Re: [Opensg-users] [OpenSG 2.0] Rendering multiple times into an FBO without SimpleSceneManager

[Constantin M. <con...@go...>]

Hi,


>> > I have some problem attaching the patches.
>> > I used the SVN repository-sources of OpenSG.
>> >
>> > I have never worked with patches before so I tried to apply the last patch.
>> > This did not work with svn (now I know it's because the patch is from git).
>> > Therefore I had to apply the patch by hand.
>> > This worked quite ok, but I'm very interested in how to apply it properly.
>> > Today I tried to apply the 2nd patch. Therefore I installed Git and
>> > cloned the http://www.cgmt.org/user/gerrit/OpenSG.git repo.
>>

I could apply the patch to the SVN repository and the github repository as well.
Thanks for your instructions.
I now just added the second patch, because otherwise it could not
apply the second patch.
Is this right, or did I make a mistake and lost some changes?

>> I'm not sure if Gerrit keeps that one up to date,
>
> not really, that one might be really old and will go offline anytime.
>
>> please use the repos
>> hosted at github:
>>
>> http://github.com/vossg/OpenSGDevMaster
>>
>> If you got the above one from the wiki I'd appreciate it if you could
>> let us know which page we need to update, thanks!
>
> I had the old one on the developer page at one point in time, but I
> changed it as I moved things to github.

I found the other git repository on the mailing list, so I don't think
you have to change the adress on the website.


The patch does not work for me.
My program crashs, because the image is still not valid, but a
glReadPixels is executed to write to the Image, this results in a
writing access violation.

Here is the glTrace to the point, where the program crashs.

|  ...
|  glCallList(1)
|  glGetError()
|  glActiveTextureARB(GL_TEXTURE0)
|  glDisable(GL_TEXTURE_2D)
|  glGetError()
|  glColorMask(TRUE, TRUE, TRUE, TRUE)
|  glDepthFunc(GL_LEQUAL)
|  glDepthMask(TRUE)
|  glDisable(GL_LIGHTING)
|  glDisable(GL_COLOR_MATERIAL)
|  glDepthMask(FALSE)
|  glDepthMask(TRUE)
|  glMatrixMode(GL_PROJECTION)
|  glPopMatrix()
|  glMatrixMode(GL_MODELVIEW)
|  glPopAttrib()
|  glReadBuffer(GL_COLOR_ATTACHMENT0_EXT)
|  glReadPixels(0, 0, 64, 64, GL_RGBA, GL_UNSIGNED_BYTE, 074B0888)
|  glReadBuffer(GL_POINTS)
|  glGetError()
|  glReadBuffer(GL_POINTS)
|  glReadPixels(0, 0, 64, 64, GL_DEPTH_STENCIL_NV,
GL_UNSIGNED_INT_24_8_NV, 00000000)
E! Child process exited
W! Program termination forced!

This is caused by the glReadPixels in the
TextureBuffer::processPreDeactivate(DrawEnv *pEnv, UInt32 index)
function.

Thanks for your efforts,
Constantin