*Another problem, *
If I take an image as a texture, OpenSG will fail to read some large images,
for instance, with the size of 1635x2573. But if I take them as foreground,
they can show correctly.
2009/8/10 Jie Liu <[email protected]>
> Hi,
>
> I want to use OpenSG do display about 150 images located in a given
> directory.
> For each time, I show one of them, and I press left key or right key to
> nevigate backward or forward. All images should align center, keep their
> width/height (w/h) ratio and they will fit to the width or height of the
> window according to the value of w/h ratio.
>
> I now have three solutions for this purpose.
> a). take an image as a background object. The problem is OpenSG will auto
> scale the image to the window area for me. But as I must keep the
> width/height ratio of the image, I give up.
>
> b). take an image as a foreground object, the problem is I can only appoint
> its bottom-left position. There seems no parameters for me to scale its
> size. Below are my code to do this
> ===================================================================
> ImagePtr tImage = Image::create();
> *tImage->read(file_name[index]);* *// I change the value of index to
> display different images. Images are loaded dynamically according to their
> names*
>
> ImageForegroundPtr ptrImgForeground = ImageForeground::create();
> beginEditCP(ptrImgForeground);
> {
> * ptrImgForeground->addImage(tImage, Pnt2f(0.0, 0)); // Can I
> assign a bounding box for an image? Or do I have to manually scale the image
> first?*
> }
> endEditCP(ptrImgForeground);
>
> * g_ptrViewport->getMFForegrounds()->push_back(ptrImgForeground); *
> *// push_back is to add a new image to the queue, OpenSG will try to
> render all images in the queue and this will slow down the rendering speed
> obviously. But I only want to display a single image at one time. So what is
> the right and efficient way to replace the current foreground image?
> *================================================================
>
> c). Take an image as a texture material, and attach it to a Quad primitive.
> ================================================================
> ImagePtr tImage = Image::create();
> tImage->read(file_name[index]);
>
> beginEditCP(g_ptrGeoTex);
> g_ptrGeoTex->setImage(tImage); *// g_ptrGeoTex is a globle variable,
> its type is SimpleTexturedMaterialPtr*
> endEditCP(g_ptrGeoTex);
>
> beginEditCP(g_ptrGeoQuad);
> g_ptrGeoQuad->setMaterial(g_ptrGeoTex);* // I found the
> setMaterial process will be very very slow, how can I accelerate it?*
> endEditCP(g_ptrGeoQuad);
> ================================================================
>
> So, what is your suggestion to write such a program? I also want to load
> all iamges at the begining of the program and store them in vectors
> (vector<ImagePtr>, and vector<SimpleTexturedMaterialPtr>), but the program
> crashed while switching the image. What is the right way to read and store
> all image data?
>
> The email is a little long, I hope it will not bother you too much~~
>
> Thanks
>
> --
> Jie Liu
> Visualization Research Group
> Center for Information Science, School of EECS,
> Room 2104, Science Building No.2,
> Peking University, Beijing 100871, China
>
>
--
Jie Liu
Visualization Research Group
Center for Information Science, School of EECS,
Room 2104, Science Building No.2,
Peking University, Beijing 100871, China
------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day
trial. Simplify your report design, integration and deployment - and focus on
what you do best, core application coding. Discover what's new with
Crystal Reports now. http://p.sf.net/sfu/bobj-july
_______________________________________________
Opensg-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/opensg-users
