On 3/8/2016 11:17 AM, Stephen wrote:
>> OK - back to interpolating the control points for my 3x3 bicubic patch
>> model.
>> 16 data points, 128 interpolated control points, 144 control points
>> altogether.
>>   :D
>
> Good luck. :-)
> IIRC Moray had a way of joining bicubic patchs.

I don't know if this will help you. This is a couple of bicubic patches 
that make a cylinder of radius 1. Note that the Y value is 4/3 and in 
Moray, Z is up. (Please don't restart the Maths Vs Engineering, flame 
war. ;-) )



union { // BezPtch001
   object {
     bicubic_patch { type 1 flatness 0.0100 u_steps 3 v_steps 3,
       <-1.000000, 0.000000, 0.000000>, <-1.000000, -1.333333, 
0.000000>, <1.000000, -1.333333, 0.000000>, <1.000000, 0.000000, 0.000000>,
       <-1.000000, 0.000000, 2.000000>, <-1.000000, -1.333333, 
2.000000>, <1.000000, -1.333333, 2.000000>, <1.000000, 0.000000, 2.000000>,
       <-1.000000, 0.000000, 4.000000>, <-1.000000, -1.333333, 
4.000000>, <1.000000, -1.333333, 4.000000>, <1.000000, 0.000000, 4.000000>,
       <-1.000000, 0.000000, 6.000000>, <-1.000000, -1.333333, 
6.000000>, <1.000000, -1.333333, 6.000000>, <1.000000, 0.000000, 6.000000>
     }
   }
   object {
     bicubic_patch { type 1 flatness 0.0100 u_steps 3 v_steps 3,
       <1.000000, 0.000000, 0.000000>, <1.000000, 1.333333, 0.000000>, 
<-1.000000, 1.333330, 0.000000>, <-1.000000, 0.000000, 0.000000>,
       <1.000000, 0.000000, 2.000000>, <1.000000, 1.333333, 2.000000>, 
<-1.000000, 1.333330, 2.000000>, <-1.000000, 0.000000, 2.000000>,
       <1.000000, 0.000000, 4.000000>, <1.000000, 1.333333, 4.000000>, 
<-1.000000, 1.333330, 4.000000>, <-1.000000, 0.000000, 4.000000>,
       <1.000000, 0.000000, 6.000000>, <1.000000, 1.333333, 6.000000>, 
<-1.000000, 1.333330, 6.000000>, <-1.000000, 0.000000, 6.000000>
     }
   }

}


-- 

Regards
     Stephen

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On 8-3-2016 13:12, Stephen wrote:
> I don't know if this will help you. This is a couple of bicubic patches
> that make a cylinder of radius 1. Note that the Y value is 4/3 and in
> Moray, Z is up. (Please don't restart the Maths Vs Engineering, flame
> war. ;-) )

scale <1,1,-1>
rotate 90*x

:-)


-- 
Thomas

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clipka <ano### [at] anonymousorg> wrote:


Parse error.
Expected actual Statement but found misinterpretation instead.
:D  ;)

The auditory sensors were not the location of the malfunction.
Therefore, they need not be coupled to the LCD.
It was a malfunction BETWEEN the auditory sensors.

I'm sure that a fatigued RAID array of optical drives didn't help things.

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The problem I have / had was not joining the patches together - I worked that
out last week with the 4 bicubic patches.

What I'm trying to do now is essentially take the corners of the patches, set
those as the data points, and interpolate the first and last rows to get the 2
intermediate control points of those rows, then run through all of the columns
to set all of the control points in rows 2 and 3.

I got the interpolation all worked out (so I thought), put together 9 patches,
linked all the corners and edges, and coded the whole interpolation of the grid.

Somehow, somewhere, the interpolation doesn't like the data.
I think it's the negative numbers, since my 9 patches are centered on the
origin.
The original javascript outputs, and inputs from SVG - so there aren't any
negative screen coordinates.

Looks like today I might be debugging THAT today to see where it goes
fundamentally wrong.

I can post in scene-files if anyone would like to look and help pick it apart.

or, actually,
Original javascript is embedded in an SVG here:
https://www.particleincell.com/wp-content/uploads/2012/06/circles.svg

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On 3/8/2016 12:18 PM, Thomas de Groot wrote:
> On 8-3-2016 13:12, Stephen wrote:
>> I don't know if this will help you. This is a couple of bicubic patches
>> that make a cylinder of radius 1. Note that the Y value is 4/3 and in
>> Moray, Z is up. (Please don't restart the Maths Vs Engineering, flame
>> war. ;-) )
>
> scale <1,1,-1>
> rotate 90*x
>
> :-)
>
>
You've got a long memory. ;-)

It was strange looking at Pov 3.1 again. It must be 10 years since I 
last used it regularly.

Then I thought about running the benchmark on 3.1
There is none but I came across this:

http://www.verycomputer.com/10_7d4a92f29cb0df5d_1.htm

+A +Ifish13.pov +Ofish.tga +W720 +H486
It took the author 70 hours to run it.
On my i7 machine it took 13 seconds with 3.1g and 3 seconds with 3.7

:-D

-- 

Regards
     Stephen

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OK, upon further investigation, the interpolation is seriously cracked.

Initially I played around with the starting data set in the SVG,
and then when the interpolated patches started wigging out, I went back and
moved the data points around a bit and moved the camera to look at the spline in
z, y, and z.   It _looked_ ok.

The following are interpolated splines for:

#declare DataSet = array [5]{
array[10]{<-40, 0, 0>, <0,0,0>, <0,0,0>, <-30, 0, 0>, <0,0,0>, <0,0,0>, <-20, 0,
0>, <0,0,0>, <0,0,0>, <-10, 0, 0>},
array[10]{<10, 0, 0>, <0,0,0>, <0,0,0>, <20, 0, 0>, <0,0,0>, <0,0,0>, <30, 0,
0>, <0,0,0>, <0,0,0>, <40, 0, 0>},

array[10]{<20, 20, 0>, <0,0,0>, <0,0,0>, <30, 30, 0>, <0,0,0>, <0,0,0>, <40, 20,
0>, <0,0,0>, <0,0,0>, <50, 25, 0>}

array[10]{<-10, 5, 0>, <0,0,0>, <0,0,0>, <-20, 5, 0>, <0,0,0>, <0,0,0>, <-30, 5,
0>, <0,0,0>, <0,0,0>, <-40, 5, 0>},
array[10]{<40, 5, 0>, <0,0,0>, <0,0,0>, <30, 5, 0>, <0,0,0>, <0,0,0>, <20, 5,
0>, <0,0,0>, <0,0,0>, <10, 5, 0>}
};

As you can see, I took the top 2 splines and just reordered the data from
beginning to end (and shifted y by 5).   Not looking good.
Someone please page Jerome.  LeForgeron is needed with his mathematical / c++
cape, to bend this Bezier back in line!  Er, I mean curve!  No, wait - line.
:|

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Attachments:
Download 'retrobeziernegativeproblem.png' (20 KB)

Preview of image 'retrobeziernegativeproblem.png'

On 3/8/2016 1:44 PM, Bald Eagle wrote:
> Someone please page Jerome.  LeForgeron is needed

You are not asking me?
<Rolls on the floor hysterically.>

;-)

-- 

Regards
     Stephen

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Just had a thought. Put aside the original data and use some made up 
data that you know the curve. Then come back to the original data when 
you are happy with your curves.

But before that. Take a raw egg and using a sharp implement pierce both 
ends of the egg. Place the large end in your mouth and inhale. ;-)


-- 

Regards
     Stephen

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Stephen <mca### [at] aolcom> wrote:

> You are not asking me?
> <Rolls on the floor hysterically.>
>
> ;-)

Knowing your love of math, I considered it.
I have a sense of humor like that.
{highfive}

Sometimes I think about what Christoph must wade through when he actually has to
code the engine that has to handle the SDL that I write to do the math and the
CSG and the render....

_"We bow before you, O Mighty Clipka, and beseech you to hear the praises of
your faithful followers, and bestow upon us the Inner Sslt, and the blessings of
your most exalted C++ subroutines.  Hear us, Oh Clipka, and trace us with the
doubly-illuminating rays of your most holy light_source, that we might reflect
upon your SDL and know that it is Good."


{Damn, this is good coffee!}

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On 3/8/2016 2:26 PM, Bald Eagle wrote:
> Knowing your love of math, I considered it.
> I have a sense of humor like that.
> {highfive}
>

High(2.2361)^2

{Fist bump}

> Sometimes I think about what Christoph must wade through when he actually has to
> code the engine that has to handle the SDL that I write to do the math and the
> CSG and the render....
>

That is funny. I never think of it. :-P


> _"We bow before you, O Mighty Clipka, and beseech you to hear the praises of
> your faithful followers, and bestow upon us the Inner Sslt, and the blessings of
> your most exalted C++ subroutines.  Hear us, Oh Clipka, and trace us with the
> doubly-illuminating rays of your most holy light_source, that we might reflect
> upon your SDL and know that it is Good."
>
>

Do you really want a mainland European changing your wetware?
We will end up driving on the wrong side of the road.

> {Damn, this is good coffee!}

Envy! Must use the last of my Blue Mountain.

Ah! Life is good.

-- 

Regards
     Stephen

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