POV-Ray : Newsgroups : povray.general : Animated can questions Server Time
2 Nov 2024 06:15:57 EDT (-0400)
  Animated can questions (Message 1 to 4 of 4)  
From: Xplo Eristotle
Subject: Animated can questions
Date: 19 Feb 2000 19:17:20
Message: <38AF337A.637C7D91@unforgettable.com>
First, have a look at this:

http://espacesux.members.easyspace.com/anicanfinal/animation1.html
http://espacesux.members.easyspace.com/anicanfinal/animation2.html
http://espacesux.members.easyspace.com/anicanfinal/animation3.html

(The pages are essentially identical; higher numbers denote choppier animation.)

- The shading on the can flickers pretty badly. The frames were rendered
in MegaPOV-Ray with radiosity turned on and left at the default
settings; could patchy radiosity be the reason for the flickering? Would
better radiosity settings eliminate the flicker?

- To eliminate perspective distortion, the camera was backed off,
rendering was limited to a small area around the can, and the frames
were rendered at 1920 x 1440 to provide a "zoom" effect and get the can
itself back up to the size I wanted it to be. When I went back to crop
the images in Photoshop, I found that in each frame, the can seemed to
be displaced a random amount (say, up to about 10 px in each direction)
even though the only variable being altered was the amount of bending; I
had to synch them all by hand before I could create the animation.
Anyone have any idea why this might be?

I can provide the source code if it's needed.

-- 
Xplo Eristotle
http://start.at/xplosion/

"Error has no rights." - Tomas de Torquemada


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From: Chris Huff
Subject: Re: Animated can questions
Date: 19 Feb 2000 19:53:15
Message: <chrishuff_99-B5C8D1.19540419022000@news.povray.org>
In article <38AF337A.637C7D91@unforgettable.com>, 
inq### [at] unforgettablecom wrote:

> - The shading on the can flickers pretty badly. The frames were rendered
> in MegaPOV-Ray with radiosity turned on and left at the default
> settings; could patchy radiosity be the reason for the flickering? Would
> better radiosity settings eliminate the flicker?

The radiosity might be the cause, maybe increase the number of test rays 
shot...I am not very experienced with the parameters though.


> - To eliminate perspective distortion, the camera was backed off,
> rendering was limited to a small area around the can, and the frames
> were rendered at 1920 x 1440 to provide a "zoom" effect and get the can
> itself back up to the size I wanted it to be.

This seems like an awful lot of trouble...couldn't you just use an 
orthographic camera or a small angle value with the perspective camera?


> When I went back to crop the images in Photoshop, I found that in 
> each frame, the can seemed to be displaced a random amount (say, up 
> to about 10 px in each direction) even though the only variable being 
> altered was the amount of bending; I had to synch them all by hand 
> before I could create the animation. Anyone have any idea why this 
> might be?

It might be helpful to know how you are producing the can...torus 
section? Object Bender include? Some other method?

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/


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From: Xplo Eristotle
Subject: Re: Animated can questions
Date: 20 Feb 2000 13:22:07
Message: <38B031B7.B843514A@unforgettable.com>
Chris Huff wrote:
> 
> In article <38AF337A.637C7D91@unforgettable.com>,
> inq### [at] unforgettablecom wrote:
> 
> > - To eliminate perspective distortion, the camera was backed off,
> > rendering was limited to a small area around the can, and the frames
> > were rendered at 1920 x 1440 to provide a "zoom" effect and get the can
> > itself back up to the size I wanted it to be.
> 
> This seems like an awful lot of trouble...couldn't you just use an
> orthographic camera or a small angle value with the perspective camera?

Hadn't occurred to me, to be honest. ^^  I don't mess with the camera
much, though I suppose I ought to.

> > When I went back to crop the images in Photoshop, I found that in
> > each frame, the can seemed to be displaced a random amount (say, up
> > to about 10 px in each direction) even though the only variable being
> > altered was the amount of bending; I had to synch them all by hand
> > before I could create the animation. Anyone have any idea why this
> > might be?
> 
> It might be helpful to know how you are producing the can...torus
> section? Object Bender include? Some other method?

Object Bender. The can is made up of a cylinder and a couple of lathes
for the endcaps.

-- 
Xplo Eristotle
http://start.at/xplosion/

"Error has no rights." - Tomas de Torquemada


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From: Chris Colefax
Subject: Re: Animated can questions
Date: 21 Feb 2000 17:50:15
Message: <38b1c127@news.povray.org>
Xplo Eristotle <inq### [at] unforgettablecom> wrote:
> Object Bender. The can is made up of a cylinder and a couple of lathes
> for the endcaps.

I haven't had the chance to check the URL's you posted, so I can only offer
wild guesses!  It sounds like the flickering might well be related to the
radiosity - the easiest way to confirm that would be to render without
radiosity and see the difference.

The "jumping" around is possibly a result of the way you are using the
Object Bender: are you sure the can is centered the way you wish, given the
object_axis1 and object_axis2 vectors you specified?  Otherwise, increasing
the bend_smoothness value will give better results (as almost always, at the
cost of rendering time).  If you like, feel free to email me the code you
are using with the include file and I'll see what I can deduce...


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