Re: [osg-users] Advice sought for rendering coins in OSG. Lots ofcoins.
Hi Christian, Looks great! The behaviour of the coins is spot on. It's crying out for some shiny shaders though.. Kim. -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Christian Buchner Sent: 21 June 2009 23:53 To: OpenSceneGraph Users Subject: Re: [osg-users] Advice sought for rendering coins in OSG. Lots ofcoins. To profile the peformance bottleneck it would be best to press 's' a couple more times to get the full frame rate stats so you can see exactly which parts of rendering are the bottleneck - the frame rate only tells that you frame rate is reducing it doesn't give any clues to why. I am pretty sure I am limited by the physics. Right now I have to reduce the physics time step dynamically to stay within my tolerated frame rate window. A final video (I promise!) is posted here and it shows an almost complete pusher machine and up to 400 coins in the game. http://www.youtube.com/watch?v=0bLAq7btZbUfmt=22 I have since made the pusher operate faster so the player won't fall asleep. I still have to add the game mechanics (player's coin balance, player controlled coin insertion etc). My coins are currently rendered several OSG PositionAttitudeTransforms, all from the same model instance. I may switch to an approach that uses vertex shaders soon. A future enhancement could put the physics on a separate thread from OSG. We will see how that goes. Christian ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g* To view the terms under which this email is distributed, please go to http://www.hull.ac.uk/legal/email_disclaimer.html *___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Advice sought for rendering coins in OSG. Lots ofcoins.
Think of BRDFs as Imposters on steroids. The idea is to have views of an object from several different angles, and let the hardware choose which one (or ones) to use to represent the object based on the current view direction. The visual representation is on par with Imposters, so it is quite 3D. Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com +1 303 859 9466 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Advice sought for rendering coins in OSG. Lots ofcoins.
- things get slow with more than 70 coins on this (slightly outdated) machine. The bottleneck is definitely physics, not rendering. May have to experiment with CUDA acceleration to achieve 500 coins and more. I suspect your bottleneck if with solving. Currently, the Cuda solver is not yet open source. The (already available) Cuda dispatcher probably won't help your performance. - The coins slide apart when stacked on top, as if the whole setup was on a vibrating ground plate. I need to get in touch with the guys on the bullet physics forums to see if this can be solved. By default, Bullet should perform multiple samples (10, I think, per sim step) in the solver to compensate for this. Is your app explicitly setting this down to fewer samples for performance reasons? -Paul ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Advice sought for rendering coins in OSG. Lots ofcoins.
Hi Paul, Is your app explicitly setting this down to fewer samples for performance reasons? Assuming dt, is the time between 2 frames, I call stepSimulation(dt, 20, 0.005); // 200 ticks per second, minimum 10 FPS assumed I will be taking the physics related discussion to the proper forums, because I think it is off-topic for osg-users. I describe some of my settings and assumptions in the post linked below. http://www.bulletphysics.com/Bullet/phpBB3/viewtopic.php?f=9t=3623start=0 Thanks for your interest, Christian ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
