Environment Maps

An environment map is a set of image files that are mapped to the six faces of an imaginary cube surrounding a model (or environment).

In a ray traced image, environment maps are visible only in reflected and transmitted rays.

When an element is reflective but a reflected ray does not “see” any elements, it “sees” the environment map.
The same applies to a transmitted ray that does not “see” any objects in the transmitted (refracted) direction.

A typical usage would be to show reflections of an outdoor scene, using an image of the sky for the top and sides and another image for the ground.

Environment mapping only operates with ray tracing, radiosity and particle tracing.

To assign environment maps to a DGN file

Select the Apply Material tool.

Click the Environment Maps icon.
The Environment Maps dialog box opens.

Click the Browse For File icon.
The Select Environment Map [All] dialog box opens.

Select an image file.

Click the Open button.
The dialog box closes, and the selected file is applied to all faces of the environment cube.

(Optional) To apply a different image or images to some of the other faces of the environment cube, click the Browse For File icon for the required face and select the image file as above.

Click OK.
The Environment Maps dialog box closes and Environment Mapping is enabled in the Ray Tracing dialog box.

To use environment maps in ray traced images

From the Settings menu's Rendering submenu, choose Ray Tracing.
The Ray Tracing dialog box opens.

If necessary, turn on Environment Mapping.
By default, Environment Mapping is enabled when you first Set your environment maps in a design.

If you manually edit a material table file to change or add an environment map, choose Update Environment Maps from the File menu in the Ray Tracing dialog box to read the new assignment.

The imaginary environment cube is constructed slightly beyond the extents of the design file and is not directly visible. It can only be seen in reflections and in transparent objects. The environment cube can be rendered as part of a design if a totally transparent cube is created that surrounds the entire design.

If a model with an environment map(s) is to be animated, it is advisable to create geometry that defines the extents of the portion to animate. This will prevent the environment map(s) from drifting.