Re: [osg-users] Techniques to shift CPU load to GPU

[David Heitbrink]

This is a pretty broad topic. It largely depends on what you are trying to 
display. 

If you are displaying a lot of the same thing, (say a warehouse filled with 
1000's of identical boxes) you can use hardware instancing, there are a of 
sources you can look up on the subject. The OSG forest example is pretty good. 
This is a pretty good link:

http://3dcgtutorials.blogspot.com/2013/08/instancing-with-openscenegraph.html

 The osg GPU Cull example is a bit more complicated example, but pretty good, 
but this also depends on displaying a lot of the same thing. 

You can look at tessellation and geometry shaders and what can be done with 
those.  

Other things you may look at are simpler like combining geometries. If you have 
1000's of objects with with a handful of triangles each, combining them into a 
single primitive set can help a lot. You may need to use a texture atlas to get 
this done. 

Simply drawling less stuff, by using occlusion nodes can help a lot.  

These may or may not be applicable for you depending on your scene. Whats in 
your scene-graph? How is it being updated every frame. Is it a static scene, 
are you manipulating a lot meshes every frame? 

Overall this is really broad, and some of it can get complicated fast. Without 
knowing what you are trying to do it is really hard to give any meaningful 
advice.

--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=67148#67148





___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Re: [osg-users] Pixel size

[Clement.Chu]

Hi Robert,

  Thanks for your help.  I found I can do it on osgVolume:Locator 
setTransformAsExtents method.  Thanks.


Regards,
Clement Chu


From: osg-users  on behalf of 
Robert Osfield 
Sent: Friday, 13 May 2016 19:28
To: OpenSceneGraph Users
Subject: Re: [osg-users] Pixel size

Hi Clement,

The osgVolume::Locator that you assign to the ImageLayer and
VolumeTile positioning the unit cube of the texture into object space.

Robert.

On 12 May 2016 at 08:23,   wrote:
> Hi,
>
>
>   I have a question about pixel size in volume rendering.  Is current pixel
> size 1 x 1 x 1? If the pixel is changed to 1.2 x 1.5 x 1.6, where can I set
> this information on osgVolume?  Thanks.
>
>
>
> Regards,
> Clement
>
>
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Re: [osg-users] Up vectors in setHomePosition with FirstPersonManipulator doesn't seems to affect camera view changes

[Simone Rapposelli]

Hi Robert,

first of all thank you for your reply.
I am already able to set the correct position by using sethomeposition and then 
calling home, but my problem is that I need to set a specific "up" vector: I 
have tried any possible setting but my camera rest always in the default 
(0,0,1) orientation (I didn't specify that I need to show a point cloud in 
perspective view from the ground).
By using for example TrackBallManipulator instead it works, so it seems that is 
a problem of this manipulator that doesn't allow to set up vector.
Is there a manipulator similar to FirstPersonManipulator that allow to set the 
"up" vector?
Thank you again

--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=67140#67140





___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Re: [osg-users] Techniques to shift CPU load to GPU

[Robert Osfield]

Hi Rajani,

There isn't much we can help you with without you specifying a lot
more about the particulars of your scene graph, what you goals are.
The problem is so open ended, there are so many different ways to
optimize software and scene graphs that you can't give an answer to
open ended questions like yours, you are essential asking us to
teaching something that would take a chunk of time to teach in a
training course.

Robert.

On 28 April 2016 at 07:38, Rajani Godson  wrote:
> Hi,
> Iam using OSG Engine as the rendering tool for my application currently iam 
> facing frame delay because my CPU load is 100% but my GPU is taking only 20 
> to 40 % usage.How to
>  shift CPU load to GPU.
> Graphics Card:-Nvidia Quadro 6000
> Operating System:Ubuntu 12.4LTS
>
> Thank you!
>
> Cheers,
> Rajani
>
> --
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=66992#66992
>
>
>
>
>
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Re: [osg-users] Up vectors in setHomePosition with FirstPersonManipulator doesn't seems to affect camera view changes

[Robert Osfield]

Hi Simone,

The setHomePosition() sets the home position, it doesn't affect the
current position of camera manipulator.  If you call home() on the
camera manipulator or press the home key then it'll jump to this
position if the camera manipulator supports home.

Robert.

On 17 May 2016 at 19:28, Simone Rapposelli  wrote:
> Hi,
>
> I am newbie, so please excuse me for my possible blunders...
>
> I am trying to set eye, center and up vector in setHomePosition of a 
> FirstPersonManipulator.
> It works correctly but if I set whatever components in the "up" vector, 
> anything change in the viewer (I would like to have such a roll behavior).
> What am I doing wrong?
>
> Thank you!
>
> Cheers,
> Simone :'
>
> --
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=67133#67133
>
>
>
>
>
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org