# Arcball Library error

**URL:** <https://discourse.processing.org/t/arcball-library-error/17292>\
**Category:** Libraries\
**Created:** [January 23, 2020, 7:12pm UTC](https://discourse.processing.org/t/arcball-library-error/17292 "2020-01-23T19:12:35Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![paulstgeorge](https://avatars.discourse-cdn.com/v4/letter/p/53a042/32.png) [@paulstgeorge](https://discourse.processing.org/u/paulstgeorge)\
**Post date:** [January 23, 2020, 7:12pm UTC](https://discourse.processing.org/t/arcball-library-error/17292/1 "2020-01-23T19:12:35Z")

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I tried to use the Arcball library [https://github.com/RandomEtc/processing-arcball](https://github.com/RandomEtc/processing-arcball)

I get the error: java.lang.NoSuchMethodError:processing.core.PApplet.registerMouseEvent(Ljava/lang/Object;)V

Does this mean a core processing method is missing? Perhaps a core processing method that was part of an earlier version of Processing?

If my guess is wrong, what does this error mean?

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**Author:** ![monkstone](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/monkstone/32/64_2.png) [@monkstone](https://discourse.processing.org/u/monkstone)\
**Post date:** [January 23, 2020, 8:41pm UTC](https://discourse.processing.org/t/arcball-library-error/17292/2 "2020-01-23T20:41:46Z")

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See my [Arcball gem](https://github.com/ruby-processing/ArcBall/blob/master/src/monkstone/arcball/Arcball.java) that I use for my ruby-processing projects PiCrate and propane should be easy to adapt for vanilla processing. See `setActive` method for how to register Mouse Events since processing-3.

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**Author:** ![GoToLoop](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/gotoloop/32/86_2.png) [@GoToLoop](https://discourse.processing.org/u/GoToLoop)\
**Post date:** [January 23, 2020, 11:35pm UTC](https://discourse.processing.org/t/arcball-library-error/17292/3 "2020-01-23T23:35:18Z")

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> [@paulstgeorge](#):
>
> Does this mean a core processing method is missing?

**registerMouseEvent()** was deprecated on P2 and removed on P3

All such methods were replaced by **registerMethod()**:  
[Processing.GitHub.io/processing-javadocs/core/processing/core/PApplet.html#registerMethod-java.lang.String-java.lang.Object-](http://Processing.GitHub.io/processing-javadocs/core/processing/core/PApplet.html#registerMethod-java.lang.String-java.lang.Object-)

Therefore, that library isn’t compatible w/ Processing 3. You’re gonna need Processing 2 or down.

However, given you’ve got access to its source code:

> <https://github.com/RandomEtc/processing-arcball/blob/master/Arcball.java#L63-L64>

You can simply make the necessary modifications to those method calls within the code.

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**Author:** ![paulstgeorge](https://avatars.discourse-cdn.com/v4/letter/p/53a042/32.png) [@paulstgeorge](https://discourse.processing.org/u/paulstgeorge)\
**Post date:** [January 24, 2020, 11:15am UTC](https://discourse.processing.org/t/arcball-library-error/17292/4 "2020-01-24T11:15:50Z")

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> [@GoToLoop](#):
>
> simply make the necessary modifications

😉

Thank you both. I am actually trying to make a virtual trackball without using a Library. See [Gimbals, quaternions, and manual rotation](https://discourse.processing.org/t/gimbals-quaternions-and-manual-rotation/17065)

I am almost there and just wanted to look at Arcball to see what might be useful.