Hi I did the check with "-verbose:gc" on the TickTockCollision demo and indeed, the short 'stops' coincide with the triggered garbage collector (until now, I thought the collision detector was responsible for that !). Thanks for the hint ! Question: Is there some way, to switch the GC on and off programmatically ? If there is, one could activate the GC when rendering wouldn't be (visually) influenced. Smooth rendering should be one main goal of Java 3D - without timing the scene updates! When Java 3D will be compared to other 3D API's, short 'stops' won't make a good impression... J. Winter [EMAIL PROTECTED] -----Ursprüngliche Nachricht----- Von: Doug Gehringer <[EMAIL PROTECTED]> An: [EMAIL PROTECTED] <[EMAIL PROTECTED]>; [EMAIL PROTECTED] <[EMAIL PROTECTED]> Datum: Saturday, January 16, 1999 1:12 AM Betreff: Re: [java3d] has the update frequency of the scene graph a limit ? > > >> From: "Pascal Debarge" <[EMAIL PROTECTED]> >> >> I am currently updating the position and the behavior of each >> character (about 40) 15 times per second. >> The problem is that the renderer seems to be stucked every 1 or 2 >> seconds during >> 200 or 300 milliseconds. Even if I reduce the update rate to 1 per >> second, >> the problem is the same. > >So, if I understand you right, the renderer is displaying frames at a reasonable >rate, but every one or two seconds you get a 200-300 millisecond pause? This >sounds like the garbage collector is running. Try running java with >"-verbose:gc" to see if the gc messages coincide with your pauses. > >If gc is the culprit, then you can speed things up by reducing your memory "burn >rate". Try to reuse objects instead of creating them with each frame. Since you >are modifying transforms with each frame, make sure you re-use the transforms >instead of creating new ones. > >Early in the Java3D development process the team was able to significantly >increase frame rates and decrease "jitter" by carefully managing memory. > >Also, increasing your initial heap size using the -Xms option can reduce the >problem by making the gc have more room to cleanup. Try "-XmsXXXm -XmxXXXm" >where XXX is the maximum amount of real memory your Java application can use. >Note that this doesn't reduce the amount of time spent in GC (unless your >application is just a bit smaller than the max heap size), but instead makes >your do fewer GCs, each of which takes longer. > >BTW, how many frames a second are you getting (use View.getFrameStartTimes() or >View.getLastFrameDuration() to tell). It doesn't make much sense to update the >scene more often than the renderer can render it. > >Doug Gehringer >Sun Microsystems > >===================================================================== >To subscribe/unsubscribe, send mail to [EMAIL PROTECTED] >Java 3D Home Page: http://java.sun.com/products/java-media/3D/ > ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ To subscribe/unsubscribe, send mail to [EMAIL PROTECTED] Java 3D Home Page: http://java.sun.com/products/java-media/3D/
