预览包尚未验证是否可以安全地与当前 Unity 版本一起使用，因此，只能将预览包用于测试和提供反馈。在将来的某个时候，预览包可能会通过验证要求；但是，它们也可能被弃用。由于不能保证将来会获得支持，因此不得在实际生产中使用任何带有 preview 指示符号的包。有关包的预览状态和生命周期的更多信息，请参阅包状态和生命周期。
有关已验证可用于 2019.4 的稳定包的列表，请参阅已验证包。
单击以下任何链接可以查看相应包的文档。
[com.unity.2d.entities]：http://docs.unity3d.com/Packages/com.unity.2d.entities@0.22/manual/index.html target=“blank“ [com.unity.2d.ik]：http://docs.unity3d.com/Packages/com.unity.2d.ik@2.0/manual/index.html target=”blank” [com.unity.ai.planner]：http://docs.unity3d.com/Packages/com.unity.ai.planner@0.2/manual/index.html target=“blank“ [com.unity.animation.rigging]：http://docs.unity3d.com/Packages/com.unity.animation.rigging@0.2/manual/index.html target=”blank” [com.unity.assetgraph]：http://docs.unity3d.com/Packages/com.unity.assetgraph@1.6/manual/index.html target=“blank“ [com.unity.build-report-inspector]：http://docs.unity3d.com/Packages/com.unity.build-report-inspector@0.2/manual/index.html target=”blank” [com.unity.cinemachine]：http://docs.unity3d.com/Packages/com.unity.cinemachine@2.6/manual/index.html target=“blank“ [com.unity.testtools.codecoverage]：http://docs.unity3d.com/Packages/com.unity.testtools.codecoverage@0.3/manual/index.html target=”blank” [com.unity.collections]：http://docs.unity3d.com/Packages/com.unity.collections@0.9/manual/index.html target=“blank“ [com.unity.device-simulator]：http://docs.unity3d.com/Packages/com.unity.device-simulator@2.2/manual/index.html target=”blank” [com.unity.dots.editor]：http://docs.unity3d.com/Packages/com.unity.dots.editor@0.7/manual/index.html target=“blank“ [com.unity.entities]：http://docs.unity3d.com/Packages/com.unity.entities@0.11/manual/index.html target=”blank” [com.unity.formats.fbx]：http://docs.unity3d.com/Packages/com.unity.formats.fbx@3.2/manual/index.html target=“blank“ [com.unity.film-tv.toolbox]：http://docs.unity3d.com/Packages/com.unity.film-tv.toolbox@0.2/manual/index.html target=”blank” [com.unity.game.foundation]：http://docs.unity3d.com/Packages/com.unity.game.foundation@0.4/manual/index.html target=“blank“ [com.havok.physics]：http://docs.unity3d.com/Packages/com.havok.physics@0.2/manual/index.html target=”blank” [com.unity.rendering.hybrid]：http://docs.unity3d.com/Packages/com.unity.rendering.hybrid@0.5/manual/index.html target=“blank“ [com.unity.immediate-window]：http://docs.unity3d.com/Packages/com.unity.immediate-window@1.1/manual/index.html target=”blank” [com.unity.jobs]：http://docs.unity3d.com/Packages/com.unity.jobs@0.2/manual/index.html target=“blank“ [com.unity.kinematica]：http://docs.unity3d.com/Packages/com.unity.kinematica@0.6/manual/index.html target=”blank” [com.unity.memoryprofiler]：http://docs.unity3d.com/Packages/com.unity.memoryprofiler@0.2/manual/index.html target=“blank“ [com.unity.meshsync]：http://docs.unity3d.com/Packages/com.unity.meshsync@0.1/manual/index.html target=”blank” [com.unity.ml-agents]：http://docs.unity3d.com/Packages/com.unity.ml-agents@1.1/manual/index.html target=“blank“ [com.unity.xr.mock-hmd]：http://docs.unity3d.com/Packages/com.unity.xr.mock-hmd@1.0/manual/index.html target=”blank” [com.unity.upm.develop]：http://docs.unity3d.com/Packages/com.unity.upm.develop@0.1/manual/index.html target=“blank“ [com.unity.package-validation-suite]：http://docs.unity3d.com/Packages/com.unity.package-validation-suite@0.11/manual/index.html target=”blank” [com.unity.test-framework.performance]：http://docs.unity3d.com/Packages/com.unity.test-framework.performance@2.2/manual/index.html target=“blank“ [com.unity.platforms]：http://docs.unity3d.com/Packages/com.unity.platforms@0.4/manual/index.html target=”blank” [com.unity.platforms.android]：http://docs.unity3d.com/Packages/com.unity.platforms.android@0.4/manual/index.html target=“blank“ [com.unity.platforms.linux]：http://docs.unity3d.com/Packages/com.unity.platforms.linux@0.4/manual/index.html target=”blank” [com.unity.platforms.macos]：http://docs.unity3d.com/Packages/com.unity.platforms.macos@0.4/manual/index.html target=“blank“ [com.unity.platforms.web]：http://docs.unity3d.com/Packages/com.unity.platforms.web@0.4/manual/index.html target=”blank” [com.unity.platforms.windows]：http://docs.unity3d.com/Packages/com.unity.platforms.windows@0.4/manual/index.html target=“blank“ [com.unity.playablegraph-visualizer]：http://docs.unity3d.com/Packages/com.unity.playablegraph-visualizer@0.2/manual/index.html target=”blank” [com.unity.progrids]：http://docs.unity3d.com/Packages/com.unity.progrids@3.0/manual/index.html target=“blank“ [com.unity.tiny.all]：http://docs.unity3d.com/Packages/com.unity.tiny.all@0.26/manual/index.html target=”blank” [com.unity.streaming-image-sequence]：http://docs.unity3d.com/Packages/com.unity.streaming-image-sequence@0.2/manual/index.html target=“blank“ [com.unity.terrain-tools]：http://docs.unity3d.com/Packages/com.unity.terrain-tools@3.0/manual/index.html target=”blank” [com.unity.ui.builder]：http://docs.unity3d.com/Packages/com.unity.ui.builder@0.11/manual/index.html target=“blank“ [com.unity.aovrecorder]：http://docs.unity3d.com/Packages/com.unity.aovrecorder@0.1/manual/index.html target=”blank” [com.unity.purchasing.udp]：http://docs.unity3d.com/Packages/com.unity.purchasing.udp@2.0/manual/index.html target=“blank“ [com.unity.netcode]：http://docs.unity3d.com/Packages/com.unity.netcode@0.2/manual/index.html target=”blank” [com.unity.physics]：http://docs.unity3d.com/Packages/com.unity.physics@0.3/manual/index.html target=“blank“ [com.unity.recorder]：http://docs.unity3d.com/Packages/com.unity.recorder@2.2/manual/index.html target=”blank” [com.unity.reflect]：https://docs.unity3d.com/reflect/manual/index.html target=“blank“ [com.unity.renderstreaming]：http://docs.unity3d.com/Packages/com.unity.renderstreaming@2.0/manual/index.html target=”blank” [com.unity.simulation.client]：http://docs.unity3d.com/Packages/com.unity.simulation.client@0.0/manual/index.html target=“blank“ [com.unity.simulation.core]：http://docs.unity3d.com/Packages/com.unity.simulation.core@0.0/manual/index.html target=”blank” [com.unity.transport]：http://docs.unity3d.com/Packages/com.unity.transport@0.3/manual/index.html target=“blank“ [com.unity.cloud.userreporting]：http://docs.unity3d.com/Packages/com.unity.cloud.userreporting@0.2/manual/index.html target=”blank” [com.unity.formats.usd]：http://docs.unity3d.com/Packages/com.unity.formats.usd@1.0/manual/index.html target=“blank“ [com.unity.vectorgraphics]：http://docs.unity3d.com/Packages/com.unity.vectorgraphics@2.0/manual/index.html target=”blank” [com.unity.connect.share]：http://docs.unity3d.com/Packages/com.unity.connect.share@2.0/manual/index.html target=“blank“ [com.unity.webrtc]：http://docs.unity3d.com/Packages/com.unity.webrtc@2.0/manual/index.html target=”blank” [com.unity.xiaomi]：https://unity3d.com/partners/xiaomi/guide?_ga=2.256552962.861115613.1571082168–389247850.1524252825 target=“blank“ [com.unity.xr.interaction.toolkit]：http://docs.unity3d.com/Packages/com.unity.xr.interaction.toolkit@0.9/manual/index.html target=”blank”