| NVidia Quadro4 980 XGL card + IDL [message #47263] |
Thu, 02 February 2006 00:01  |
raval.chintan
Messages: 54
Registered: May 2005
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Member |
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Dear All,
I am using NVidia Quadro 4 980 XGL. One can visualize stereo images
using Quad Buffer , available on this card. Proper interface
(functions) for rendering images using this buffer are given in
OpenGL.. Quad Buffer includes Left and Right Buffer ,which will be
rendered one by one.For Visulization of images one needs, shutter
glasses with infrared emitter to be connected with graphics card.
Will it be possible to render an image with use of this buffer on IDL
Draw widget? or in other way ,Will it be possible call this
interface(functions) of OpenGL through IDL?
In IDL help i found that IDL uses two type of rendering 1) Hardware
(OpenGL) 2) Software.
I also found the difference between hardware and software rendering in
IDL.
It would be fine if any one helps me in this regard.
Awaiting for Reply...
Regards,
Chintan
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47308 is a reply to message #47263] |
Fri, 03 February 2006 11:00  |
Rick Towler
Messages: 821
Registered: August 1998
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Senior Member |
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raval.chintan@gmail.com wrote:
> Karl Schultz wrote:
>> On Thu, 02 Feb 2006 00:01:57 -0800, raval.chintan wrote:
>>
>>> Dear All,
>>>
>>> I am using NVidia Quadro 4 980 XGL. One can visualize stereo images
>>> using Quad Buffer , available on this card. Proper interface
>>> (functions) for rendering images using this buffer are given in
>>> OpenGL.. Quad Buffer includes Left and Right Buffer ,which will be
>>> rendered one by one.For Visulization of images one needs, shutter
>>> glasses with infrared emitter to be connected with graphics card.
>>>
>>>
>>> Will it be possible to render an image with use of this buffer on IDL
>>> Draw widget? or in other way ,Will it be possible call this
>>> interface(functions) of OpenGL through IDL?
>> This is not supported in IDL 6.2, nor will it be in 6.3. We're getting
>> enough requests for it that it may be in a release soon.
>>
>> Although it is not documented or supported, you can make OpenGL calls from
>> C-language DLM's if you do things carefully. To do what you want, you'll
>> probably have to subclass IDLgrView with IDL code where you would override
>> the Draw method. You would also write a C DLM that calls glDrawBuffer
>> with GL_BACK_RIGHT.
>>
>> By the time IDLgrView::Draw is called, the correct GL context is in
>> place and IDL has already called glDrawBuffer with GL_BACK (implies
>> GL_LEFT as well). Your new Draw method would call the C DLM code to call
>> the superclass Draw method, call the C DLM code to set GL_BACK_RIGHT, and
>> then call the superclass Draw method again.
>
>
> If i am correct with my limited knowledge of IDL, IDLgrView class does
> not have the draw
> method. IDLgrWindow , IDLgrModel,IDLgrBuffer have draw method. Now the
> question comes that which class's draw method i should override.
> IDLgrWindow , IDLgrModel or IDLgrBuffer? Where will C dlm render the
> Left and right image? Will it be on IDL's window or on C's window?
All IDLgr* atoms have a draw method. When you call IDLgrWindow::Draw,
it in turn calls IDLgrView::Draw which in turn calls IDLgrModel::Draw
which in turn calls IDLgrPolygon::Draw and so on.
See for yourself. Create a subclass of IDLgrView and override the Draw
method like so:
pro MyView::Draw, destObject
print, 'Well I know my name is Simon, ' $
'and I like to do drawings...'
self -> IDLgrView::Draw, destObject
end
Now every time you draw this view, it will print out some text.
> It would be helpful if you can provide sample code or detailed
> explaination of your suggested technique.
>
I *strongly* suggest that you pursue the method I suggested. The method
Karl outlined isn't for the faint of heart. Especially when there is an
alternative method that will be easier to implement. There *may* be
some performance benefits to using the Stereo API but the work involved
doesn't justify pursuit of that method without at least trying my
method. IMO, of course.
But if you really want to do this the hard way, Karl posted code that
demonstrates his technique of making openGL calls from a DLM on the user
contrib site. It is in the advanced visualization section, the file is
IDL_VGL.zip.
-Rick
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47311 is a reply to message #47263] |
Fri, 03 February 2006 09:06 |
Karl Schultz
Messages: 341
Registered: October 1999
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Senior Member |
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On Thu, 02 Feb 2006 22:22:05 -0800, raval.chintan wrote:
> Karl Schultz wrote:
>> On Thu, 02 Feb 2006 00:01:57 -0800, raval.chintan wrote:
>>
>>> Dear All,
>>>
>>> I am using NVidia Quadro 4 980 XGL. One can visualize stereo images
>>> using Quad Buffer , available on this card. Proper interface
>>> (functions) for rendering images using this buffer are given in
>>> OpenGL.. Quad Buffer includes Left and Right Buffer ,which will be
>>> rendered one by one.For Visulization of images one needs, shutter
>>> glasses with infrared emitter to be connected with graphics card.
>>>
>>>
>>> Will it be possible to render an image with use of this buffer on IDL
>>> Draw widget? or in other way ,Will it be possible call this
>>> interface(functions) of OpenGL through IDL?
>>
>> This is not supported in IDL 6.2, nor will it be in 6.3. We're getting
>> enough requests for it that it may be in a release soon.
>>
>> Although it is not documented or supported, you can make OpenGL calls from
>> C-language DLM's if you do things carefully. To do what you want, you'll
>> probably have to subclass IDLgrView with IDL code where you would override
>> the Draw method. You would also write a C DLM that calls glDrawBuffer
>> with GL_BACK_RIGHT.
>>
>> By the time IDLgrView::Draw is called, the correct GL context is in
>> place and IDL has already called glDrawBuffer with GL_BACK (implies
>> GL_LEFT as well). Your new Draw method would call the C DLM code to call
>> the superclass Draw method, call the C DLM code to set GL_BACK_RIGHT, and
>> then call the superclass Draw method again.
>
>
> If i am correct with my limited knowledge of IDL, IDLgrView class does
> not have the draw
> method. IDLgrWindow , IDLgrModel,IDLgrBuffer have draw method. Now the
> question comes that which class's draw method i should override.
> IDLgrWindow , IDLgrModel or IDLgrBuffer? Where will C dlm render the
> Left and right image? Will it be on IDL's window or on C's window?
I did say you need to do it for IDLgrView. Actually, IDLgrScene would
probably be more correct, but I tend to not use Scenes or Viewgroups in
anything but the more complex programs.
You can't do this by overriding a destination (Window or Buffer) object's
Draw method because you need to sneak in the glDrawBuffer call *after* IDL
issued it for the destination object and before it actually starts drawing
objects.
You could do it at the grModel level, but the glDrawBuffer call would not
take effect until IDL reached that Model in the scene graph, so anything
before that would end up in the wrong buffer.
So Scene or View is the Right Place.
The C DLM does nothing but slip in a call to glDrawBuffer at the right
place. IDL contines to render as it did before, but just to the GL buffer
specified in the glDrawBuffer call.
glDrawBuffer just sets GL state (the current draw buffer). It does not
actually perform a Draw on a Buffer.
>
> It would be helpful if you can provide sample code or detailed
> explaination of your suggested technique.
okay....
I don't have any stereo hardware at the moment. So, I'm going to make a
grView subclass that renders the scene graph twice into the same
destination object, but with a slight offset the second time so that you
can see the second rendering.
Notice that only because I'm doing this to the same GL buffer, I need to
keep the view from erasing on the second draw, so I set the TRANSPARENT
flag. You would not do this in the real stereo case because you would want
to go ahead and paint the view with the view background color in the
"other" (right) stereo buffer.
pro IDLstereoView::Draw, dest
self->IDLgrView::Draw, dest
self->GetProperty, VIEWPLANE_RECT=vpr, TRANSPARENT=trans
vprsave = vpr
vpr[0] += 0.1
self->SetProperty, VIEWPLANE_RECT=vpr, TRANSPARENT=1
;; call DLM that calls glDrawBuffer(GL_BACK_RIGHT) here!
self->IDLgrView::Draw, dest
self->SetProperty, VIEWPLANE_RECT=vprsave, TRANSPARENT=trans
end
pro IDLstereoView__define
struct = { IDLstereoView, $
INHERITS IDLgrView}
end
test program:
pro test_stereo_view
oWin = OBJ_NEW('IDLgrWindow')
oView = OBJ_NEW('IDLstereoView')
oModel = OBJ_NEW('IDLgrModel')
oPolyline = OBJ_NEW('IDLgrPolyline', [[-0.9,-0.9],[0.9,0.9]])
oView->Add, oModel
oModel->Add, oPolyline
oWin->Draw, oView
end
All you'd have to do to try the stereo stuff is to code a DLM C procedure
that does absolutely nothing else execpt:
glDrawBuffer(GL_BACK_RIGHT);
and call it from where I indicated above. You don't need to "put things
back" by calling glDrawBuffer(GL_BACK_LEFT) after the second draw because
IDL will do that on the next draw. But it may be good form to do so.
Oh, and you'd have to figure out the eye transform stuff (see other posts
in this thread) and how to activate your hardware to go into stereo
mode.
Please refer to the External Design Guide and the accompanying
samples for more information on the DLM.
Karl
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47332 is a reply to message #47263] |
Thu, 02 February 2006 13:40 |
Dick Jackson
Messages: 347
Registered: August 1998
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Senior Member |
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"Rick Towler" <rick.towler@nomail.noaa.gov> wrote in message
news:<drtntg$135$1@news.nems.noaa.gov>...
>
> You would be better off learning how to control the shutter glasses from
> within IDL (hack them to run off of the serial port?) and then modify
> IDL's IDLgrView/IDLgrModel parameters to render the left and right eye
> views as you run your glasses. My camera object makes rendering the left
> and right eye views easy. It also has the added bonus of allowing you to
> easily manipulate your model as you view it.
>
> http://www.acoustics.washington.edu/~towler/RHTgrCamera.html
>
> I've played around with this using multiple monitors, Saran wrap
> ( http://www.sas.org/E-Bulletin/2003-06-20/labNotesAS/body.htm l) and
> polarized glasses. I have also used multiple projectors with polarizing
> lenses. It can be tricky setting up the views/monitors/viewer so you get
> a "natural" 3d effect but it can be done.
>
> Dick Jackson has worked with this as well and has been quite successful.
> He could probably give you more tips on setting up views if you decided to
> go this route.
This OpenGL site helped me to get the exact setup for the two views.
On Stereo Viewing:
http://www.opengl.org/resources/tutorials/sig99/advanced99/n otes/node24.html
Section on setting up transforms:
http://www.opengl.org/resources/tutorials/sig99/advanced99/n otes/node26.html
I think Rick's Camera object is great and can easily give you two views from
different eye positions looking at the same point in space. (if you use this
to generate the stereo views, that last link refers to this as the
"alternative, but less correct, method")
Be aware that for perfect stereo rendering, the views should be rendered
from different positions (eye positions) looking in the *same* direction
(parallel) and then offset on the viewing device so that each eye's
"straight ahead" point is directly in front of that eye. Note that this is
dependent on display resolution and distance from the user to the display.
Tricky business, but the results can be tremendous!
Cheers,
--
-Dick
Dick Jackson / dick@d-jackson.com
D-Jackson Software Consulting / http://www.d-jackson.com
Calgary, Alberta, Canada / +1-403-242-7398 / Fax: 241-7392
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47403 is a reply to message #47263] |
Thu, 09 February 2006 10:52 |
Rick Towler
Messages: 821
Registered: August 1998
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Senior Member |
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Chintan,
While I very much respect doing it the hard way (the journey is almost
always more enjoyable than the destination), I'll second my offer, and
sweeten the deal.
I have modified my camera object so it now offers stereo support. At
this time it has only been tested with shutter glasses but would work
equally well with dual-monitor or dual-projector setups.
Some caveats:
As I suggested in a previous email, the shutter glasses are controlled
via the serial port, *not* the glasses port on your video card. This is
good, in that it allows anyone with access to the glasses to use them,
but bad in that you have to build a little circuit to interface the
glasses to the serial port. It is *very* simple, and costs only a few
dollars (a couple of LM301 or similar op-amps, a cap, and a couple of
resistors). This approach also allows multiple glasses to be controlled
by the pc.
The dlm I have written for controlling the glasses is for windows. If
someone wants to do this on another platform they need to modify the
dlm. It is very simple, and should be trivial.
If you are using shutter glasses, you need a good CRT monitor with a
high refresh rate. I forgot this when testing the glasses and couldn't
trace down the sync problem I was having... LCD monitors are too slow.
I have only done limited testing. Further testing needs to be done to
confirm that the asymmetric frustum projection is correct. In IDL we
don't have access to the perspective projection matrix, so I apply a
"correction" to the modelview matrix. I think this works... If it
doesn't there are other ways to fake this, just not as clean.
The code needs to be cleaned up and documented so I'm not posting it
right now but you are welcomed to a copy, along with the circuit diagram.
-Rick
Karl Schultz wrote:
> On Wed, 08 Feb 2006 22:26:27 -0800, raval.chintan wrote:
>
>> Dear Karl,
>>
>> Thanks for your tip. I was able to create the dlm successfully and the
>> calls to glDrawBuffer(GL_BACK_RIGHT) were also happening but could not
>> see the stereo rendering then I found that the stereo mode was not
>> getting switched on and a call to
>>
>> sprintf(szMessage,
>> "Current OpenGL Driver:\n%s\n%s\n%s\n ",
>> glGetString(GL_VENDOR),
>> glGetString(GL_RENDERER),
>> glGetString(GL_VERSION),
>> )
>> glGetBooleanv(GL_STEREO, &bStereo)
>>
>> returned null values for vendor, renderer and version and returned
>> GL_FALSE for GL_STEREO flag.
>
> Getting null values here is bad. Are you making the glGetString calls
> while an IDLgrWindow Draw is in progress? In other words, are you calling
> this from a Draw method that you have overridden in a subclass?
>
> Null values indicate that a GL context is not current and you are making
> these calls "out of band". You can't just make these calls from any point
> in your IDL program. They must be made while a draw in is progress.
>
>> Now my question is (sorry for asking too many questions but I hear the
>> folks here are tolerant and are kind ) how do I turn the stereo mode
>> programmatically ?
>
> This I do not know at the moment. How do you do it in a stand-alone GL
> application (outside of IDL)?? I'd have to research this, but maybe I'll
> leave it to you. :-) Of course, I'll figure it out when/if we add this to
> IDL. :-)
>
> In any case, you need to address the above context problem first.
>
>> if we use Pixelformatdescriptor than we need an handle to the window or
>> the context how can I get handle to IDL's window in dlm or is it that I
>> am completely going on wrong track here???
>
> Well, if this ends up needing to use a different PFD, then we are sunk.
> IDL does that deep inside and you cannot influence PFD selection.
> Further, you cannot change the PFD on a window once it is made current.
> I notice that there is a PFD_STEREO flag, but the Microsoft docs say this
> isn't supported. It may be that some ICD's support or pay attention to
> it. I know IDL does NOT set this flag when selecting a PFD, so if a PFD
> with PFD_STEREO set is required to activate stereo for your card, it isn't
> going to happen until RSI formally supports stereo.
>
>> Desperatly *seeking* answers
>
> Well, I never said that this would work out, and we gave it a try. IDL
> 6.2 and 6.3 simply does not support stereo and we're just trying to hack
> around it, and it doesn't look good now. But maybe you might still get
> someplace. If stereo support is really important to you, let RSI know
> about it.
>
> Karl
>
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47410 is a reply to message #47263] |
Thu, 09 February 2006 08:05 |
Karl Schultz
Messages: 341
Registered: October 1999
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Senior Member |
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On Wed, 08 Feb 2006 22:26:27 -0800, raval.chintan wrote:
> Dear Karl,
>
> Thanks for your tip. I was able to create the dlm successfully and the
> calls to glDrawBuffer(GL_BACK_RIGHT) were also happening but could not
> see the stereo rendering then I found that the stereo mode was not
> getting switched on and a call to
>
> sprintf(szMessage,
> "Current OpenGL Driver:\n%s\n%s\n%s\n ",
> glGetString(GL_VENDOR),
> glGetString(GL_RENDERER),
> glGetString(GL_VERSION),
> )
> glGetBooleanv(GL_STEREO, &bStereo)
>
> returned null values for vendor, renderer and version and returned
> GL_FALSE for GL_STEREO flag.
Getting null values here is bad. Are you making the glGetString calls
while an IDLgrWindow Draw is in progress? In other words, are you calling
this from a Draw method that you have overridden in a subclass?
Null values indicate that a GL context is not current and you are making
these calls "out of band". You can't just make these calls from any point
in your IDL program. They must be made while a draw in is progress.
>
> Now my question is (sorry for asking too many questions but I hear the
> folks here are tolerant and are kind ) how do I turn the stereo mode
> programmatically ?
This I do not know at the moment. How do you do it in a stand-alone GL
application (outside of IDL)?? I'd have to research this, but maybe I'll
leave it to you. :-) Of course, I'll figure it out when/if we add this to
IDL. :-)
In any case, you need to address the above context problem first.
>
> if we use Pixelformatdescriptor than we need an handle to the window or
> the context how can I get handle to IDL's window in dlm or is it that I
> am completely going on wrong track here???
Well, if this ends up needing to use a different PFD, then we are sunk.
IDL does that deep inside and you cannot influence PFD selection.
Further, you cannot change the PFD on a window once it is made current.
I notice that there is a PFD_STEREO flag, but the Microsoft docs say this
isn't supported. It may be that some ICD's support or pay attention to
it. I know IDL does NOT set this flag when selecting a PFD, so if a PFD
with PFD_STEREO set is required to activate stereo for your card, it isn't
going to happen until RSI formally supports stereo.
>
> Desperatly *seeking* answers
Well, I never said that this would work out, and we gave it a try. IDL
6.2 and 6.3 simply does not support stereo and we're just trying to hack
around it, and it doesn't look good now. But maybe you might still get
someplace. If stereo support is really important to you, let RSI know
about it.
Karl
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| Re: NVidia Quadro4 980 XGL card + IDL [message #47519 is a reply to message #47403] |
Tue, 14 February 2006 03:50 |
raval.chintan
Messages: 54
Registered: May 2005
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Member |
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Rick,Karl, Dick
Thank you very much for your *valuable* support.
I have find out a temporary solution. In this solution i am using JAVA,
JAI and JAVA3D and *of course* IDL.
I have used IDL java bridge for this application. In my application i
am rendering stereo on Java's window. For rendering I am passing my
data from IDL.
And of course this a temporary solution. It will be very nice if RSI
can provide this facility in IDL's future version.
As Rick has said that Journey is more *enjoyable* rather than
destination which is actually true.
Rick - If you can provide me a code and circuit diagram , then it would
be very helpful. Awaiting for your reply.
-Chintan
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