org.scijava:j3dcore

Java 3D Core

This is a Mavenized version of the latest Java 3D j3dcore component, built on JOGL 2.x, with a renamed package prefix to avoid conflicts with old versions of Java 3D.

Background and rationale

Historically, Java 3D was installed as an extension to the Java Runtime Environment, meaning that JAR files and native libraries were placed in the lib/ext directory of the JRE installation, or manually appended to the Java extensions via the java.ext.dirs system property.

However, that approach has many downsides:

• Users must install Java 3D manually, independent of the application.
• Thus, at runtime, the application cannot manage the version of Java 3D in the same was that it manages versions of its regular dependencies.
• Similarly, at build time, the Java 3D dependency must be treated specially (e.g., with Maven, using provided scope in the POM).

These days, Java 3D 1.6 is built on top of JOGL 2.x, and available on GitHub. But old installations of Java 3D still lurk, waiting to disrupt applications at runtime: libraries present on the Java extensions path take precedence over those on the regular class path.

Failure to manage Java 3D installations as needed can result in cryptic version-skew-related error messages, such as NoSuchMethodError or even native-library-related errors, including JVM crashes. This situation is especially prevalent on OS X, where Java 3D 1.3 was pre-installed in /System/Library/Java/Extensions on older versions of the OS, and left in place after OS upgrades (despite Java itself being uninstalled).

Furthermore, OS X 10.11 "El Capitan" introduced a new security feature called System Integrity Protection (SIP) which prevents users from deleting the obsolete Java 3D libraries from /System/Library/Java/Extensions. And the default extensions path of Oracle Java 8 includes this directory, making it impossible to use Java 3D with Java 8 out of the box in this scenario.

This fork of Java 3D avoids the issue by changing the package prefix, so that legacy code can be easily refactored to use it without danger from the obsolete versions of Java 3D.

Project status

This project is a temporary fork, until upstream Java 3D makes some progress. See: Java 3D: Use Maven to build, and publish Maven artifacts

How to use it

To use from your Maven project, add the following dependency to your POM:

<dependency>
	<groupId>org.scijava</groupId>
  <artifactId>j3dcore</artifactId>
  <version>1.6.0-scijava-2</version>
</dependency>

Related projects

• https://github.com/scijava/java3d-utils
• https://github.com/scijava/vecmath