Rhinoceros Environment
The Environment tab controls the environment which will be used in the exported MXS, and contains all of the parameters necessary to control each Environment Type. There are four types of environment available; Sky Dome, Physical Sky, Image Based, and None. The environment for a scene is set by using the drop-down list contained in the main Environment group. The Sun may be enabled regardless of which environment type is chosen.
Sky Dome Parameters
When Sky Dome is chosen as the Environment Type, the scene will be lit by a sphere of light, the intensity of which is controlled by the Intensity parameter. The angle specified by the Gradient parameter determines the point at which the Zenith and Horizon colors are evenly mixed.
Physical Sky Parameters
When Physical Sky is chosen as the Environment Type, the scene will be lit by an all-encompassing dome of light generated by Maxwell to simulate the appearance of a natural sky. For information regarding the parameters in this panel, see Physical Sky.
Image Based Parameters
The Image Based Environment Type allows you to light the scene using HDR (High Dynamic Range, i.e. MXI, EXR, HDR) images. There are four Image Based Channels provided: Background, Illumination, Reflection, and Refraction; for more information on how these channels are used, see Image Based Lighting.
Parameters which have no context, given the state of other parameters, are not shown. For example, until a channel’s path has been set to point to a valid file, nothing is shown for that channel except for the path chooser. When a path has been specified, but the channel is not enabled, all of the parameters, except for the path and the ‘Enabled’ checkbox, will not be shown. As a shortcut, holding down CTRL while adjusting parameters in one channel will cause the change to be effected in all four channels.
Besides these per-channel parameters there are also three other main parameters available in the Image Based Environment Type:
Use Interpolation Â
This option turns on render-time pixel-interpolation for environment HDR images.
Use Background for all Channels  Â
Most often, it is not necessary or desired to use four different HDR images in the Image Based environment. When this is the case, enable the ‘Use Background for all Channels’ option to have the plugin write all channels using the values defined in the Background Channel. When this is enabled (this is the default), the user-interface will not be cluttered by the unnecessary channel groups and parameters.
Disabled Channels Use     Â
When there are channels which are disabled, or which have invalid paths set, the ‘Disabled Channels use’ drop-down will be shown, allowing you to choose which environment type to use in those channels.