POV-Ray : Newsgroups : povray.general : flattened curve Server Time
26 Nov 2022 10:53:50 EST (-0500)
  flattened curve (Message 1 to 6 of 6)  
From: David Kraics
Subject: flattened curve
Date: 15 Sep 2022 18:50:00
Message: <web.6323aad77967e8641c1b6180a57e0@news.povray.org>
trying to render an airplane and I need a more subtle curve. let me explain.
Imagine a box that is one unit high and four units wide. Now place, in front of
it, a quarter of a cylinder with a radius of one unit. The center of the quarter
cylinder is at the top right corner of the box. The curve then travels, from the
bottom right corner, to the top left corner, thanks to a 4 scale in the x
direction. How do I make that curve more subtle, to closer approach an almost
straight line between those two corners?


Post a reply to this message

From: Thomas de Groot
Subject: Re: flattened curve
Date: 16 Sep 2022 02:29:49
Message: <632417dd$1@news.povray.org>
Op 16/09/2022 om 00:44 schreef David Kraics:
> trying to render an airplane and I need a more subtle curve. let me explain.
> Imagine a box that is one unit high and four units wide. Now place, in front of
> it, a quarter of a cylinder with a radius of one unit. The center of the quarter
> cylinder is at the top right corner of the box. The curve then travels, from the
> bottom right corner, to the top left corner, thanks to a 4 scale in the x
> direction. How do I make that curve more subtle, to closer approach an almost
> straight line between those two corners?
> 

Probably not what you want but straightforward:

Solution 1: Scale down y by a factor of 10 (for instance) in both the 
box and quarter cylinder: scale <1, 0.1, 1>.

Solution 2: Scale up x by a factor 10 in both the box and quarter 
cylinder: scale <10, 1, 1>.

You can always resize your object afterwards.


-- 
Thomas


Post a reply to this message

From: Bald Eagle
Subject: Re: flattened curve
Date: 16 Sep 2022 06:30:00
Message: <web.63244f1d4192552b1f9dae3025979125@news.povray.org>
"David Kraics" <bar### [at] aolcom> wrote:
> trying to render an airplane and I need a more subtle curve. let me explain.
> Imagine a box that is one unit high and four units wide. Now place, in front of
> it, a quarter of a cylinder with a radius of one unit. The center of the quarter
> cylinder is at the top right corner of the box. The curve then travels, from the
> bottom right corner, to the top left corner, thanks to a 4 scale in the x
> direction. How do I make that curve more subtle, to closer approach an almost
> straight line between those two corners?

Totally not following your explanation.

Maybe use a spline to define your curve, and a prism to make the entire object?


Post a reply to this message

From: Alain Martel
Subject: Re: flattened curve
Date: 16 Sep 2022 09:32:48
Message: <63247b00$1@news.povray.org>
Le 2022-09-15 à 18:44, David Kraics a écrit :
> trying to render an airplane and I need a more subtle curve. let me explain.
> Imagine a box that is one unit high and four units wide. Now place, in front of
> it, a quarter of a cylinder with a radius of one unit. The center of the quarter
> cylinder is at the top right corner of the box. The curve then travels, from the
> bottom right corner, to the top left corner, thanks to a 4 scale in the x
> direction. How do I make that curve more subtle, to closer approach an almost
> straight line between those two corners?
> 

Apparently, you want to model the wings.

I'd start with that cylinder, but apply some uneven scaling. It could be 
something like :
cylinder{End1, End2, 1 scale<5,1,1>}

A larger value will result in flatter top and bottom parts.

Another option would be to use a prism for the wings. Then, it's just a 
question of choosing the interpolation method that work best for your 
needs. Try the bicubic spline. Maybe more cumbersome, but, you'll need 
only one object for the whole wing.


Post a reply to this message

From: kurtz le pirate
Subject: Re: flattened curve
Date: 17 Sep 2022 06:39:44
Message: <6325a3f0$1@news.povray.org>
On 16/09/2022 00:44, David Kraics wrote:
> trying to render an airplane and I need a more subtle curve. let me explain.
> Imagine a box that is one unit high and four units wide. Now place, in front of
> it, a quarter of a cylinder with a radius of one unit. The center of the quarter
> cylinder is at the top right corner of the box. The curve then travels, from the
> bottom right corner, to the top left corner, thanks to a 4 scale in the x
> direction. How do I make that curve more subtle, to closer approach an almost
> straight line between those two corners?
> 


This page will surely give you ideas :
<http://www.f-lohmueller.de/pov_tut/x_sam/tec_800e.htm>


-- 
Kurtz le pirate
Compagnie de la Banquise


Post a reply to this message

From: ingo
Subject: Re: flattened curve
Date: 17 Sep 2022 09:55:00
Message: <web.6325d0a54192552b17bac71e8ffb8ce3@news.povray.org>
You may want to look into extrusions. There is a relative simple option in the
mesh macro include file or use the more complex Striscia @
https://news.povray.org/povray.binaries.utilities/thread/%3CXns94D4AF6BE46A0seed7%40news.povray.org%3E/?ttop=437912&tof
f=100

An other way to get nice curves is to use blobs. Scale them large.

ingo


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.