[osg-users] Slow down with shared nodes

[Andre Normann]

Hi Robert,

when I use display lists instead of vertex buffer objects
(using osgUtil::GLObjectsVisitor), everything is fine with 3.4.0.

André


2017-03-08 8:40 GMT+01:00 Andre Normann <andre.normann at gmail.com>:

> Hi Robert,
>
> attached you will find two screenshots while running in
> SingleThreaded-Mode. Using osgUtil::Optimizer does not make any big
> difference. I will try to create an example, so that you can test it on
> your computer.
>
> André
>
>
> 2017-03-07 18:10 GMT+01:00 Robert Osfield <robert.osfield at gmail.com>:
>
>> Hi André,
>>
>> Thanks for the screenshots.  They tells us it's the draw dispatch that
>> is gating performance, so the question now moves to why draw dispatch
>> is so slow in this case.
>>
>> Are you running the osgUtil::Optimizer on your scene graph?
>>
>> Could you run the tests with SingleThreaded threading model?
>>
>> There may be chance that a bug fix to the OSG somewhere has tightened
>> up the assumptions it makes about threading.  That's just a guess
>> though, there still is too few titbits of information to know what the
>> cause is.
>>
>> Robert.
>>
>>
>>
>> On 7 March 2017 at 16:40, Andre Normann <andre.normann at gmail.com> wrote:
>> > Hi Robert,
>> >
>> > some more screenshots. This time without any other model.
>> >
>> > 3.2.3_1: My application using 3.2.3 and sharing nodes
>> > 3.4.0_1: My application using 3.4.0 and sharing nodes
>> > 3.4.0_2: My application using 3.4.0 without sharing nodes
>> >
>> > Best regards,
>> > André
>> >
>> >
>> > 2017-03-07 17:27 GMT+01:00 Andre Normann <andre.normann at gmail.com>:
>> >>
>> >> Hi Robert,
>> >>
>> >> I attached two screenshots. As you can see, I am doing nothing fancy
>> here.
>> >> There is a VirtualPlanetBuilder model present in the scene, but this
>> model
>> >> is hidden for my test case. The test scene contains only some thousand
>> >> triangles and I am using a GeForce 1080 which can handle much more.
>> >> Currently I have no idea what is going wrong here.
>> >>
>> >> -André
>> >>
>> >>
>> >> 2017-03-07 11:33 GMT+01:00 Robert Osfield <robert.osfield at gmail.com>:
>> >>>
>> >>> Hi André,
>> >>>
>> >>> I can't think of any changes between 3.2.x and 3.4.0 that would cause
>> >>> a slow down like you are describing.
>> >>>
>> >>> The best way to start looking at what might be the cause would be to
>> >>> isolate what part of the application is the bottleneck, the first step
>> >>> would be to use on the on screen stats and then look at the costs of
>> >>> the update, event, cull, draw dispatch and draw GPU phases.
>> >>>
>> >>> Also have a look at the full stats with to see if there is a different
>> >>> number of nodes or state being rendered in the two cases.
>> >>>
>> >>> Robert.
>> >>>
>> >>>
>> >>>
>> >>> On 7 March 2017 at 08:21, Andre Normann <andre.normann at gmail.com>
>> wrote:
>> >>> > Hi,
>> >>> >
>> >>> > I am currently migrating from OpenSceneGraph 3.2.3 to 3.4.0. In my
>> >>> > application I get a significant slow down, when I share nodes. Here
>> is
>> >>> > a
>> >>> > quick example layout of my scenegraph:
>> >>> >
>> >>> >
>> >>> > Parent
>> >>> >   |
>> >>> >   + ---> MatrixTransform1 --> Node1
>> >>> >   |
>> >>> >   + ---> MatrixTransform2 --> Node1
>> >>> >   |
>> >>> >   ...
>> >>> >   |
>> >>> >   + ---> MatrixTransform3 --> Node1
>> >>> >
>> >>> > I have a root node with several MatrixTransforms. The nodes below
>> the
>> >>> > MatrixTransforms are shared. In 3.2.3 everything works well and I
>> have
>> >>> > a
>> >>> > framerate of 60 Hz. In 3.4.0 the framerate drops with each new added
>> >>> > MatrixTransform. But when I do not share the nodes and instead
>> create
>> >>> > clones
>> >>> > with a DEEP_COPY_ALL flag, everything is well in 3.4.0.
>> >>> >
>> >>> > So what could cause the slow down in 3.4.0 with node sharing?
>> >>> >
>> >>> > I am using OpenSceneGraph 3.2.3/3.4.0 with a release build on
>> Window 7.
>> >>> >
>> >>> >
>> >>> > Best regards,
>> >>> > André
>> >>> >
>> >>> >
>> >>> > _______________________________________________
>> >>> > osg-users mailing list
>> >>> > osg-users at lists.openscenegraph.org
>> >>> >
>> >>> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-opens
>> cenegraph.org
>> >>> >
>> >>> _______________________________________________
>> >>> osg-users mailing list
>> >>> osg-users at lists.openscenegraph.org
>> >>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-opens
>> cenegraph.org
>> >>
>> >>
>> >
>> >
>> > _______________________________________________
>> > osg-users mailing list
>> > osg-users at lists.openscenegraph.org
>> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-opens
>> cenegraph.org
>> >
>> _______________________________________________
>> osg-users mailing list
>> osg-users at lists.openscenegraph.org
>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openscenegraph.org/pipermail/osg-users-openscenegraph.org/attachments/20170308/fad5a9ff/attachment-0003.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 3.4.0_with_Displaylists.jpg
Type: image/jpeg
Size: 66013 bytes
Desc: not available
URL: <http://lists.openscenegraph.org/pipermail/osg-users-openscenegraph.org/attachments/20170308/fad5a9ff/attachment-0003.jpg>