[QUOTE="Cliff"] It's still Tessellation, John. Once you get there it's hard to get back.[/QUOTE] It is unless the software is designed accordingly. Hardware is so fast today that the mach8ining tesselation is often created on the fly and then discarded unless you specifically elect to save it. [QUOTE] Noise, truncation, approximation, scale, and rounding have all been added but the parent computational geometry may have fled.[/QUOTE] Only the real hacks still do this. They exist but they are very cheap systems. Even RhinoCam at 1K is regenerative. That is the industry buzz word in many places - "Regenerative". Cim Link used to make a big deal about it. They did, IMHO, have a great engine though. [QUOTE] Not to mention the growth in file size & complexity and the needed vastly increased comput power.[/QUOTE] Not much of any issue except to purists like you and I Cliff. Todays kids don't know different and it doesn't matter much. Nobody really cares since there is not competetive dissadvantage in the market place. [QUOTE] Remember: This stuff could all be done in APT in the 1950s ... on machines of that era. 16 KB of memory was HUGE even into the mid 1960s. As for clock speeds ..... anyone remember what they were? One source on the IBM 1620 (1965 ?) says "Clock speed: 0.1MHz (10 µs). Peak FLOPS: 300K"[/QUOTE] Sweet Jesus who in their right mind would want to remember THAT :>)