Error in scene!
(java.lang.OutOfMemoryError: Java heap space)
is the error I get when I try to open a scene where I had been playing around with some terrain after restarting the SDK. I have 2gb of memory; is it a problem with my amount memory, or the way which the SDK is set up on my computer?
You’re running out of heap space… You can change the amount of memory allocated to the Java heap in installation directory/etc/jmonkeyplatform.conf
EDIT: oops, I made a typo 
That should be etc/jmonkeyplatform.conf
hrm… So I am looking at this file, and am not sure what to change; I assume that I want to increase either of the 2 bolded sizes, but I am not sure which one.
default_options="–branding jmonkeyplatform -J-Xms24m -J-Xmx512m -J-XX:PermSize=256m -Dsun.java2d.noddraw=true -Dsun.awt.noerasebackground=true -Dsun.java2d.d3d=false -Dsun.java2d.opengl=false -Dsun.java2d.pmoffscreen=false"
I did some googling and read up on it; if anybody stumbles on this thread, http://javarevisited.blogspot.com/2011/05/java-heap-space-memory-size-jvm.html might help you.
Sorry… was replying quickly and should have specified… Xmx is what you’d want to raise as that is the maximum heap size. PermGen memory is different and the JVM would give you a similar error message indicating that it was out of it (Same goes for direct memory, which is where jME stores its buffers)
Make sure you have the latest stable updates installed.