POV-Ray : Newsgroups : povray.object-collection : SphereSweep 2.0 and PointArrays : SphereSweep 2.0 and PointArrays Server Time: 25 Oct 2020 02:03:42 GMT
  SphereSweep 2.0 and PointArrays  
From: Cousin Ricky
Date: 10 Sep 2020 01:34:31
Android's new logo is just a disembodied head, and it turns out that 
extrapolating the head to reporportion the rest of the robot takes a bit 
of math.  Well, arithmetic mostly, but you need math to figure out how 
to apply the arithmetic.  So, even though I wrote in the last thread 
that AndroidRobot has priority, SphereSweep 2.0, though unfinished, was 
at a stopping point, and all I had to do was excise the unfinished code, 
update the user manual, and do final tests.

It turned out that, thanks to the _correct_ way to downgrade a cubic 
Bézier to a quadratic, the Bézier bug in SphereSweep 1.2 wasn't as 
consequential as it initially appeared to be, reducing the urgency of 
this upgrade.  But if I hadn't decided to post the upgrade, with the 
final scrutiny I give my modules before uploading them, I wouldn't have 
discovered my error on how to downgrade the cubic.  The apparent urgency 
of the upgrade is what revealed that it wasn't urgent!  But the module 
is done, so here it is.

The main new feature of SphereSweep 2.0 is conversion macros between 
SphereSweep and another Object Collection module, PointArrays.  As I was 
finishing up SphereSweep 1.2, I discovered there was quite a bit of 
overlap between SphereSweep and PointArrays, and I figured maybe some 
POVers might want to take advantage of features of both modules. 
However, their data structures are incompatible, so I wrote the 
conversion macros.  I hope you find them useful.

Since downgrading a cubic Bézier isn't as simple as I thought, there 
will definitely be a quadratic Bézier spline in a future version of 


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