From Entity Component System – DOTS Project Setup
Starting with Unity 2020.1, the DOTS packages are not listed in the package manager, even when preview packages are enabled. There are two alternative options to install those packages:
- You can use
"Add package from git URL..."under the + menu at the top left of the package manager to add packages either by name (such as
com.unity.entities), or by git URL (but this option isn’t available for DOTS packages). Note that it might take a few moments before the package starts installing.
- Alternatively, you can add DOTS packages by directly editing the
Packages\manifest.jsonfile in your project. This file requires not only the package name but also a version which can be found by looking at the documentation of each package (such as
"com.unity.entities" : "x.x.x-preview.x").
For example currently it would be
com.unity.entities" : "0.17.0-preview.41"
Follow the link for more information about installing hidden packages.
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The recommended set of core packages to be added to a DOTS project is: