Sounds like a CAD application. Look into occlusion culling and imposters. 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. • [email protected] wrote: ----- To: [email protected] From: Andrew Burnett-Thompson <[email protected]> Sent by: [email protected] Date: 07/12/2009 05:12PM Subject: [osg-users] Rendering Performance and Proper Way to have millions of moveable objects Hi Robert, Thanks for your reply. Yes I did guess that I'm using the scene graph wrong. Fortunately with regard to our scene, while we have a lot of objects, the detail is not significant. The application allows users to simulate certain conditions that would occur in an industrial plant. So long as the model is a crude reflection of the plant it works, so we are already significantly optimising geometry. Rendering is only required as the user moves around the plant, or if an object is manipulated. During render we are currently hiding the smallest 50% of objects, which works remarkably well to improve usability (A full re-draw is performed when the user stops moving), but still the frame rate drops below interactive levels depending on how many objects remain. With regard to flattening of static transforms - how exactly would we do this? I was thinking to put a PAT as parent of a geode only while the user is picking/manipulating it, then remove it after, somehow matrix-multiplying the transform with vertices to get the new position. Is this possible? With regard to LOD's - sounds like a good plan but I think this may end up using more memory (which is an issue) even though it improves rendering performance. Paging does interest me though. I already set the cull settings to ENABLE_ALL_CULLING. I noticed that shadow occlusion (which I believe means when a large object occludes the camera, objects behind it are culled?) seems to have no effect. Is this due to my flat scene graph? View frustrum culling seems to have the largest effect. With regard to efficiently managing the scene graph (having a balanced tree), thanks for confirming that. I did have a hunch that would be the case but its nice to know. With regard to state sharing - is it possible to have one state object on multiple geodes? Or did you mean have multiple statesets with similar states? Cheers for the feedback much appreciated, Andrew _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
