer in the Scene Tree and then Color Gradient in the Property Tree. The Sky Gradient Editor will open.

The color on the left hand of the gradient represents the sky at it’s deepest blue directly overhead; the left-hand gradient color represents the sky at or near the horizon, where the color is lighter.

Click on the Key Creator Pencil button.

Now click on the Color button. This opens a standard Windows Color Picker. For the Zenith color, choose a dark purple color and click OK. The selected color is now ready to apply to the Sky Gradient. Click once above the Zenith color key (the small triangular marker on the right). The new color is applied to the gradient.

Repeat this procedure to set the color for the Horizon color key. Use a lighter color.

Now let’s soften the gradient itself. Change Gradient Depth from the default value of 18 to 45.

Here’s how our scene looks with the adjusted Sky Gradient.

Now it’s time to give our scene a little more cloud coverage.
In the Scene Tree expand CompoundSky, then click on AltoStratusClouds.

Select Noise in the Property Tree.

Change the Coverage value from 0.5 to 1.

Check the results by re-rendering in the Camera View.

Notice the rather severe appearance of our clouds.

This is due to the high contrast between the thin and thick areas in the clouds. WorldBuilder’s rendering engine ‘sees’ and draws thick areas as dark (almost black), and thin areas as lighter shades of gray. Also, there is a great deal of sharp detail in the clouds. Because we will soon add falling snow to our scene, we want to de-emphasize the high-contrast cloud detail, in order to make sure the snow is clearly visible against the sky background.
Let’s adjust the Fragmentation value from 3 to 2. This will soften the cloud detail.

Now, increase Brightness from 1 to 4.

Next, set Feathering from 0.2 to 2.

Turning down Shadow Density from 0.85 to 0.45 will also lessen the contrast.

Let’s render again in Production mode to see how these settings affect our scene.

It’s time to add our Snow object. In the Creation toolbar, click once on the Rain/Snow button. The cursor will change to placement mode.

Click once in the Top Viewport to place the Rain/Snow object. Move Rain/Snow above the Landscape.

With the Rain/Snow object highlighted in the Scene Tree, click on Settings in Property Tree. In the panel, Rain will be the default type. Click on Snow.

In the Property Tree, right-click on Material and pull down to Add…

We’ll need to add a base color to the snow, otherwise it will render as black.

In the Select Type(s) of Objects window, choose Constant Color and click OK. Under the Constant Color panel, click on Pick Color, choose white as the new color and click OK.

Our snow particles are now the correct color.

Now let’s simulate ‘atmospheric perspective’ (the phenomenon wherein distant objects appear lighter than closer features).In the Scene Tree, select Scene. In the Property Tree, right-click on Atmosphere and pull down to Add…

In the Select Type(s) of Objects, choose Haze from the Volumetric Shaders group and click OK.

In the Haze filter’s Properties Page, choose a light blue color.

Increase the Half Transparency Distance values by 200% (for all three color channels), and lower Max Distance from the default 10000 to 2500.

Let’s see how our scene looks with the Haze filter applied by re-rendering in the Production mode.

That’s looking better! The Haze filter really gives our scene a sense of scale.

For an added feeling of distance, let’s add another filter. This time we’ll use Fog, using the same method we used to add Haze.

Let’s change the color channel settings from the defaults: decrease the red and green components, and increase the blue component.

Decrease the Max Fog Distance.
This is the distance beyond which the Fog filter will stop affecting the scene. By moving this point closer to the camera, we increase its influence over the distant features in the landscape.

Increase the Transparency Distance.
This is the distance (from the camera) beyond which the Fog effect becomes opaque. By increasing this value, we can keep the foreground features unaffected by the filter.

Let’s render the scene again in Production mode.

The Fog filter really adds a sense of space, and enhances the feeling of cold!

This concludes our introduction to WorldBuilder’s Rain/Snow tools. We hope you found this tutorial fun and informative.

Good luck, and happy WorldBuilding!