LOD Recipe: Use existing source LOD

Use LOD Recipe to create a LOD chain using an existing LOD as source instead of using the default LOD 0. An existing source LOD could be an imported LOD.

Prerequisites:

• A Skeletal or Static mesh which contains a source LOD.
• A LOD Recipe containing at least one Skeletal Mesh and/or a Static Mesh.

WARNING

A generated LOD using the built-in reduction interface is not considered a source LOD

1. Enable Use Imported LOD

In the LOD Recipe, go to Miscellaneous Settings → LOD 1 and enable Use Imported LOD. This is to avoid the LOD to be overwritten during processing and instead preserve the existing source LOD.

Figure 1: Enable Use Imported LOD.

2. Set Base LOD index

Next step is to make sure the LOD chain is using LOD 1 as the base when generating LODs. For the rest of the LODs in the LOD Recipe, set Base LOD index to 1.

Figure 2: Search for Base LODIndex. Set base lod index to 1 for LOD 2 and LOD 3.

3. (Optional) Adjust settings

In this example we have adjusted these settings:

• LOD 2 (Reduction Pipeline)
  • Triangle Ratio: 0.5
• LOD 3 (Reduction Pipeline)
  • Triangle Ratio: 0.25

4. Build

Once you're done setting all the LOD Recipe settings, press build and wait for the process to complete.

5. Result

Figure 3 shows the outcome of reusing an existing source LOD (LOD 1) as the base for generating the rest of the LOD chain. By setting LOD 1 as the source LOD, it is preserved and not overwritten during processing. LOD 1 becomes the starting point for subsequent LODs (LOD 2 and LOD 3), ensuring the original imported LOD remains intact and is used as the foundation for further optimizations.

Figure 3: Result using existing source LOD 1 as base for LOD 2 and LOD 3.