McNeel Explains Leopard and 64-bit Rhino for Mac Users

In early November McNeel announced an updated Wanatchee build for Rhino on Mac OS X — currently the popular advanced NURBS modeling application is in a protracted beta state as the developer both advances its core functionality while testing and fixing new code for the native Mac OS X release.

However, of particular note from the latest Wanatchee build was the “requiremen” for Mac OS X Leopard (10.5.5). Architosh was interested to find out why only Leopard was now supported and learned it had something to do with 64-bit support and user interface APIs.

Rhino to be full 64-bit Application

“I would answer the ‘Why Leopard?’ question differently than Bob did,” said Marlin Prowell, a McNeel software developer working on the Mac version. “Rhino is not yet, but will in the near future become a 64-bit application. Both Windows and Mac Rhino users attempt models that do not fit [into] a 32-bit [memory] address space,” explains Prowell.

Rhino, like many other 3D CAD and CAID (computer-aided design) software applications, is being utilized more and more by users who are pushing the envelope with models with huge geometry data sets. Today’s workstations hold vast amounts of storage and have the multi-core processors (often up to 8 cores) to throw at these large models. What users are routinely running into are the memory limits. 32-bit applications (and systems) can only address 4GB of memory. (ed. note: a really good read on this limitation can be found here). 

Leopard’s 64-bit Goodies

“Leopard is the first OS X version that supports a 64-bit GUI application,” continues Marlin Prowell, “So, to ship a 64-bit version of Rhino, we must require Leopard at a minimum.” 

“Although the current version of Mac Rhino is not [yet] 64-bit, I have been adding some of the user-interface [goodies] that take advantage of Leopard’s capabilities,” says Prowell. Such Leopard UI-goodness in the very lastest Wanatchee build for Mac include the Leopard HUD panels (the transparent black head’s-up dialogs) that many Mac Leopard users are familiar with in tools like Apple’s free iPhoto and tools like Aperture. 

Yet while McNeel has begun in earnest to finally start work on a native Mac OS X interface for Rhino Mac beta, it was working on the foundation of the program for all users (Windows users included) that was the real requirement driving Leopard exclusivity.

As Marlin Prowell notes, “The real motivation was laying the groundwork for 64-bit Rhino.”