Re: [osg-users] update of zNear and zFar during drawing
On Fri, Apr 24, 2009 at 2:42 PM, Gianluca Natale wrote: > Robert, > is there a quick way to simply update near and far clipping planes for > perspective > projection, without calling an explicitly redraw (I mean, some visitor that > computes for example the bounding box of the model and updates near and far > clipping plane also)? There is no quick way, you'll need to do this by hand. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] update of zNear and zFar during drawing
Robert, is there a quick way to simply update near and far clipping planes for perspective projection, without calling an explicitly redraw (I mean, some visitor that computes for example the bounding box of the model and updates near and far clipping plane also)? Thanks, Gianluca -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Gianluca Natale Sent: venerdì 24 aprile 2009 12.29 To: 'OpenSceneGraph Users' Subject: Re: [osg-users] update of zNear and zFar during drawing Thank you again, Robert. -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: venerdì 24 aprile 2009 11.54 To: OpenSceneGraph Users Subject: Re: [osg-users] update of zNear and zFar during drawing On Fri, Apr 24, 2009 at 10:39 AM, Gianluca Natale wrote: > Thank you Robert, > I apologize for my ignorance. > Actually I don't want to make any zoom in, I just want to > clip objects behind the camera (is there any problem in > clipping a sphere against a rectangular box?) You can do what you want with the near + far clipping planes in orthographic and perspetive projections simply by switch off the automatic compute of the near and planes via camera->setComputeNearFar(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR); But this won't make othrographic magically appropriate for doing internal views. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.12.4/2077 - Release Date: 04/23/09 19:21:00 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.12.4/2077 - Release Date: 04/23/09 19:21:00 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] update of zNear and zFar during drawing
Thank you again, Robert. -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: venerdì 24 aprile 2009 11.54 To: OpenSceneGraph Users Subject: Re: [osg-users] update of zNear and zFar during drawing On Fri, Apr 24, 2009 at 10:39 AM, Gianluca Natale wrote: > Thank you Robert, > I apologize for my ignorance. > Actually I don't want to make any zoom in, I just want to > clip objects behind the camera (is there any problem in > clipping a sphere against a rectangular box?) You can do what you want with the near + far clipping planes in orthographic and perspetive projections simply by switch off the automatic compute of the near and planes via camera->setComputeNearFar(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR); But this won't make othrographic magically appropriate for doing internal views. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.12.4/2077 - Release Date: 04/23/09 19:21:00 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] update of zNear and zFar during drawing
On Fri, Apr 24, 2009 at 10:39 AM, Gianluca Natale wrote: > Thank you Robert, > I apologize for my ignorance. > Actually I don't want to make any zoom in, I just want to > clip objects behind the camera (is there any problem in > clipping a sphere against a rectangular box?) You can do what you want with the near + far clipping planes in orthographic and perspetive projections simply by switch off the automatic compute of the near and planes via camera->setComputeNearFar(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR); But this won't make othrographic magically appropriate for doing internal views. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] update of zNear and zFar during drawing
Thank you Robert, I apologize for my ignorance. Actually I don't want to make any zoom in, I just want to clip objects behind the camera (is there any problem in clipping a sphere against a rectangular box?) Thanks, Gianluca -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: venerdì 24 aprile 2009 11.02 To: OpenSceneGraph Users Subject: Re: [osg-users] update of zNear and zFar during drawing HI Gianluca, Arggghhg... You can't use orthographic projects in the same way that you use perspective projections, it simply doesn't work. Use orthographic projections for external views of the scene where clipping is not used. Do *not* use it for internal views where clipping is critical. Try to do this on and you'll just waste lots of your time and lots of the communities time trying to explain to you why it won't work. Robert. On Fri, Apr 24, 2009 at 9:44 AM, Gianluca Natale wrote: > Hi all. > I have a strange behavior when I let OSG update the near and far clipping > planes during drawing. > When I use a perspective projection, and I move the camera inside the model > (I mean, inside the global > > bounding sphere of the model), the near clipping plane is placed very near > to the camera, so to clip > > as few objects as possible. I like this behavior, and I would like to use it > also for Orthogonal projections. > But in that case, when I move the camera into the model, the near clipping > plane becomes negative, > so the viewing volume includes always the whole model. And I dont like this > now. > > Is this the right behavior, or did I miss something/make some mistake? > If this is the way it works for orthogonal projections, is there a way to > make it work like perspective one? > > > > Thanks in advance. > > Gianluca Natale > > > > ___ > 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.12.4/2077 - Release Date: 04/23/09 19:21:00 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] update of zNear and zFar during drawing
HI Gianluca, Arggghhg... You can't use orthographic projects in the same way that you use perspective projections, it simply doesn't work. Use orthographic projections for external views of the scene where clipping is not used. Do *not* use it for internal views where clipping is critical. Try to do this on and you'll just waste lots of your time and lots of the communities time trying to explain to you why it won't work. Robert. On Fri, Apr 24, 2009 at 9:44 AM, Gianluca Natale wrote: > Hi all. > I have a strange behavior when I let OSG update the near and far clipping > planes during drawing. > When I use a perspective projection, and I move the camera inside the model > (I mean, inside the global > > bounding sphere of the model), the near clipping plane is placed very near > to the camera, so to clip > > as few objects as possible. I like this behavior, and I would like to use it > also for Orthogonal projections. > But in that case, when I move the camera into the model, the near clipping > plane becomes negative, > so the viewing volume includes always the whole model. And I don’t like this > now. > > Is this the right behavior, or did I miss something/make some mistake? > If this is the way it works for orthogonal projections, is there a way to > make it work like perspective one? > > > > Thanks in advance. > > Gianluca Natale > > > > ___ > 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] update of zNear and zFar during drawing
Hi all. I have a strange behavior when I let OSG update the near and far clipping planes during drawing. When I use a perspective projection, and I move the camera inside the model (I mean, inside the global bounding sphere of the model), the near clipping plane is placed very near to the camera, so to clip as few objects as possible. I like this behavior, and I would like to use it also for Orthogonal projections. But in that case, when I move the camera into the model, the near clipping plane becomes negative, so the viewing volume includes always the whole model. And I don't like this now. Is this the right behavior, or did I miss something/make some mistake? If this is the way it works for orthogonal projections, is there a way to make it work like perspective one? Thanks in advance. Gianluca Natale ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
