Hi Dennis,

This stuff really is driver/hardware related rather than OSG related.
I'm afraid I can't help you, even if I had time to.

Robert.

On 2/26/07, Bunfield, Dennis AMRDEC/Davidson
<[EMAIL PROTECTED]> wrote:
Hi Robert,
I can't imagine I would be blowing texture memory when I have 1GB of
texture memory available to me on the Quadro card.

Here's a matrix of my test results as well as plots of the results are
attached (I used texture rectangle with the GL_FLOAT_RGBA32_NV texture
format which I found gives best performance)

For POT textures, degradation is odd for >= 128x128 sizes. (see
POTHDR.png)
TexSize 4FBOs   8FBOs   9FBOs
1024x1024       400Hz   300Hz   1Hz
512x512 800Hz   600Hz   20Hz
256x256 900Hz   700Hz   70Hz
128x128 900Hz   700Hz   240Hz
64x64           240Hz   170Hz   150Hz
32x32           380Hz   260Hz   230Hz
16x16           410Hz   300Hz   270Hz
8x8             410Hz   325Hz   270Hz

For NPOT textures the performance degrades in a reasonable fashion. (see
NPOTHDR.png)
NPOT Texure     4FBOs   8FBOs   9FBOs   16FBOs
640x640 265Hz   180Hz   105Hz   50Hz
500x500 395Hz   280Hz   150Hz   80Hz
320x320 670Hz   490Hz   300Hz   165Hz
300x300 720Hz   530Hz   320Hz   185Hz
210x210 950Hz   720Hz   480Hz   285Hz
105x105 950Hz   720Hz   520Hz   360Hz
75x75           940Hz   710Hz   520Hz   360Hz
50x50           940Hz   710Hz   520Hz   360Hz
10x10           940Hz   710Hz   520Hz   360Hz


Based on these results do you think something weird is happening with >
8 FBO's for POT textures?  Can there be something going on with the way
the CameraNode sets up the RTT or it would it more likely be a driver
issue? Or is it simply a way the graphics card optimizes textures?

I might need to redesign what I'm trying to accomplish and use less
FBO's.  I know I have 8 attachment points to for each fbo, but is it
feasible to toggle the geometry using a switch node for each attachment
point in a cameranode postdrawcallback after each rtt draw?

Thanks a lot,
Dennis

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Robert
Osfield
Sent: Monday, February 26, 2007 10:11 AM
To: osg users
Subject: Re: [osg-users] Performance drops when using 4 or more camera
nodes(RTT)

Hi Dennis,

I'm afraid I don't have time to do performance testing on behalf of
users.

What might be causing the problem?  GPU Memory? Maybe.  Try reducing FBO
sizes.

Robert.

On 2/26/07, Bunfield, Dennis AMRDEC/Davidson
<[EMAIL PROTECTED]> wrote:
> Hi Robert,
>
> I'm also having a problem with the massive performance drop with
> multiple (in my case > 8) HDR RTT camera nodes .  I am using a Quadro
> FX 5500 G with 1 GB of memory, so I know it isn't my graphics card
> memory (the same problem happens on my GeForce Go 7800).  I'm also
> running under Linux with 2 dual core opeterons.  My RTT sizes are
> 512x512 with nearest/nearest mipmapping and I'm using 32 bit HDR
rendering.
>
> I have made some simple modifications to osgprerender.cpp (see
> attached) to illustrate the problem I and others appear to have seen.

> I also hard coded the values I'm using in osgprerender and set up the
proper 512x512
> HDR settings for both texture 2D's and texture rectangles.   8 RTT
> camera nodes run great with a small performance drop for each camera
> as would be expected.  When I add the 9th camera node that is when
> things break.  All that you need to do to run it is pass in a model
> and if you want texture rectangle use --texture-rectangle.
>
> Is this there a frame buffer object limitation of the driver/card?  I
> thought the number of FBO's was only limited by the amount of texture
> memory available on the card, but I'm using a card with 1GB of memory
> and not overly large textures.
>
> Thanks,
> Dennis
>
> >> From: Robert Osfield <robert.osfield_at_gmail.com>
> >> Date: Tue Jan 23 2007 - 00:50:39 PST
> >>
> >> Hi Brian,
> >>
> >> I'd check to see if you graphics card has sufficient memory for
> >> what you are trying to do
> >>
> >> Robert.
> >>
> >> On 22 Jan 2007 23:27:35 -0000, [EMAIL PROTECTED]
> <[EMAIL PROTECTED]> wrote:
> >>> Hi,
> >>>
> >>> I'm using floating point textures as my targets for multipass RTT.
> In my
> >>> tests I have noticed that if three or less camera nodes are set up
> using
> >>> GL_RGBA16F_ARB internal format textures, the frame rate stays at a
> constant
> >>> 75FPS when only the texture is rendered to the screen (i.e. the
> texture is
> >>> rendered over the full window).
> >>>
> >>> If I add an additional camera node, the frame rate drops to 15
FPS.
> Five
> >>> nodes yields 8FPS, and 5FPS are achieved with six nodes. Also, if
> >>> I
> set
> >>> the texture to render to 1/4 of the screen and position the main
> camera so
> >>> that the actual scene being rendered to texture is visible, I'll
> >>> get
> 25FPS
> >>> for the three camera node implementation.
> >>>
> >>> I'm setting up my textures with internal formats of
> >>> GL_RGBA16F_ARB,
> a
> >>> source type of GL_FLOAT, and a source format of GL_RGBA.
> >>>
> >>> The FBO is set up like:
> >>> fbo->setAttachment(GL_COLOR_ATTACHMENT0_EXT,
> >>> osg::FrameBufferAttachment(texture));
> >>>
> >>> fbo->setAttachment(GL_DEPTH_ATTACHMENT_EXT,
> >>> osg::FrameBufferAttachment(new osg::RenderBuffer(512, 512,
> >>> GL_DEPTH_COMPONENT24)));
> >>>
> >>> My min/max filters are set up as NEAREST.
> >>>
> >>> If I change my textures to internal formats of GL_RGBA and the
> source type
> >>> as GL_UNSIGNED_BYTE, my performance is great.
> >>>
> >>> Any thoughts?
> >>>
> >>> Thanks,
> >>> Brian
> >>> _______________________________________________
> >>> osg-users mailing list
> >>> [email protected]
> >>> http://openscenegraph.net/mailman/listinfo/osg-users
> >>> http://www.openscenegraph.org/
> >>>
> >
>
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>
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