WorldBuilder Tutorials

Snow Tutorial

Snow Scene tutorial

There is no button "put snow into the scene" that WorldBuilder allows, but you can easily build a landscape covered with snow, a forest with snow on branches and set up the lights to simulate winter. Here are some hints about doing all this things.

We will start with the lighting. Typically, shadows in winter are of a distinct blue tint. Make the ambient light a little bit bluish, but close to mid-intensity gray. Place a parallel light source slightly above the horizon in the scene since, since the sun in winter is close to the horizon. The color of the parallel light can be a little bit yellowish. Do not make blue and yellow tints too string, because it will make the fine tuning object's photometry more difficult.

Snow on the terrain. The simplest way is to use material with consistent color. Select the off white color, slightly blue. Photometry: set diffuse and specular high so, that the lighted areas will be almost white. Bumping adds a natural look to the snow. Use some noisy texture for bumping, like "bump.bmp", available in the standard Maps directory. Set its tiling to high values and set some super-sampling to smooth the noise in a distance.

If you want to stress the contrast between snow and bare land or rock, add some soil or rock material to the same area. Use placing conditions to distribute rock on steep slopes and in a specific range of altitude. It will produce some patches of bare terrain.

Grass adds more realism and also helps to hide bump tiling. Again, use white and blue-almost-white colors for it and set the photometry as was done in the snow material. Extra grass with different but close color can add more life to the scene.

Trees. Only trees with airbrush style foliage can be easily converted into snow-covered trees. Again the same trick works - set some snow material to the foliage. Hint: it would be good to place the same basic snow material into your custom library and add it to different objects, like trees, and vary it slightly. Trunks should be textured with some dark-gray texture. In WB 2.1 there is a Procedural Textures plug-in that allows one to make composite material. You can combine bark and snow material in one and use the placing conditions to place snow on parts facing up. This trick gives the impression of a thin layer of snow and can be used for trees in large areas.

For single trees you can create a copy of a tree, shift it slightly up, and assign to it the same snow material. It will give the impression of a thick layer of snow on the tree. I would suggest using this for trees on close view only, since making copies can be memory-expensive.

You can leave the scene without fog, to make a sunny clear day. For the same reason you can remove clouds and make the sky deep blue (the default sky is OK). Shadows from trees also help to add to the winter sunny day impression. Do not forget to switch on shadows in the light source and shadows for the trees in the area whenever you need them!

Fog and more clouds turn everything into different weather, and of course, you will need to adjust the lighting too.

Igor Borovikov. E-mail: igor@animatekusa.com