From: Brian Furtaw (brian++at++sgi.com)
Date: 10/30/2003 04:40:08
Try this create two pfChannels attach the rear view mirror channel to
your pfPipeWindow first then your out-the-window(OTW) channel second.
This will cause Performer to render them in the order you attached them.
In the Channel DRAW callback for the rearview mirror,
(pfChannel::setTravFuncs(PFTRAV_DRAW,...) ) call glCopyTexSubImage2D ()
to move the pixels from the rearview channel to a texture that will be
applied when the OTW channel is rendered.
Rearview channel draw callback...
RearChanDraw() {
chan->clear();
// pre -Draw stuff
pfDraw();
// copy pixels to texture
glCopyTexSubImage2D (...);
}
Brian
Volodymyr Kindratenko wrote:
> Chris:
>
> Thanks for the explanation, it helps.
>
> Well, I came up with a different solution. I render the mirror image in a
> separate pfPipeWindow and copy it from the screen buffer to the texture's
> image memory via glReadPixels. This is done in the pfPipeWindow's channel
> draw callback. This works as long as pfPipeWindow is visible on the screen.
> Setting pfPipeWindow type to PFPWIN_TYPE_PBUFFER results in not calling the
> pfPipeWindow's channel draw callback, so, no texture is rendered. How can I
> render to an off-screen buffer?
>
> Volodymyr
>
>
>>-----Original Message-----
>>From: Dorosky, Christopher G [mailto:christopher.g.dorosky++at++lmco.com]
>>Sent: Wednesday, October 29, 2003 4:27 PM
>>To: Volodymyr Kindratenko; Dick Rous
>>Cc: info-performer++at++sgi.com
>>Subject: RE: [info-performer] Subload pfTexture across multiple pipes
>>
>>
>>You have to subload them on each pipe.
>>No way around it, unless you want to take the frame hit and
>>have Performer call the tex->load() implicitly.
>>
>>Pipe 0 CANNOT share it's texture memory with Pipe 1.
>>Channel 0 CAN (and does) share it's texture memory with
>>channel 1, IF Channel 0&1 are on the same pipe.
>>
>>That saying was misleading. pfTexture's can have different
>>images in different pipes. Both must be directly subloaded,
>>even if they are the same.
>>
>>Think of the texture beign texture for a tank. One pipe could
>>be visual, the other IR. Possibly the same pfTexture, but
>>different image data.
>>
>>Chris
>>
>>-----Original Message-----
>>From: owner-info-performer++at++performer.engr.sgi.com
>>[mailto:owner-info-performer++at++performer.engr.sgi.com]On Behalf
>>Of Volodymyr Kindratenko
>>Sent: Wednesday, October 29, 2003 10:20 AM
>>To: 'Dick Rous'
>>Cc: info-performer++at++sgi.com
>>Subject: RE: [info-performer] Subload pfTexture across multiple pipes
>>
>>
>>Dick:
>>
>>Actually, it does not, and why should it be? Ideally I want
>>the texture image to be rendered only once on a separate pipe
>>and then be distributed to the remaining pipes (4-IR SGI
>>connected to a 3-wall CAVE). At the moment, the texture
>>rendering channel is attached to one of the 3 pipes used to
>>render the CAVE imagery. And sure enough, this pipe has the
>>right texture. How can I grab this texture and distribute it
>>to the remaining channels?
>>
>>Chapter 9. Graphics State from the OpenGL Performer Programmer's Guide
>>says:
>>"... pfSubloadTex() and pfSubloadTexLevel() can also be used
>>in the drawing process to do an immediate load of texture
>>memory managed by the given pfTexture and these routines
>>allow you to specify all loading parameters (source, origin,
>>size, etc.). THIS IS USEFUL FOR LOADING DIFFERENT IMAGES FOR
>>THE SAME pfTexture IN DIFFERENT GRAPHICS PIPELINES. ..." And
>>I need just the opposite, loading the same image in different
>>graphics pipelines.
>>
>>Volodymyr
>>
>>
>>>-----Original Message-----
>>>From: Dick Rous [mailto:dick++at++sgi.com]
>>>Sent: Wednesday, October 29, 2003 4:48 AM
>>>To: 'Volodymyr Kindratenko'; info-performer++at++sgi.com
>>>Subject: RE: [info-performer] Subload pfTexture across
>>
>>multiple pipes
>>
>>>
>>>Have you checked if the subload code in the draw callback is
>>>executed for each pipe?
>>>
>>>- Dick.
>>>
>>>
>>>>-----Original Message-----
>>>>From: Volodymyr Kindratenko [mailto:kindr++at++ncsa.uiuc.edu]
>>>>Sent: Wednesday, 29 October, 2003 01:08
>>>>To: info-performer++at++sgi.com
>>>>Subject: [info-performer] Subload pfTexture across multiple pipes
>>>>
>>>>
>>>>
>>>> Hello:
>>>>
>>>> I need to build a rear view mirror for a driver
>>>>simulator. To do
>>>>this, I define a separate channel for rendering rear view
>>>>mirror image and
>>>>in that channel's draw callback I subload the relevant
>>>>portion of the frame
>>>>buffer to the appropriate pfTexture. This works just fine on
>>>>a single pipe
>>>>system. How can I share this texture across multiple pipes
>>>>(CAVE)? In the
>>>>CAVE I see that the correct image is applied to a portion of
>>>>the mirror
>>>>polygon residing on the front wall (I use the front wall's
>>>>pipe rendering
>>>>the rear view channel), and nothing is applied to the portion
>>>>of the polygon
>>>>residing for example on the left wall. Basically, the
>>>>texture image is not
>>>>shared between the pipes. Please help!
>>>>
>>>> Volodymyr Kindratenko
>>>> NCSA, UIUC
>>>>
>>>>
>>>>--------------------------------------------------------------
>>>>---------
>>>> List Archives, Info, FAQ:
>>
>>http://www.sgi.com/software/performer/
>>
>>>> Open
>>
>>Development Project: http://oss.sgi.com/projects/performer/
>>
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>>>>
>>>
>>
>>--------------------------------------------------------------
>>---------
>> List Archives, Info, FAQ: http://www.sgi.com/software/performer/
>> Open Development Project: http://oss.sgi.com/projects/performer/
>> Submissions: info-performer++at++sgi.com
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>>
>
>
>
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