Paul Martz wrote:
On 5/6/2011 4:05 AM, Fred Smith wrote:
You usually want to create GL batches that are as large as possible. 10
draw calls of 100 elements will be slower than 1 draw call of 1000 elements.
Something else I have noticed a little while ago was that the stateset
On 5/9/2011 5:49 AM, Fred Smith wrote:
OSG is a great piece of code, don't get me wrong - but I see a weakness here.
What, exactly, does that mean?
--
Chris 'Xenon' Hanson, omo sanza lettere. xe...@alphapixel.com
http://www.alphapixel.com/
Digital Imaging. OpenGL. Scene Graphs. GIS. GPS.
It means that there seems to be a cost in doing state changes with OSG. GL
state changes do not necessarily incur any cost - this is implementation
specific anyway - whereas OSG state changes seem to always incur one, as even
going through empty statesets does incur a cost.
Is that clear
Hi Fred,
On Mon, May 9, 2011 at 3:42 PM, Fred Smith osgfo...@tevs.eu wrote:
It means that there seems to be a cost in doing state changes with OSG.
Indeed there is!! It's written to be lightweight, using pointer rater
than content comparisons where possible, but you can't ever disappear
CPU
Hi Robert,
The stateset performance issue, if ever encountered, can easily be worked
around with a draw callback using applyAttribute/applyTextureAttribute prior to
rendering every drawable.
This is a very slim point where there might be room for improvement, and what
you said perfectly makes
Hi All,
Paul, I think I've done some of the benchmark you're referring to on my end
right before starting this thread =)
In my example I replicate the same geometric primitive many times.
The geometric object is a little cube counting 40 vertex and 66 triangles
all rendered as a single
Hi Ricky,
Given you have 20,000 instances their will and cull and draw dispatch
bottleneck. Sharing VBO's won't really share this much. The big
elephant in the room is the number of seperate objects to traverse in
the cull and draw traversals and the number of seperate GL calls that
will have
Hi Robert,
thank you for your advice, but I used 20.000 only for benchmarking purposes,
I'll balance better the scenegraph in the real application.
Even so, with the scenario number 2, I was hoping to achieve performances
closer to scenario 3 than 1,
as the stats scale quite in linear way with
You usually want to create GL batches that are as large as possible. 10 draw
calls of 100 elements will be slower than 1 draw call of 1000 elements.
Something else I have noticed a little while ago was that the stateset
processing engine of OSG might be slow. One thing I have been surprised with
Hi Ricccardo,
On Fri, May 6, 2011 at 10:53 AM, Riccardo Corsi
riccardo.co...@kairos3d.it wrote:
Do you think the approach you suggest, avoiding explicit buffer unbind,
would provide some benefit?
It's unlikely to make a big difference as it's only one small part of
all the operations being
On 5/6/2011 4:05 AM, Fred Smith wrote:
You usually want to create GL batches that are as large as possible. 10 draw
calls of 100 elements will be slower than 1 draw call of 1000 elements.
Something else I have noticed a little while ago was that the stateset
processing engine of OSG might be
www.reallyslick.com
Message: 3
Date: Sun, 2 Jan 2011 21:28:12 -0500
From: Jason Beverage jasonbever...@gmail.com
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb
-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb-vewdrpkp0rwjxcok2jm4o0vdx31ao...@mail.gmail.com
Content-Type: text/plain; charset=ISO-8859-1
Hi Terry,
You can pack the verts of your small objects into a single
osg::Vec3Array and share that array across multiple
...@gmail.com
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb-vewdrpkp0rwjxcok2jm4o0vdx31ao...@mail.gmail.com
Content-Type: text/plain; charset=ISO-8859-1
Hi Terry,
You can pack
: Jason Beverage jasonbever...@gmail.com
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb-vewdrpkp0rwjxcok2jm4o0vdx31ao...@mail.gmail.com
Content-Type: text/plain; charset=ISO-8859-1
On 5/5/2011 9:51 AM, Glenn Waldron wrote:
AFAIK, OSG doesn't maintain VBO/EBO bindings as part of its sortable state. So I
believe they will be bound and unbound for each Geometry, even if they are
shared. Somebody correct me if I'm wrong. (See Geometry::drawImplementation.)
This is my
On Thu, May 5, 2011 at 12:59 PM, Paul Martz pma...@skew-matrix.com wrote:
On 5/5/2011 9:51 AM, Glenn Waldron wrote:
AFAIK, OSG doesn't maintain VBO/EBO bindings as part of its sortable
state. So I
believe they will be bound and unbound for each Geometry, even if they are
shared. Somebody
On 5/5/2011 11:26 AM, Glenn Waldron wrote:
On Thu, May 5, 2011 at 12:59 PM, Paul Martz pma...@skew-matrix.com
mailto:pma...@skew-matrix.com wrote:
On 5/5/2011 9:51 AM, Glenn Waldron wrote:
AFAIK, OSG doesn't maintain VBO/EBO bindings as part of its sortable
state. So I
HI All,
Current the OSG does unbind VBO's at the end of
osg::Geometry::drawImplementation(..) so that VBO and EBO state
doesn't leak into adjoining Drawables. If an implementation is known
to only use VBO's, with no display lists then potentially we could not
bother with the unbind at the end
www.reallyslick.com
Message: 3
Date: Sun, 2 Jan 2011 21:28:12 -0500
From: Jason Beverage jasonbever...@gmail.com
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb-vewdrpkp0rwjxcok2jm4o0vdx31ao
jasonbever...@gmail.com
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
Subject: Re: [osg-users] large VBOs for multiple Drawables
Message-ID:
aanlktin2mdb-vewdrpkp0rwjxcok2jm4o0vdx31ao...@mail.gmail.com
Content-Type: text/plain; charset=ISO-8859-1
Hi Terry,
You can pack
Hi Terry,
You can pack the verts of your small objects into a single
osg::Vec3Array and share that array across multiple osg::Geometry
objects then use DrawElements for each geometry with the correct
indices. I've just recently done this actually for a project I'm
working on and it's worked out
I found some email threads that hinted at this a little, but nothing
seemed very specific. I have scenes where display lists perform a bit
better than VBOs. My best guess is because my objects have relatively
small vertex counts (usually between 20 and 200). Is there any way in
OSG to use one
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