No documentation on the HLOD feature

[Tim_Hobson]

@motorsep;547222

Could you please outline the workflow and how to set up BP for instanced HLOD static meshes and foliage? (I generate LODs with InstaLOD directly in UE4 and Blender outside of UE4)

I get it, you guys are busy, but how do you expect us, indie devs, to take advantage of optimization features if there are no docs, not even write ups on blogs or this forum?!

You can enable HLODs via the World Settings (Map specific).

Then you can go to Window > Hiearchical LOD Outliner to open up its settings window.

Here you can generate all your LODs and clusters. This window may seem overwhelming, but it’s not all the difficult to figure out if you play around with the settings.

Step 1.

You’ll start by setting up your LODs (bottom panel) and all the various settings you’ll want for them. The biggest thing to pay attention to in the inividual LOD settings i the Desired Bounds Radius. Use smaller values to start out with until you see how it works. Something like HLOD Level 0 uses 250 and HLOD Level 1 will use 500 are good because these bounds are essentially just a 250cm and 500cm bounding sphere that group meshes in these sized chunks. Not all meshes are guaranteed to be in the sphere, but it’s just an easy way to capture a cluster of actors.

**Step 2. **

Once you’ve set up your LODs, you can then hit the generate clusters button at the top. This will take a few minutes depending on the settings you used in the bottom LODs section and how many actors you have in your scene.

When this finished you’ll see the clusters populate the middle window. You can then select the individual LODs and see what actors were clusters in that particular LOD. You can use the slider at the top for “Forced Viewing Level” to see how your different HLODs will work.

Step 3.

If you’re happy with your Generated HLODs you can now hit the Generate Proxy Meshes button. This will now convert all those HLODs into assets located in your project folder under HLODs. These static mesh actors can not be opened and edited if needed.

Limitations and caveats:

• Cannot use movable objects
• Blueprints with many meshes will have a larger bounds than individual actors so if you’re HLOD uses a smaller desired radius it will not be included in a HLOD.
• Merged materials do not support the alpha channel. You will have to set this part up manually or not merge the materials for these types of actors.
• HLODs do not decimate your meshes. You will need thirdparty software like Simplygon which is integrated and works. (Not sure about InstaLOD that you mention you are using)
• Doesn’t work with instanced meshed painted with the foliage tool.

I hope this tides you over until there is some official documentation.

Tim