[osg-users] SKYBOX ?

Naomaru Itoi nao at fresvii.com
Tue Sep 2 17:34:23 PDT 2008


Hello,

I was able to put texture on TextureCubeMap, using the code by
Jean-Sebastien.  Thank you very much, again.

Now, when I try to use a 2048x2048 jpeg image for the texture, I get
this message (after viewer.run()):

  Scaling image 'skybox-1.jpg' from (2048,2048) to (512,512)

And indeed the image seems rescaled to 512x512.  It does not have the
quality of 2048x2048 image.

Is there a way to use the 2048x2048 image without rescaing?  What
component is enforcing this 512x512 restriction?

Any help shall be appreciated,

Thank you.

-
Nao


On Thu, Aug 28, 2008 at 11:42 AM, Naomaru Itoi <nao at fresvii.com> wrote:
> Dear Jean-Sebastien,
>
> Your advice worked perfectly.  Thank you very much!
>
> Date: Thu, 28 Aug 2008 08:07:59 -0400
> From: Jean-S?bastien Guay <jean-sebastien.guay at cm-labs.com>
> Subject: Re: [osg-users] SKYBOX ?
> To: OpenSceneGraph Users <osg-users at lists.openscenegraph.org>
> Message-ID: <48B6951F.8050602 at cm-labs.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Hello Nao,
>
>> I tried the following code by Jean-S?bastien, and it worked great.  Thank you!
>
> Great to know it was of some use.
>
>> - The texture on the skybox gets magnified quite largely.  If I use
>> 512x512 image as texture, my entire screen gets occupied by probably
>> 200x150 portion of it.  As a result, the image gets stretched, and the
>> quality suffers.  It is like the camera is too close to the skybox.
>> Is there any way to change this (make the skybox far from the camera)?
>
> The skybox fills the full 360x360 degree cube, and the camera is in the
> middle of it, so "making the skybox far from the camera" makes no sense.
> What you can do is increase the camera's FOV, which will make more of
> the skybox visible at one time. But really, the best idea is to use a
> higher resolution skybox image.
>
>> - It seems that texture is shown upside-down.  At least I can tell
>> positive-y image is.  I believe I can fix this by rotating the jpeg
>> image, but is there a better (or more right) way of fixing this?
>
> That's weird, the images were OK in my case, and if you're loading a
> vertical cross cubemap as I was they should be OK for you as well... If
> your vertical cross cubemaps are not in the same format as mine, you
> might have to tweak how they're oriented. You can find the code that
> extracts the faces of the vertical cross cubemap and changes the images'
> orientations in the function
>
> osg::TextureCubeMap* loadVerticalCrossCubeMap(const std::string& filename)
>
> which is in osgUtil.cpp that was sent in a later message. See where it
> says things like
>
>    zminus->flipVertical();
>
> and try out other combinations of flipVertical and flipHorizontal on the
> various cube faces until you get the right result.
>
> Hope this helps,
>
> J-S
> --
> ______________________________________________________
> Jean-Sebastien Guay    jean-sebastien.guay at cm-labs.com
>                               http://www.cm-labs.com/
>                        http://whitestar02.webhop.org/
>



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