Oleguer wrote:
> Yes, Ok I had read this web page. Now I used this code "+SR0.44 +ER0.61
> +SC0.58 +EC0.75". The main picture is in 1280x960.
> 1280/25= 51'2 and 960/25= 38'4.
> How can I now if my square is 51'2 width and 38'4 height? Because I supose
> that if the square is biger than 51'1x38'4 I can't upload it.
>
> How do you know the other number that appear on the exemple? ( +EC0.640625
> and +ER0.455469).

You're required to render 1/25 of the area of your original image;
that means that the difference between your +sc/+ec and +sr/+er has to
be less than, or equal to, 0.2.  That 0.2 is simply 1/5, which in turn
stems from the 1/25 area requirement: 1/5*1/5 for the width and height
respectively gives you an area that is 1/25 of the original).  That's
where the other numbers come from.

Hint: you can 'try out' your detail view by creating in your image
editor a movable square (or a crop window) with size 256x192.
Anything you see of your main image _through this rectangle_ is
suitable (once rendered at proper resolution) as your detail image(s).

Please notice that your 1280/25 calculation is kind of "wrong" (it
would give you an area that is 625th of the main image, which is 25
times smaller than required; it's OK by the rules, but it seems to me
that this is not what you're attempting! :))

The +sc/+ec/+sr/+er you give yield:
ec - sc = 0.75 - 0.58 = 0.17, which is less than 0.2, therefore ok.
er - sr = 0.61 - 0.44 = 0.17, which is less than 0.2, therefore ok.
This would give you a detail image whose area is 0.17*0.17 = 0.0289 < 0.04,
so everything's fine!  (0.04 = 1/25)

To render the detail view with POV-Ray you would say

+sc0.58 +ec0.75 +sr0.44 +er0.61 +w6400 +h4800

and the resulting detail image would have pixel dimensions 1088x816
after the margins are cropped out, which is just enough as required by
the rules ("The detail views have to be at least 800 pixels wide and
high").  Notice that you'd probably want to have +a on too, because
you're not going to scale this image down.

It seems to me you have actually done all of this, or at least
considered it, so are you still having a problem?  If you're seeing
the details you WANT in your detail images, and haven't made a typo in
posting your parameters, then everything should be OK.

DON'T LET ME GET YOU CONFUSED NOW!  You're doing fine, here's just how
you would render the same detail image in 1280x960.

1280/0.17 = 7529,411
960/0.17 = 5647,059
--> +sc0.58 +ec0.75 +sr0.44 +er0.61 +w7530 +h5648

--
jussi.kantola