Apply 3D environments

If you are raytracing your scene, any reflective surfaces will accurately reflect the environment.

To use image-based lighting

Open the Environment shader.

Instead of mapping an environment texture to the Background color choose a high dynamic range image reflection map to use in the Image-Based Lighting section. Browse to the HDR image, and choose it.

To evaluate the mapping, ensure that Use Environment (this option used to be called Refl. Background) is turned ON in each shader that you want to use an image-based lighting environment.

Turn on Use Environment in WindowDisplay > Hardware Shade

As you can see from the following image, all of the shading parameters of each shader affect the appearance of the image-based lighting.

Note that there are two Image-Based Lighting (IBL) environments provided in the shader library, and that most of the shaders in the library have been adjusted to work well with IBL.

After you have loaded the HDR image, you will probably need to adjust the tone of it; since HDR images cover a wide range of lighting conditions, the default selection may not be the look you want. Open the next section of the Environment shader, the Tone Mapping section.

Adjust the Exposure, Saturation, and Gamma sliders to adjust the color, brightness, and tonal range of the HDR image.

Image-based lighting can be used with both Hardware Shade and software Render modes.

Create a 3D environment

Double-click the environment swatch in the Multi-lister to open the Control Window.

See Control Window in Render > Multi-lister

In the Control Window, click the Map button (to the right of the Color parameter) to open the Texture Procedures window.

See Open a texture procedures window

In the Texture Procedures window, click Environments to open the environment texture section.

See Environment parameters in Render > Multi-lister

Click the button of the environment texture you want to use.

An environment texture swatch appears in the Multi-lister, the environment texture is displayed on the environment swatch, and the Control Window updates to display the environment texture parameters.

Customize the environment texture by editing the parameters in the Control Window.

Create a Ball environment

To create an image of a chrome ball, first place a highly reflective chrome ball (sphere) in the environment (real world or computer generated) that you want to re-create. Place the ball at the exact location (in the original environment) where you want your model to appear (in the re-created environment), and take note of the ball's distance from any floor/walls/ceiling or large objects.

Photograph (or render) the ball using a telephoto lens, and take note of the camera's elevation (the angle between the camera's view and the environment's ground plane), and the camera's inclination (the angle between the camera's view and the environment's YZ plane).

The photo essentially contains a compressed sample of the entire environment, except for the area directly behind the ball. The highest resolution is in the direction of the camera, so the image provides the best data compression for that point of view.

A Ball texture that uses a single photograph of a ball has two limitations: the missing area directly behind the ball, and the decreasing resolution toward the edges of the ball. You can overcome these limitations by taking a series of photographs of the ball (up to a maximum of 32). The photographs must be taken on the horizontal plane of the ball (that is, not above or below the ball), at a constant distance from the ball, and at equal intervals around the ball. The Ball texture will automatically select the best image for any particular view (that is, no missing area and maximum resolution). Name the image files <filename>.1 through <filename>.n, where the files represent a sequence going clockwise around the ball when viewed from above.

Remove the ball from the environment, and photograph (or render) the environment again using the same camera position, elevation, and inclination, but a wider angle lens (for example, 24mm to 50mm).

The Ball texture can best re-create environments that have no objects in their center (that is, near the chrome ball). For example, rooms and interiors should not contain furniture, and outdoor scenes should not have trees or cars near the chrome ball. (In general, outdoor scenes can contain buildings).

If you are using a single image of a chrome ball, map a File texture to the Ball texture's Image parameter, and then map the image file of the ball in the environment to the File texture's Image parameter.

If you are using a series of images of a chrome ball, map a Volume texture to the Ball texture's Image parameter, and then map one of the image files to the Volume texture's Pix Sequence parameter. Set the Volume texture's From and To parameters to the extensions of the first and last image files in the sequence (1 and n).

Map the image of the environment without the chrome ball to the environment's Backdrop parameter.

Set the Ball texture's Inclination and Elevation parameters to the inclination and elevation of the camera used to photograph the ball.

For accurate reflections of the re-created environment on your model, set the Ball texture's Projection Geometry parameters to values corresponding to the distance between any floor, walls, ceiling, or large objects and the chrome sphere when it was photographed.

To simplify the positioning of the environment's Backdrop image, set the Ball texture's Eyespace toggle ON. To model background geometry (for example, so you can add shadows, lighting effects, or fog to your scene), set the Ball texture's Reflect toggle OFF.

Create a Cube environment

To use a cube texture to simulate reflections from a real-world or CG environment, from the center of the environment in all six directions either take photographs of (real-world) or render (CG) the environment. Then map a cube texture to a shader's Reflection parameter, and assign the six images to the cube texture. Scale and position the texture placement object so that it corresponds to the dimensions of the original environment. Assign the shader to an object in your scene and render (raycast). The object will appear to accurately reflect the original environment.

One of the advantages of the cube environment texture is that you can blur it without increasing rendering time.

Use Bluroffset to unfocus reflections when using the cube environment texture as a reflection map to simulate unpolished surfaces.

The advantage to Cube environment maps is that they can be blurred as much as you want without any additional computing cost. When you generate a background from an environment map, the amount of blurring required to prevent aliasing increases with the field of view. In practice, very little blurring results when you use images with a 5122 texture and a field of view less than 90×.

For reflection mapped surfaces however, the amount of blurring depends on the surface curvature and the distance from the eye point. This cannot be computed automatically. Using the Blur_offset slider in the Blur window lets you unfocus the reflections by a desired amount (see Common Surface Texture Parameters for more information). In fact, soft-focus reflections can be used to simulate less than perfectly polished surfaces.

In order to use a cube texture to map six image files onto the inner surface of an infinite cube, you must set the ALIAS_INFINITE_CUBE environment variable. See the Environment variables online documentation.

The reflections on a surface mapped with an infinite cube texture do not change when you scale or move the surface or the texture placement object. The reflections on a surface mapped with a finite cube do change when you scale or move the surface or the texture placement object.