DOTS的迭代与安装变迁

DOTS跟随着Unity的Package Manager发布，使得最开始学习DOTS只需下载安装Entities包即可。
但是现在（作者从Unity 2020.1开始）Entities包不再在Package Manager直接提供，即便打开Unity内部的Edit->Project Setting->Package Manager->Enable Preview Packages选项也无济于事。
Unity官方给出一份列表，将其移除出了预览名单，再需要添加均需要使用Package Manager中的Add package from git URL...：

com.ptc.vuforia.engine
com.unity.2d.entities
com.unity.ai.planner
com.unity.aovrecorder
com.unity.assetbundlebrowser
com.unity.assetgraph
com.unity.barracuda
com.unity.barracuda.burst
com.unity.build-report-inspector
com.unity.cloud.userreporting
com.unity.collections
com.unity.connect.share
com.unity.dots.editor
com.unity.entities
com.unity.film-tv.toolbox
com.unity.google.resonance.audio
com.unity.immediate-window
com.unity.mathematics
com.unity.meshsync
com.unity.multiplayer-hlapi
com.unity.package-manager-doctools
com.unity.package-manager-ui
com.unity.package-validation-suite
com.unity.physics
com.unity.platforms
com.unity.platforms.android
com.unity.platforms.linux
com.unity.platforms.macos
com.unity.platforms.web
com.unity.platforms.windows
com.unity.playablegraph-visualizer
com.unity.render-pipelines.lightweight
com.unity.rendering.hybrid
com.unity.renderstreaming
com.unity.scene-template
com.unity.simulation.client
com.unity.simulation.core
com.unity.simulation.capture
com.unity.simulation.games
com.unity.standardevents
com.unity.streaming-image-sequence
com.unity.test-framework.performance
com.unity.tiny.all
com.unity.transport
com.unity.upm.develop
com.unity.vectorgraphics
com.unity.webrtc
com.unity.xr.googlevr.android
com.unity.xr.googlevr.ios
com.unity.xr.legacyinputhelpers
com.unity.xr.oculus.android
com.unity.xr.oculus.standalone
com.unity.xr.openvr.standalone
com.unity.xr.arsubsystems
com.unity.xr.interactionsubsystems
com.unity.xr.windowsmr.metro

具体内容在连接https://forum.unity.com/threads/visibility-changes-for-preview-packages-in-2020-1.910880/内可查询