Using LOD Groups
Using LOD Groups is the preferred way to create LODs inside UE4 with the Automatic LOD tool. In the following section, we will go over how you go about setting up and using LOD groups in your UE4 projects.
First, locate your project's BaseEngine.ini file and open it up inside of a Text editor. Now, look for the
[StaticMeshLODSettings] section. If you do not see this entry in your BaseEngine.ini file, copy and paste the following code into your BaseEngine.ini file.
Adding, removing, or adjusting entries from this section will add, remove, or adjust how the LOD groups function when they're used.
Now, open the UE4 Editor and then open up a Static Mesh you want to generate LODs for by double-clicking on it in the Content Browser. For this example, we will be using SM_Rock, which comes with the Starter Content.
With the Static Mesh now open in the Static Mesh Editor, go to the Details panel and expand the LOD Settings section.
In the LOD Settings section, click on the LOD Group button, and from the displayed list, select the SmallProp option.
You will then be notified that what you are doing will overwrite your current settings with the new setting from SmallProp. Press the Yes button to continue.
The Static Mesh Editor should now have four new LOD entries (LOD0, LOD1, LOD2, and LOD3) added to the Details panel. If you click on each LOD entry, you will notice that the settings correspond to the settings that were defined in the
StaticMeshLODSettings in your project's BaseEngine.ini file.
Make sure Auto Compute LOD Distances is checked, as it will help in determining which screen size to use for the LOD. Because the algorithm knows how much visual difference every edge collapse is adding, it can use this information to determine what distance that amount of error is acceptable. Turning this off, means that the screen size for each LOD needs to be set by hand, which could lead to errors.
Now, experiment with the different LOD Group settings to see how they will create LODs for your objects. In the next section, we will go over how to manually create LODs.