Lightmap Resolution vs Min Lightmap Resolution

Could anyone explain to me the difference between Min Lightmap Resolution (Under Build Settings) and Lightmap Resolution (under Static Mesh Settings) when editing a static mesh object?

I know that increasing these values helps increase the quality of my shadows, but I don’t know when I should be altering one and leaving the other alone, so I end up increasing both simultaneously. That ends up feeling like I’m doing something horribly inefficient.

Any help would be appreciated.

Hi Hypersapian,

Min Lightmap Resolution is the target lightmap resolution you want to generate the UV for the lightmap for and does not actually set a lightmap resolution that will be used. This setting determines the padding between the UV shells when it gets repacked into a lightmap. Larger resolutions means that the UV shells can be packed more tightly since there is more resolution to work with.

Lightmap Resolution is the actual resolution you want to use for the baked lighting. This value will directly affect your light builds and bake quality.

I hope this helps.

Tim

So if I have the “generate lightmap UVs” unchecked, the Min Lightmap Resolution is irrelevant- is that correct?

Not correct. Lightmap resolution is always relevant, unless you’re using dynamic lighting since there is no need for baked lighting.

The build settings just allow you to generate and have a little bit of control for the target resolution and repack of the lightmap UV.

If you uncheck the generated lightmap option the editor will either use UV Channel 0 (texture UV) or use a pre-existing one for the lightmap bake.