Hello everyone

I'm working on an image for the current IRTC stills round 'Frozen 
Moment', and I'd like to indicate somehow that a particular object in 
the scene is moving. Now, motion blur would probably be ideal for this, 
but I'm using POV-Ray 3.5 and I'm not currently aware of any motion blur 
patches for it. I could try moving to MegaPOV 0.7, but I'm not sure how 
much of the scene I'd have to alter to make it compatible, and I don't 
really want to have to go down that route if I can avoid it as it's 
needless extra work.

So, are there any other ways to indicate movement of an object? 
Unfortunately it's not one that has anything that flaps or trails behind 
it. Or can one simulate motion blur with any reasonable expectation of a 
half-decent effect?

Thanks

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In article <3dcaf724$1@news.povray.org>,
 Matt Walton <mat### [at] alledoracouk> wrote:

> Unfortunately it's not one that has anything that flaps or trails behind 
> it. Or can one simulate motion blur with any reasonable expectation of a 
> half-decent effect?

You could imitate it by using multiple transparent copies of the object, 
which is how the patch actually did its work. I think transmit will give 
the most correct results in this case. The original patch kind of 
treated the body of the motion blur statement as the body of a loop, and 
parsed it several times with different clock values. Just make sure to 
set the max_trace_level high enough...

The only other way I can think of would be to somehow indicate the 
object's motion by its effect on the rest of the scene, a rubber ball 
with a falling stack of cans behind it for example. You really need 
motion blur for a realistic effect...

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> You really need motion blur for a realistic effect...

  Not in a perfectly "frozen moment"...  ;) 


-- 
Jaime Vives Piqueres

La Persistencia de la Ignorancia
http://www.ignorancia.org

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Depending on the render times, you can render multiple copies of your
scene with the object moving a little and then average them together.
The averaging part can be done in POV using image_maps and the average
pattern, so you can stay within the rules of the IIRC.

You can also only render the part of the scene where your object
appears, then use some clever (function-based, most likely) texturing
to paste it into POV - it all depends on your render times.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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Jaime Vives Piqueres wrote:
> Not in a perfectly "frozen moment"...  ;) 

Why not just post a screen shot of POV, with the 0 pph included? ;)

-- 
Tim Cook
http://empyrean.scifi-fantasy.com
mirror: http://personal.lig.bellsouth.net/lig/z/9/z993126

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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Christopher James Huff <chr### [at] maccom> wrote:
> You could imitate it by using multiple transparent copies of the object, 
> which is how the patch actually did its work.

  Wrong. The patch did not add any transparency anywhere. It simply traced
the same object several times, transforming the object with the given
transformations at each sample, and then averaged the results.

  This gives a lot more realistic result. Using semitransparent objects
will give you unrealistic results. For instance, using semitransparent
objects will make the interior of the object partially visible, which is
usually very unwanted.

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -

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In article <3dcbd026@news.povray.org>, Warp <war### [at] tagpovrayorg> 
wrote:

>   Wrong. The patch did not add any transparency anywhere. It simply traced
> the same object several times, transforming the object with the given
> transformations at each sample, and then averaged the results.

By "how the patch actually did its work" I was referring to the multiple 
copies part, which *is* what the patch did. It didn't trace one object 
multiple times, it traced multiple copies of the object.


>   This gives a lot more realistic result. Using semitransparent objects
> will give you unrealistic results. For instance, using semitransparent
> objects will make the interior of the object partially visible, which is
> usually very unwanted.

Which is why I said "most correct" results instead of "correct" results. 
Maybe I didn't make it clear enough, but this is just a way to imitate 
the blur effect without a patch.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff <chr### [at] maccom> wrote:
> It didn't trace one object 
> multiple times, it traced multiple copies of the object.

  The practical difference being...?-)

  What I meant was that it traces the object as-is, without modifying the
surface properties of the object (eg. making it partially transparent).

> Which is why I said "most correct" results instead of "correct" results. 
> Maybe I didn't make it clear enough, but this is just a way to imitate 
> the blur effect without a patch.

  It's just that from your post one could get the idea that the suggested
solution is exactly what the MegaPov patch did but just internally and a
bit faster. It's not like that.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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In article <3dcbddde@news.povray.org>, Warp <war### [at] tagpovrayorg> 
wrote:

> Christopher James Huff <chr### [at] maccom> wrote:
> > It didn't trace one object 
> > multiple times, it traced multiple copies of the object.
>   The practical difference being...?-)

You could use it as a loop, and do other stuff besides simply 
transforming the object. For example, you could make an isosurface 
changing shape or a moving texture have motion blur, or even completely 
change the type of object or remove some "copies" entirely. In normal 
usage there was little difference, though.


>   What I meant was that it traces the object as-is, without modifying the
> surface properties of the object (eg. making it partially transparent).

Right, I didn't mean to imply that it did.


>   It's just that from your post one could get the idea that the suggested
> solution is exactly what the MegaPov patch did but just internally and a
> bit faster. It's not like that.

Hmm...I didn't intend that. Sorry.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Use those elements of composition that imply movement.   An automobile
viewed head on in an orthographic projection in the exact center of the
image does **not** imply movement.

Avoid tacking blurring special effects.

"Matt Walton" <mat### [at] alledoracouk> wrote in message
news:3dcaf724$1@news.povray.org...
>
> So, are there any other ways to indicate movement of an object?
>

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