Creating a cloudy sky background environment

First, you will create a sky texture with clouds for the background of the scene.

1. Open the Multi-lister window, and display only the shaders (Render > Multi-lister > Shaders).
2. Double-click the Environment shader to open the Environment control window.

   

   The environment shader allows you to determine the type of image that is produced in the background of your scene. The environment can be either a 2D image or a series of images that produces a 3D environment.

   

3. In the Background section, click the Map button next to the Color field to open the Texture Procedures window.

   

   There are three types of textures: Surface, Environments, and Solid.

4. Click the three texture tabs to open them.

   

   The Surface section contains 2D textures.

   

   The Environments section contains procedural environments that give the appearance of real objects in the scene without adding additional geometry.

   

   The Solid section contains textures that appear to be created from a block of solid material, like wood or marble.

   

5. Click the Sky button in the Environments section.

   

   This opens a parameter window called SkyTexture. The sky texture is a very “procedural texture” that simulates a sky. “Procedural” means that the program executes a series of commands to create the texture, instead of using a 2D image of the sky. The sky texture can simulate a sunrise or sunset, or you can create a sunset as it might appear on some faraway planet.

   

   For this example, you will not be creating an animated sky, but you will create a static sky.

6. In the SkyTexture Control Window, click the Cloud Parameters tab.

   

   This section contains variables that control the clouds in the sky. Currently, there are no clouds in the sky texture, as you can see in the Multi-lister swatch. One way to create clouds is to map a two-dimensional texture to the Cloud texture variable.

7. Click the Map button next to the Cloud texture variable.

   

   The Texture Procedures window appears.

   

8. Click the Fractal button in the Surface section. This is a two-dimensional texture that works well to simulate clouds and other textures like fog or smoke.

   

   A new control window appears called Fractal. You do not need to edit the default variables for the fractal texture, because they are sufficient for producing a good cloud image.

   

   NoteThe Multi-lister now contains a Fractal swatch. The Fractal texture is used to simulate clouds. These clouds are visible in the SkyTexture swatch.

   

9. Click the left arrow at the top of the Fractal control window.

   

   This brings you back to the SkyTexture control window.

10. Click the Floor Parameters tab to open this section.

    

11. Click the OFF option next to the variable Has_Floor. This turns off the default floor in the Sky texture. We do not need the floor, because the table top obscures the ground.

    

    The floor disappears from the SkyTexture swatch in the Multi-lister.

    

12. In the Sun_Parameters section, drag the slider in the Elevation field down towards zero. Notice that the sky texture in the Multi-lister becomes orange, as it does in real life at sunset, and finally black.

    

    Now, drag the slider back to its maximum value. Notice how the sky texture changes from black to orange and finally to a very bright washed out color.

    Set the Elevation value to 40, to mimic the sun at noon. Change the size of the sun variable from a value of 0.531 to 2.0 and change the azimuth value from 145.0 to 0.0.

    

    The SkyTexture swatch updates.

    

13. Close the SkyTexture Control Window and the Multi-lister.

Rendering the scene

Now, you will render the scene to see the sky texture.

1. Select the Render command (Render > Render).

   The File Browser opens to the pix directory of the Lessons project.

2. Type render4 in the Object name field (Windows) or Save As field (Mac), then click the Save button.

   The File Browser closes and the render begins.

3. Click the Show button on the Render Monitor to view the rendered image.

   

   NoteThe sky texture is in the background of the image. Because the sky texture surrounds the scene, if you moved the camera angle and re-rendered the scene, you would see the sky from another position.
4. Click the close box in the Render Monitor window and the rendered image window to close them.

Save your work

1. Save your work in the wire file of the Lessons directory.
2. Name your file myadv_rend2.wire.