# Problems using JBullet engine

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m41q    151
Hi,

I was searching for a good physics engine, when I discovered JBullet, a java port of Bullet; compatible with LWJGL.
The problem with JBullet is, that LWJGL got updated, and JBullet not, for a long time:
LWJGL now doesn´t support "indirect Buffers" anymore and JBullet uses them; for that problem I found this solution:
[url="http://blog.lolyco.com/sean/2011/05/14/trying-out-jbullet-intbuffer-is-not-direct/"]http://blog.lolyco.com/sean/2011/05/14/trying-out-jbullet-intbuffer-is-not-direct/[/url]
This guy fixed the problem and recompiled JBullet.jar.

When I tried to do this, I got some errors and was able to solve most of them, but now I get an error when compiling using the ant-script that goes with JBullet. I neither understand it, nor a soultion on the internet was to be found:
[CODE]
BUILD FAILED
D:\workspace\J-workspace\JBullet\build.xml:77: java.lang.IllegalStateException: can't find set method for class java.lang.Object
[/CODE]
build.xml: 77 refers to the ant-script, relevant section here:
[CODE]
<target name="instrument-classes">
classpath="${run.classpath}"> </taskdef> <!-- Next line is important: --> <instrument-stack dest="${build.classes.dir}" packageName="com.bulletphysics" isolated="true">
<fileset dir="\${build.classes.dir}" includes="**/*.class"/>
</instrument-stack>
</target>
[/CODE]

I never worked with ant-files before and couldn´t find a solution for this error.

[size=4][b]Now my question is[/b], could anyone[/size]
[size=4]- tell me what I got wrong with the ant-file OR[/size]
[size=4]- tell me how I can get JBullet working in another way OR[/size]
[size=4]- has anyone got an idea of anohter physics engine working with Java?[/size]

(Btw. I know the issue would be solved if I downgraded LWJGL from 2.8.3 to 2.2.2, but that is currently not an option.)

So, has anyone got an idea, please?

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jjd    2140
Hi m41q,

Unfortunately, I don't know the answer to your problem, but I would suggest that you talk to the developers of LWJGL because this may be an issue they are unaware of. In particular, transitioning from 2.2 to 2.8 is a minor update that should be backwards compatible and it sounds like that is not the case.

Also, this is topic is probably better suited for 'game programming' or 'general programming' than in the maths and physics forum, so you might find more help there.

-Josh Edited by jjd

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m41q    151
First of all thx for the reply.
But I think I´m afraid I saw a post somewhere, stating that those indirect buffers are no longer supported because of stability issues, so chances that they will support them again are little : (

[quote name='jjd' timestamp='1338212204' post='4944010']
better suited for 'game programming' or 'general programming'
[/quote]
I just thought in the physics section had to be more people that are knowing physics engines?