[osg-users] modify children in node callback?
In general, is it ok to modify child nodes in a node callback method? That is, children of the node for which the callback was called? I assume it must be. If not, how do you add or remove nodes of a scene graph while running? Cory ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] modify children in node callback?
Cory, You can't modify the hierarchy during an active traversal - this will mess up the traversal. You need to cache your updates and perform them between traversals. Brian This is a PRIVATE message. If you are not the intended recipient, please delete without copying and kindly advise us by e-mail of the mistake in delivery. NOTE: Regardless of content, this e-mail shall not operate to bind CSC to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose. • -osg-users-boun...@lists.openscenegraph.org wrote: - To: OpenSceneGraph Users osg-users@lists.openscenegraph.org From: Cory Riddell c...@codeware.com Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/02/2009 02:45PM Subject: [osg-users] modify children in node callback? In general, is it ok to modify child nodes in a node callback method? That is, children of the node for which the callback was called? I assume it must be. If not, how do you add or remove nodes of a scene graph while running? Cory ___ 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] modify children in node callback?
Thanks Brian, that makes sense. Is there a pre (or post) traversal callback that I can hook to make the changes, or must I manually mange the frame loop to make the changes? Cory Brian R Hill wrote: Cory, You can't modify the hierarchy during an active traversal - this will mess up the traversal. You need to cache your updates and perform them between traversals. Brian This is a PRIVATE message. If you are not the intended recipient, please delete without copying and kindly advise us by e-mail of the mistake in delivery. NOTE: Regardless of content, this e-mail shall not operate to bind CSC to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose. • -osg-users-boun...@lists.openscenegraph.org wrote: - To: OpenSceneGraph Users osg-users@lists.openscenegraph.org From: Cory Riddell c...@codeware.com Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/02/2009 02:45PM Subject: [osg-users] modify children in node callback? In general, is it ok to modify child nodes in a node callback method? That is, children of the node for which the callback was called? I assume it must be. If not, how do you add or remove nodes of a scene graph while running? Cory ___ 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] modify children in node callback?
I usually do it in the main loop, something like:
while(!viewer.done())
{
// do updates here
update_scene_graph(...);
viewer.frame();
}
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-osg-users-boun...@lists.openscenegraph.org wrote: -
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
From: Cory Riddell c...@codeware.com
Sent by: osg-users-boun...@lists.openscenegraph.org
Date: 03/02/2009 03:41PM
Subject: Re: [osg-users] modify children in node callback?
Thanks Brian, that makes sense.
Is there a pre (or post) traversal callback that I can hook to make the
changes, or must I manually mange the frame loop to make the changes?
Cory
Brian R Hill wrote:
Cory,
You can't modify the hierarchy during an active traversal - this will
mess
up the traversal. You need to cache your updates and perform them between
traversals.
Brian
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delete without copying and kindly advise us by e-mail of the mistake in
delivery.
NOTE: Regardless of content, this e-mail shall not operate to bind CSC to
any order or other contract unless pursuant to explicit written agreement
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purpose. •
-osg-users-boun...@lists.openscenegraph.org wrote: -
To: OpenSceneGraph Users osg-users@lists.openscenegraph.org
From: Cory Riddell c...@codeware.com
Sent by: osg-users-boun...@lists.openscenegraph.org
Date: 03/02/2009 02:45PM
Subject: [osg-users] modify children in node callback?
In general, is it ok to modify child nodes in a node callback method?
That is, children of the node for which the callback was called?
I assume it must be. If not, how do you add or remove nodes of a scene
graph while running?
Cory
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Re: [osg-users] modify children in node callback?
Brian R Hill wrote on Monday, March 02, 2009 2:29 PM: You can't modify the hierarchy during an active traversal - this will mess up the traversal. You need to cache your updates and perform them between traversals. Changes to the scenegraph should be made during the update traversal (so, inside an UpdateCallback), which is single-threaded so it is safe. The easiest way to prevent certain nodes from being traversed is to modify their node mask (the Camera also needs its traversal mask set so it will ignore these nodes). The main problem with removing/adding nodes is invalidating iterators, so I think it should be safe to add or remove children of the node currently being visited in the update pass; at the point of the UpdateCallback, I wouldn't expect any iterators to be iterating over that node's child list. -osg-users-boun...@lists.openscenegraph.org wrote: - To: OpenSceneGraph Users osg-users@lists.openscenegraph.org From: Cory Riddell c...@codeware.com Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/02/2009 02:45PM Subject: [osg-users] modify children in node callback? In general, is it ok to modify child nodes in a node callback method? That is, children of the node for which the callback was called? I assume it must be. If not, how do you add or remove nodes of a scene graph while running? Cory ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] modify children in node callback?
Bryan, Thanks for pointing that out. I've always just done it outside of all the traversals and never looked for other ways - probably has something to do with the old dog, no new tricks thing :) Brian -osg-users-boun...@lists.openscenegraph.org wrote: - To: OpenSceneGraph Users osg-users@lists.openscenegraph.org From: Thrall, Bryan bryan.thr...@flightsafety.com Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/02/2009 04:00PM Subject: Re: [osg-users] modify children in node callback? Brian R Hill wrote on Monday, March 02, 2009 2:29 PM: You can't modify the hierarchy during an active traversal - this will mess up the traversal. You need to cache your updates and perform them between traversals. Changes to the scenegraph should be made during the update traversal (so, inside an UpdateCallback), which is single-threaded so it is safe. The easiest way to prevent certain nodes from being traversed is to modify their node mask (the Camera also needs its traversal mask set so it will ignore these nodes). The main problem with removing/adding nodes is invalidating iterators, so I think it should be safe to add or remove children of the node currently being visited in the update pass; at the point of the UpdateCallback, I wouldn't expect any iterators to be iterating over that node's child list. -osg-users-boun...@lists.openscenegraph.org wrote: - To: OpenSceneGraph Users osg-users@lists.openscenegraph.org From: Cory Riddell c...@codeware.com Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/02/2009 02:45PM Subject: [osg-users] modify children in node callback? In general, is it ok to modify child nodes in a node callback method? That is, children of the node for which the callback was called? I assume it must be. If not, how do you add or remove nodes of a scene graph while running? Cory ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com ___ 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
