OK, forget about this issue of non-used 3D textures guys ! This was due to a
stupid mistake:
I was assigning a sampler with a not yet rendered image!
Manu.
2010/8/6 Emmanuel Roche <roche.emman...@gmail.com>
> Hi guys !
>
> The solution I suggested to myself, actually works !
>
> So, if someone needs to render to a 3D image one day, one available option
> is to attach slices of the target images as mentioned below.
>
> To get those slices I used some code like (where z is the slice to render
> to)
>
> *osg::Image* SceneTools::get3DImageSlice(osg::Image * src, int z)
> {
> // Create a new image:
> osg::Image* img = new osg::Image();
> int ww = src->s();
> int hh = src->t();
> unsigned char* data = src->data(0,0,z);
> img->setImage (ww, hh, 1, src->getInternalTextureFormat(),
> src->getPixelFormat(), src->getDataType(), data, osg::Image::NO_DELETE,
> src->getPacking());
>
> return img;
> }*
>
>
> Now I have another issue related to those 3D texture/images usage:
>
> I'm trying to copy a 3D Texture/image into another 3D texture/image with
> GLSL. And for a reason I cannot explain this is just not working... :-(
>
> I have the following setup:
>
>
> - created a target 3D image to hold the copy result.
> - create multiple cameras, with multiple color attachment (one camera
> for slice of the target image), each camera has the proper "slice" uniform
> interger.
> - Assigned the source 3D image as a SAMPLER_3D uniform on a parent
> group for all the cameras.
> - Applied a shader on the parent group for all the cameras to just copy
> the source image slice into the target image slice...
>
>
> ==> Is there something I could be missing here ?
>
> Just let me know if you need some code to have a better idea of what I'm
> doing (but almost everything is written in Lua).
>
>
> ==> One very strange thing about this is: if I use a 2D source image
> instead of a 3D source image, everything works just fine ! [I can for
> instance use the slice index to fade the input 2D image, and thus get a
> valid resulting 3D image with different slices].
>
>
> Any help would really be appreciated here :-)
>
> Cheers!
>
> Manu.
>
>
> 2010/8/4 Emmanuel Roche <roche.emman...@gmail.com>
>
>> Concerning this problem, I'm wondering if I could use the following
>> solution:
>>
>> 1. Create a "master" 3D image, and allocate it;
>> 2. Since attaching 2D images to a camera would not require any face
>> argument, I could create "sub" images, one per z slice of the master camera,
>> and use setImage with an offset data pointer in the master image data...
>> 3. Then assign those sub images to each camera I'm using to render the
>> complete 3D image.
>>
>> Would this work as expected ?? Or would attaching an image to a camera
>> actually somehow reallocate the image data ??? (and thus we would not be
>> able to write the slice data into the master image data).
>>
>> I hope, those explanations are clear enough :-)
>>
>> Manu.
>>
>>
>> 2010/8/4 Emmanuel Roche <roche.emman...@gmail.com>
>>
>> Hi everyone,
>>>
>>> I'm currently trying to generate some 3D images in an OSG based app.
>>>
>>> I've read the previous discussions on the OSG forums concerning the 3D
>>> texture rendering, but this doesn't help in my situation. What I really need
>>> is *3D image* rendering not *3D texture* rendering.
>>>
>>> More explanations:
>>>
>>> * One can attach an osg::Image or an osg::Texture to the color buffer of
>>> a given camera. But one can only specify the "face" argument for textures:
>>>
>>> *void attach <http://a00098.html#a496ed6d69392c1fdb8548085900a1a87> (
>>> BufferComponent
>>> <http://a00098.html#af4d8ae808500a2f5bc9fe7b605386e74>buffer,
>>> osg::Texture <http://a00946.html> *texture, unsigned int level=0,
>>> unsigned int face=0, bool mipMapGeneration=false, unsigned int
>>> multisampleSamples=0, unsigned int multisampleColorSamples=0)
>>>
>>> void attach <http://a00098.html#a4124951a5032de595c5d28d0cc5e87a3> (
>>> BufferComponent
>>> <http://a00098.html#af4d8ae808500a2f5bc9fe7b605386e74>buffer,
>>> osg::Image <http://a00389.html> *image, unsigned int
>>> multisampleSamples=0, unsigned int multisampleColorSamples=0)
>>>
>>> ** So,
>>> - if I attach a 3D image directly to the camera, the depth of the image
>>> is not taken into account, and all the image "slices" will contain the same
>>> result.
>>> - if I attach a Texture3D object, whether I assign it an underlying
>>> image doesn't matter: the content of the "texture" cannot be retrieved with
>>> the assigned image...
>>>
>>> Is there something I'm missing here ? Did someone already successfully
>>> render to a 3D texture *AND* wrote that texture to a file for instance
>>> ??
>>>
>>> Or is there a way to retrieve the content of a 3D texture into a 3D image
>>> (I guess retrieving the texture data from the graphic card somehow ?) [I'm
>>> not very good at pure OpenGL considerations, thus the question :-) ].
>>>
>>> Cheers! Thanks for your help guys!
>>>
>>> Manu.
>>>
>>>
>>
>
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