Extensions are applied to geometry to change how it is rendered. In some cases, an extension will modify its geometry, while in others, it will replace it entirely. The extensions currently available in this window are:
To create a new extension, right-click and choose the type of extension you wish to create. To assign an extension, select the desired geometry, and use right-click > Assign to Selected, or use the Extensions list found in the Object Properties panel. To edit the parameters for an extension, double-click it to open it in the Extension Editor (shown here editing a Maxwell Grass extension):
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The Extension Editor works much like the Material Editor: to edit a given extension, select it in the Extensions list. Following is information about the various extensions.
Maxwell Grass
Maxwell Grass is a modifier – it adds grass blades to assigned geometry. There is not a great deal to say about it here, which is not covered in the main Maxwell Grass documentation.
Maxwell Sea
As of plugin version 3.0.3, there are two ways of using the Maxwell Sea Extension: by directly assigning a Maxwell Sea Extension to arbitrary geometry, or by using the Maxwell_CreateMaxwellSea command (also available from the Functions toolbar):
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For information pertaining to the actual Maxwell Sea parameters, please see the main Maxwell Sea documentation.
Animation
Since there is no concept of time in Rhino, it is not possible to automatically make use of the Reference Time parameter in Maxwell Sea; rather it is necessary to animate the scene via script, taking the opportunity at the export of each frame, to set the Maxwell Sea Reference Time value as desired. Here is a macro that will render 100 frames, animating the sea at 25 frames per second:
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If you paste this into Rhino's Macro Editor and run it (or put it in the Command of a toolbar button), it will export a 4-second animation with the sea animated to match the frame rate. As shown in the commented-out (i.e. green) lines, it is also possible to combine this with animations created using Rhino's Animation Tools or Bongo; it is simply necessary in those cases to set the current frame (assuming that enough frames have been defined, using e.g. SetTurnTableAnimation) before exporting each MXS:
Maxwell Volumetric
The Maxwell Volumetric Extension replaces its assigned object with a volume containing a simulation of participating media; it is the host object's axis-aligned bounding box which will define the volume. If an object has both Maxwell Sea and Maxwell Volumetric extensions assigned, it is the Maxwell Sea extension that will be exported. For information on its actual parameters, please see the main Maxwell Volumetric documentation.