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Hi,
Something is not really clear !! It seems you need a specific camera
(spherical or mirrored ball) to create spherical-360 type pictures.
Look at http://www.debevec.org/Probes/ for pic.
-------------
Some pic are done with professional tools (cameras, software) and are done
using 8 or more pictures to have a full panoramic view.
But some pic are done using only one shot and the result is still correct.
-------------
Now, all the pic I have are rectangular shape (well, the basic shape) which
is not convenient for a spherical mapping. My question : is there a way
to simulate this spherical effect using a camera effect in POV 3.5 (such as
Fish-eye ?) or using an other software (Photoshop, COrel, others) or am I
obliged to buy a specific mirrored sphere camera ??
Your answer would appreciated.
Tommy
-----------------
<a href="http:/www.webkenya.com/">www.webkenya.com</a>
Promote web development in Africa
WWW - World Wide Web or Western Wide Web
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For information, it seems that any chrome ball would do as long as the ball
is correctly aligned with the camera axis. Need to give a try using a Xmas
ball and make a single_image_light_probe.
I found a page on how to do a totally fake HRDI using chrome ball (the
rendering is done using Maya and his env_file type) but it is necessary to
retouch the hightlights (which is not the case using HRD.format pictures) :
<a
href="http://www.3dluvr.com/pixho/tutorials/highLights/page2.htm">http://www.3dluvr.com/pixho/tutorials/highLights/page2.htm
</a>
That's it....
Tommy
--------------
<a href="http://www.webkenya.com/">http://www.webkenya.com/
</a>
Promote web development in Africa
WWW - World Wide Web or Western Wide Web ??
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"lieven_ke" <lie### [at] yahoo fr> wrote in message
news:web.3e1946638f98ce8434cdce030@news.povray.org...
> For information, it seems that any chrome ball would do as long as the
ball
> is correctly aligned with the camera axis. Need to give a try using a
Xmas
> ball and make a single_image_light_probe.
>
> I found a page on how to do a totally fake HRDI using chrome ball (the
> rendering is done using Maya and his env_file type) but it is necessary to
> retouch the hightlights (which is not the case using HRD.format pictures)
:
> http://www.3dluvr.com/pixho/tutorials/highLights/page2.htm
Interesting stuff, I haven't delved into any about HDRI yet. Thanks for
sharing that about the Ornament Photoshop filter; used a image done with the
'spherical' projection type camera just to see if my PS 4.0 LE (came with
digital camera) would work okay, which it does seem to.
Oh, and maybe that's all you needed to know before. That there is a
spherical camera in POV-Ray. I'm just unsure about how to set this kind of
thing up correctly, if it can be at all. From the looks of it I'd say you
need to use the 'fisheye', but if trying to convert a photo in POV then it
might not be completely possible. I just don't know.
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Hi,
To learn more, go to Paul Debevec's site. He has HDRShop online for
download.
There are several options, techniques, etc. available. The program, as the
name
might imply, is a versatile tool for converting images to/from HDR; creating
HDRI, creating light probes and mirror-balls (while they appear similar,
their
roles are different) and converting probes and balls to images. One of the
techniques is converting a series of standard photos to a software light
probe.
Sources of 3" ball bearings are mentioned, use ,and drawbacks of, lawn
ornament
mirror balls.
Spend a couple of days studying the site and the material, work with
HDRShop and you'll have a better idea of what you need and what options are
open to you.
My question? Does MLPOV give us access to all the features of HDRI
and HDRShop? Reflections, environmental lighting, motion blur, full
HDRI file format compatibility?
Regarding the use of Povray spherical uv-mapping, the idea is to
map an environment on a sphere, capturing what could be considered,
both a vertical and horizontal panoramic map, combined. Just think
of an image of the earth globe with all the lines of latitude and longitude
and you will get an idea of the relation between panoramic images
and spherical surfaces.
HDRShop can consruct a light probe using a photo-cross. The cross-shape
defines the shape of a cube when opened and flattened. If you develop the
math, you can transform an image mapped on a cube to a sphere and back.
This is true for
any regular polyhedron (3d polygon).
As the number of sides of a polygon increases, the figure approximates
a circle. A dodecagon more closely resembles a circle than a square.
The same is true for polyhedra. The more surfaces, the closer the
approximation of a sphere. It may be intuitively obvious that the more
closely a figure approaches a sphere, the less distortion involved.
Knowing this, you can deduce that a cube is almost, but not quite, the
minimum figure needed to map an image to a sphere and almost the greatest
distortion. This distortion is taken into account in the software.
The choice of the cube over, e.g. a dodecahedron, is that
cameras take quadrangle shaped (4-sides, usually not square) photographs.
Anyway, study the material on the site and you will begin to understand
what you need to know.
There is a mention of and a link to, a website with a
beginner/non-science based explanation. I've seen it and it does a good job
as an introduction to HDR.
Jim Julian
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The link is posted in the General Discussion forum, dated Jan 3, 2003.
Jim Julian
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"Jim" <jul### [at] preferredcom> wrote in message
news:web.3e1aef618f98ce8448c6527f0@news.povray.org...
>
> To learn more, go to Paul Debevec's site. He has HDRShop online for
> download.
> Spend a couple of days studying the site and the material, work with
> HDRShop and you'll have a better idea of what you need and what options
are
> open to you.
Thanks for that info. And here is that URL for anyone else who might be
interested.
http://www.debevec.org/
> My question? Does MLPOV give us access to all the features of HDRI
> and HDRShop? Reflections, environmental lighting, motion blur, full
> HDRI file format compatibility?
I had those same questions. Judging by the HTML Help it looks like only
'ambient' governs the outcome so perhaps that means just a tie-in with
luminance. Just now got MLPov 0.82 and I've been skipping over the talk in
p.u.p. so it's completely new to me.
> HDRShop can consruct a light probe using a photo-cross. The cross-shape
> defines the shape of a cube when opened and flattened. If you develop the
> math, you can transform an image mapped on a cube to a sphere and back.
> This is true for
> any regular polyhedron (3d polygon).
> As the number of sides of a polygon increases, the figure approximates
> a circle. A dodecagon more closely resembles a circle than a square.
Yes, I understand the principle. Well, considering Geometry was my worst
subject in school it's a wonder I can do anything in POV-Ray sometimes.
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