Does Unreal 4 support "simple Lightmap" modification textures for mobile?

I’ve dug around a bit in the engine and internet searches for documentation/questions but I haven’t found anything.
Its a useful and extremely cheap way to get a lot of texture variation without having to do expensive material blending.

Thanks for any info.


I’m not sure I fully understand what you’re asking.

What are you meaning by Lightmap Modification? With UE4 this is done with an external modeling program or stand alone UV program?

UE4 does have the ability to generate a LM channel for shadow baking though via the Mesh Viewer/Editor.

Although, your question doesn’t so much indicate you want to adjust the lightmaps as it does working with Materials and the diffuse UV.

Can you clarify with images or examples?

Thank you!


Hi Tim, I apologize for not explaining this feature. It was in UDK.
In the Mobile Settings section of a level objects properties was a checkbox called “Simple Lightmap Modifications”

If you slot an image from the content browser in there, the objects lightmap would have the image blended onto it. This was a super cheap way to add per-object color variation and grime masks. It was used in the epic citadel demo to add grime to the castle walls. It only works for non-directional or “simple” lightmaps and only on mobile. Do you know if this feature never made it to ue4?

This feature did not make it into UE4 and likely never will. The reason being how lights are handled now. UE4 uses a Deferred Rendering path which means that lights are baked after the materials, whereas UE3/UDK used a forward rendering path where lights were baked before materials.


I must have missed your response. Thank you for looking into it anyway.