On Saturday 01 March 2008 at 20:06:02, [EMAIL PROTECTED] wrote: > Benjamin Eikel wrote: > > Hello Robert, > > > > On Saturday 01 March 2008 at 18:50:16, Robert Osfield wrote: > >> Hi Benjamin, > >> > >> Could you possibly repost the below text, but broken down into shorter > >> paragraphs as long paragraphs are really hard to follow. Try to keep > >> one major point per paragraph. > > > > of course. > > > > o What do we want to display? > > We want to visualize scenes which are generated by a simulation of a > > factory. > > > > o Why do we want to use a cluster? > > The simulation is running on a cluster. We want to do the rendering on > > the cluster because > > - we can get messages from the simulation faster (10 GBit/s > > InfiniBand, lower latency than Ethernet, DMA transfers from one node to > > another) > > - we are able to cope with big scenes by just using more rendering > > nodes (at least that is our goal). > > - we have the computation power there. > > > > o Why do we have big scenes? > > Models of some machines are very complex because they are generated by > > CAD programs and we do not want to do an extensive preprocessing because > > the models may change over time. > > > > o What is the architecture of the system? > > - We have a central node for each user which is connected to our system. > > On that node we want to use OpenSceneGraph (reasons below). So each of > > these nodes has an own view into the scene. > > - We have a set of rendering nodes. These rendering nodes are partitioned > > by a balancing algorithm and each central node gets some of them for > > rendering. We want to balance between different users and between the > > rendering nodes one central node is able to render with. > > Example: User A sees only a small part of the factory => needs only few > > rendering nodes. User B sees some very complex machines => needs lots of > > rendering nodes. > > Example: Central node A can render with 20 rendering nodes. It has 20 > > objects with 1 million polygons and so it gives each rendering node one > > object. > > > > o How to we get the scene data from the simulation? > > We get a identification number for each machine mesh from the simulation. > > We then want to load the meshes for that machine inside the scene graph. > > > > o Why do we want to use OpenSceneGraph? > > - We can use the already existing reader/writer plugins of OSG and do not > > have to write our own. > > - OSG can do culling, picking, moving machines with grabbers for us. > > - We want to use the animation capabilities of OSG for some special > > models (e. g. forklifts, packages on a conveyor). > > > > o How will OpenSceneGraph be connected to the rendering nodes? > > When a frame should be rendererd we want to know the nodes (e. g. Geodes) > > which are visible and their transformation matrix (which should be known > > to OSG after it's update and culling traversals). With this knowledge > > (list of visible nodes and transformations) the central nodes instruct > > their rendering nodes by sending them the mesh ids, the transformations > > of the meshes and the camera transformation. > > > > o How can we optimize the rendering on the rendering nodes? > > We want to exploit the fact that there may be the same machine (= same > > mesh) multiple times inside the factory. So we could load the mesh of > > such a machine as VBO and let one rendering node render the machines with > > different transformations multiple times. > > > > o What is my question at all? > > I am searching for a interface where I can grab these visible nodes and > > put them into a list. I need them so I can analyse them to run the > > balancing algorithm and send the data to the rendering nodes. I think > > that it might be possible to use the DrawImplementation of the Drawable > > nodes. > > this is not an answer to your questions about your interesting project, > only some thoughts about engineering stuff and simulation. > > http://www.realityprime.com/articles/scenegraphs-past-present-and-future#to >morrow http://www.caelinux.com/CMS/ > what i didn´t find is a realtime grid for the balancing stuff. > > are there more infos about the project, maybe on a website? Hello Hannes (I suppose),
the website of our project group is here: http://wwwhni.uni-paderborn.de/alg/lehre/ebkfs/remosim/ But it is only available in German I am sorry. Another project which is a little bit connected to ours is this (English description available): http://wwwhni.uni-paderborn.de/en/alg/projects/avipasia/ > > best wishes for your success! Thank you very much. Regards, Benjamin > > _______________________________________________ > 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
