POV-Ray : Newsgroups : povray.newusers : Sphere sweep appears to be thicker at the base and thinner at the tip Server Time
26 Nov 2022 04:45:23 EST (-0500)
  Sphere sweep appears to be thicker at the base and thinner at the tip (Message 1 to 3 of 3)  
From: Aj
Subject: Sphere sweep appears to be thicker at the base and thinner at the tip
Date: 23 Sep 2022 13:50:00
Message: <web.632df098867c4345220064e63d902b29@news.povray.org>
Hello everyone,

I am trying to fix this problem with my sphere sweep object as mentioned in the
subject. I am not sure if it has to do with the camera positioning or some other
setting.

I have attached the code and corresponding rendered image.

If you look at the base of the object and compare it with the tip, you will
notice that the tip appears to be thinner than the base, any suggestion on how
to fix this problem would be very helpful.

Thank you.

#include "colors.inc"

camera {

        location <5,30,-50>
        look_at <10,10,10>
        angle 80
        }

light_source {
                <1,10,-10>
                color White
             }




background {color rgb<1,1,1> }


#declare Scale = 20*<40,10,1.5>;
#declare Radius = 1;
#declare P1  = Scale*<0,0,0>;
#declare P2  = Scale*<0.00011003,-9.7009e-05,0.010001>;
#declare P3  = Scale*<0.00021841,-0.00019256,0.020002>;
#declare P4  = Scale*<0.00032347,-0.00028519,0.030003>;
#declare P5  = Scale*<0.00042358,-0.00037345,0.040004>;
#declare P6  = Scale*<0.00051706,-0.00045587,0.050005>;
#declare P7  = Scale*<0.00060227,-0.000531,0.060006>;
#declare P8  = Scale*<0.00067755,-0.00059737,0.070007>;
#declare P9  = Scale*<0.00074126,-0.00065353,0.080007>;
#declare P10  = Scale*<0.00079172,-0.00069803,0.090008>;
#declare P11  = Scale*<0.0008273,-0.00072939,0.10001>;
#declare P12  = Scale*<0.00084632,-0.00074617,0.11001>;
#declare P13  = Scale*<0.00084715,-0.0007469,0.12001>;
#declare P14  = Scale*<0.00082812,-0.00073012,0.13001>;
#declare P15  = Scale*<0.00078759,-0.00069438,0.14001>;
#declare P16  = Scale*<0.00072388,-0.00063822,0.15001>;
#declare P17  = Scale*<0.00063536,-0.00056017,0.16001>;
#declare P18  = Scale*<0.00052037,-0.00045879,0.17001>;
#declare P19  = Scale*<0.00037725,-0.0003326,0.18>;
#declare P20  = Scale*<0.00020434,-0.00018016,0.19>;
#declare P21  = Scale*<-1.5898e-10,2.9055e-10,0.2>;
#declare P22  = Scale*<-1.688e-10,2.9921e-10,0.2>;
#declare P23  = Scale*<-1.688e-10,2.9921e-10,0.2>;
#declare P24  = Scale*<-0.00023666,0.0002093,0.21>;
#declare P25  = Scale*<-0.00050341,0.00044902,0.21999>;
#declare P26  = Scale*<-0.00079727,0.00072041,0.22999>;
#declare P27  = Scale*<-0.0011152,0.0010247,0.23999>;
#declare P28  = Scale*<-0.0014543,0.0013632,0.24998>;
#declare P29  = Scale*<-0.0018115,0.0017371,0.25997>;
#declare P30  = Scale*<-0.0021837,0.0021476,0.26996>;
#declare P31  = Scale*<-0.0025682,0.002596,0.27995>;
#declare P32  = Scale*<-0.0029617,0.0030836,0.28994>;
#declare P33  = Scale*<-0.0033613,0.0036116,0.29992>;
#declare P34  = Scale*<-0.0037641,0.0041812,0.3099>;
#declare P35  = Scale*<-0.004167,0.0047937,0.31988>;
#declare P36  = Scale*<-0.0045671,0.0054504,0.32985>;
#declare P37  = Scale*<-0.0049613,0.0061524,0.33982>;
#declare P38  = Scale*<-0.0053466,0.0069011,0.34979>;
#declare P39  = Scale*<-0.0057201,0.0076976,0.35975>;
#declare P40  = Scale*<-0.0060788,0.0085433,0.36971>;
#declare P41  = Scale*<-0.0064195,0.0094393,0.37966>;
#declare P42  = Scale*<-0.0067395,0.010387,0.38961>;
#declare P43  = Scale*<-0.0070356,0.011387,0.39955>;
#declare P44  = Scale*<-0.0070356,0.011387,0.39955>;
#declare P45  = Scale*<-0.0070356,0.011387,0.39955>;
#declare P46  = Scale*<-0.0073058,0.012441,0.40949>;
#declare P47  = Scale*<-0.0075512,0.013546,0.41942>;
#declare P48  = Scale*<-0.0077741,0.014699,0.42935>;
#declare P49  = Scale*<-0.0079765,0.015897,0.43927>;
#declare P50  = Scale*<-0.0081606,0.017136,0.44919>;
#declare P51  = Scale*<-0.0083285,0.018414,0.45911>;
#declare P52  = Scale*<-0.0084824,0.019727,0.46902>;
#declare P53  = Scale*<-0.0086244,0.021073,0.47893>;
#declare P54  = Scale*<-0.0087566,0.022449,0.48883>;
#declare P55  = Scale*<-0.0088811,0.02385,0.49873>;
#declare P56  = Scale*<-0.0090002,0.025275,0.50863>;
#declare P57  = Scale*<-0.0091158,0.026719,0.51853>;
#declare P58  = Scale*<-0.0092301,0.028181,0.52843>;
#declare P59  = Scale*<-0.0093454,0.029656,0.53832>;
#declare P60  = Scale*<-0.0094636,0.031143,0.54821>;
#declare P61  = Scale*<-0.009587,0.032636,0.5581>;
#declare P62  = Scale*<-0.0097176,0.034135,0.56799>;
#declare P63  = Scale*<-0.0098576,0.035634,0.57788>;
#declare P64  = Scale*<-0.010009,0.037133,0.58777>;
#declare P65  = Scale*<-0.010174,0.038626,0.59766>;
#declare P66  = Scale*<-0.010174,0.038626,0.59766>;
#declare P67  = Scale*<-0.010174,0.038626,0.59766>;
#declare P68  = Scale*<-0.010355,0.040112,0.60755>;
#declare P69  = Scale*<-0.01055,0.041591,0.61744>;
#declare P70  = Scale*<-0.010759,0.043063,0.62733>;
#declare P71  = Scale*<-0.010981,0.044529,0.63722>;
#declare P72  = Scale*<-0.011215,0.045988,0.64712>;
#declare P73  = Scale*<-0.011459,0.047443,0.65701>;
#declare P74  = Scale*<-0.011714,0.048892,0.6669>;
#declare P75  = Scale*<-0.011977,0.050337,0.67679>;
#declare P76  = Scale*<-0.012248,0.051778,0.68668>;
#declare P77  = Scale*<-0.012527,0.053216,0.69657>;
#declare P78  = Scale*<-0.012811,0.05465,0.70647>;
#declare P79  = Scale*<-0.0131,0.056083,0.71636>;
#declare P80  = Scale*<-0.013393,0.057513,0.72625>;
#declare P81  = Scale*<-0.013688,0.058942,0.73614>;
#declare P82  = Scale*<-0.013986,0.06037,0.74603>;
#declare P83  = Scale*<-0.014285,0.061797,0.75593>;
#declare P84  = Scale*<-0.014584,0.063224,0.76582>;
#declare P85  = Scale*<-0.014882,0.064652,0.77571>;
#declare P86  = Scale*<-0.015178,0.066081,0.7856>;
#declare P87  = Scale*<-0.015471,0.067511,0.7955>;
#declare P88  = Scale*<-0.015471,0.067511,0.7955>;
#declare P89  = Scale*<-0.015471,0.067511,0.7955>;
#declare P90  = Scale*<-0.01576,0.068943,0.80539>;
#declare P91  = Scale*<-0.016045,0.070377,0.81528>;
#declare P92  = Scale*<-0.016327,0.071813,0.82517>;
#declare P93  = Scale*<-0.016606,0.07325,0.83506>;
#declare P94  = Scale*<-0.016881,0.074689,0.84496>;
#declare P95  = Scale*<-0.017154,0.07613,0.85485>;
#declare P96  = Scale*<-0.017423,0.077572,0.86474>;
#declare P97  = Scale*<-0.01769,0.079015,0.87463>;
#declare P98  = Scale*<-0.017955,0.080459,0.88452>;
#declare P99  = Scale*<-0.018218,0.081905,0.89441>;
#declare P100  = Scale*<-0.018478,0.083351,0.90431>;
#declare P101  = Scale*<-0.018737,0.084798,0.9142>;
#declare P102  = Scale*<-0.018994,0.086246,0.92409>;
#declare P103  = Scale*<-0.01925,0.087695,0.93398>;
#declare P104  = Scale*<-0.019505,0.089144,0.94387>;
#declare P105  = Scale*<-0.019758,0.090594,0.95376>;
#declare P106  = Scale*<-0.020011,0.092044,0.96365>;
#declare P107  = Scale*<-0.020264,0.093495,0.97354>;
#declare P108  = Scale*<-0.020516,0.094945,0.98344>;
#declare P109  = Scale*<-0.020767,0.096396,0.99333>;

union {

    cylinder{

             <0,-100,0>,
             <0,100,0>,
             0.1
             texture { pigment {Red} }


             }


    cylinder{

             <-100,0,0>,
             <100,0,0>,
             0.1
             texture { pigment {Green} }


             }




    cylinder{

             <0,0,-100>,
             <0,0,100>,
             0.1
             texture { pigment {Blue} }


             }


    sphere_sweep {
                    b_spline,
                    109
                    P1,Radius,
                    P2,Radius,
                    P3,Radius,
                    P4,Radius,
                    P5,Radius,
                    P6,Radius,
                    P7,Radius,
                    P8,Radius,
                    P9,Radius,
                    P10,Radius,
                    P11,Radius,
                    P12,Radius,
                    P13,Radius,
                    P14,Radius,
                    P15,Radius,
                    P16,Radius,
                    P17,Radius,
                    P18,Radius,
                    P19,Radius,
                    P20,Radius,
                    P21,Radius,
                    P22,Radius,
                    P23,Radius,
                    P24,Radius,
                    P25,Radius,
                    P26,Radius,
                    P27,Radius,
                    P28,Radius,
                    P29,Radius,
                    P30,Radius,
                    P31,Radius,
                    P32,Radius,
                    P33,Radius,
                    P34,Radius,
                    P35,Radius,
                    P36,Radius,
                    P37,Radius,
                    P38,Radius,
                    P39,Radius,
                    P40,Radius,
                    P41,Radius,
                    P42,Radius,
                    P43,Radius,
                    P44,Radius,
                    P45,Radius,
                    P46,Radius,
                    P47,Radius,
                    P48,Radius,
                    P49,Radius,
                    P50,Radius,
                    P51,Radius,
                    P52,Radius,
                    P53,Radius,
                    P54,Radius,
                    P55,Radius,
                    P56,Radius,
                    P57,Radius,
                    P58,Radius,
                    P59,Radius,
                    P60,Radius,
                    P61,Radius,
                    P62,Radius,
                    P63,Radius,
                    P64,Radius,
                    P65,Radius,
                    P66,Radius,
                    P67,Radius,
                    P68,Radius,
                    P69,Radius,
                    P70,Radius,
                    P71,Radius,
                    P72,Radius,
                    P73,Radius,
                    P74,Radius,
                    P75,Radius,
                    P76,Radius,
                    P77,Radius,
                    P78,Radius,
                    P79,Radius,
                    P80,Radius,
                    P81,Radius,
                    P82,Radius,
                    P83,Radius,
                    P84,Radius,
                    P85,Radius,
                    P86,Radius,
                    P87,Radius,
                    P88,Radius,
                    P89,Radius,
                    P90,Radius,
                    P91,Radius,
                    P92,Radius,
                    P93,Radius,
                    P94,Radius,
                    P95,Radius,
                    P96,Radius,
                    P97,Radius,
                    P98,Radius,
                    P99,Radius,
                    P100,Radius,
                    P101,Radius,
                    P102,Radius,
                    P103,Radius,
                    P104,Radius,
                    P105,Radius,
                    P106,Radius,
                    P107,Radius,
                    P108,Radius,
                    P109,Radius

                  tolerance 0.1
                  texture{ pigment{ color rgb<0.69,0.99,0.15>}
      finish { phong 1
       ambient 0.3
     }
     }

     }
      rotate -90*x
      rotate 150*y

     translate -20*y


}// end of union


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Attachments:
Download 'povrayprob.png' (134 KB)

Preview of image 'povrayprob.png'
povrayprob.png


 

From: jr
Subject: Re: Sphere sweep appears to be thicker at the base and thinner at the tip
Date: 23 Sep 2022 14:45:00
Message: <web.632dfd7ce9427508ecf5a77b6cde94f1@news.povray.org>
hi,

"Aj" <nomail@nomail> wrote:
> Hello everyone,
>
> I am trying to fix this problem with my sphere sweep object ...
> If you look at the base of the object and compare it with the tip, you will
> notice that the tip appears to be thinner than the base, any suggestion on how
> to fix this problem would be very helpful.

two things I can think of:
  (a) use an orthographic type camera.
  (b) ensure the points lie in a plane wrt perspective camera.


regards, jr.


Post a reply to this message

From: Thomas de Groot
Subject: Re: Sphere sweep appears to be thicker at the base and thinner at the tip
Date: 24 Sep 2022 07:07:11
Message: <632ee4df$1@news.povray.org>
Op 23-9-2022 om 20:39 schreef jr:
> hi,
> 
> "Aj" <nomail@nomail> wrote:
>> Hello everyone,
>>
>> I am trying to fix this problem with my sphere sweep object ...
>> If you look at the base of the object and compare it with the tip, you will
>> notice that the tip appears to be thinner than the base, any suggestion on how
>> to fix this problem would be very helpful.
> 
> two things I can think of:
>    (a) use an orthographic type camera.
>    (b) ensure the points lie in a plane wrt perspective camera.
> 

I agree with jr. I think this is a perspective "problem" as I do not 
really "see" the sphere sweep getting thinner.

-- 
Thomas


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