POV-Ray : Newsgroups : povray.binaries.images : Elliptical torus : Re: Elliptical torus Server Time28 Mar 2023 17:46:29 EDT (-0400)
 Re: Elliptical torus
 From: Bald Eagle Date: 2 May 2020 15:45:00 Message:
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William F Pokorny <ano### [at] anonymousorg> wrote:

> It is a cool shape.

Yes, and relatively simple, so I was surprised there wasn't a lot more out there
about Dupin cylcides, Clifford tori, geometric inversion, embedding in 3-space,
Villarceau circles, etc.

> "I couldn't resist trying it..."

lol - well of course not.  :D

> What were you using for settings and seeing for run times?

I have some actual parametric code in the scene that stays commented out, so I
didn't use that.   I use Paul Nylander's method of calculating stepwise points
on a grid of the function and fill in those quadrilaterals with 2 triangles.
This was run in steps of Theta/240 and phi/60

I suppose I ought to calculate some vertex normals and upgrade the code to use
smooth_triangles.   And the face normals seemed to be inverted from what I
expected - so it totally needs work.  But I can mark all the vertices and draw
the grid just by setting the flags to run those code blocks.

And it's - FAST.  :)

Parser Statistics
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Finite Objects:        86557
Infinite Objects:          0
Light Sources:             1
Total:                 86558
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Parser Time
Parse Time:       0 hours  0 minutes  1 seconds (1.639 seconds)
Bounding Time:    0 hours  0 minutes  0 seconds (0.163 seconds)
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Render Options
Quality:  9
Bounding boxes.......On   Bounding threshold: 3
Antialiasing.........On  (Method 1, Threshold 0.300, Depth 3, Jitter 1.00,
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Render Statistics
Image Resolution 640 x 480
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Pixels:           326400   Samples:          128421   Smpls/Pxl: 0.39
Rays:             508059   Saved:              6812   Max Level: 2/5
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Ray->Shape Intersection          Tests       Succeeded  Percentage
----------------------------------------------------------------------------
Cone/Cylinder                     9987            4897     49.03
Torus                            83998           29868     35.56
Torus Bound                      83998           33072     39.37
Triangle                       1160673           84193      7.25
True Type Font                   86841           42100     48.48
Bounding Box                  18792623         5987477     31.86
----------------------------------------------------------------------------
Roots tested:                 33072   eliminated:                13868
Shadow Ray Tests:            118517   Succeeded:                 15672