Ideal Lightmap Resolutions

[Teriander]

I understand that the resolution for lightmap (default 64) is dependent on the object. But what is the best way to know the ideal resolution for each object? For example, if I have a square floor thats about 20' x 20' should this have a lightmap resolution of 1024 or higher? Then if I have a small object such as a desk on that floor, should it have a smaller resolution of like 128 or lower? Or is it entirely depended on the size of my lightmap UV layout and how it looks during Lightmap build?

Basically is there a rule-of-thumb that you should never go higher than 1024 or something? Or a workflow of - start low, test, increase until it looks good enough?

Thanks

[darthviper107]

Flat planar objects can actually have a pretty low lightmap resolution since they are super efficient at using the UV space.

But there's no set rules to go by, one surface could have a really low resolution, but another could require a higher resolution because there's more things casting shadows on it.

Best rule of thumb is to use as low as possible.

[Teriander]

Thanks Darth Viper, I just saw a video that did a good job of explaining the resolutions and your answer also sums up my question.

Thanks for answering!

[Sam Deiter]

I understand that the resolution for lightmap (default 64) is dependent on the object. But what is the best way to know the ideal resolution for each object? For example, if I have a square floor thats about 20' x 20' should this have a lightmap resolution of 1024 or higher? Then if I have a small object such as a desk on that floor, should it have a smaller resolution of like 128 or lower? Or is it entirely depended on the size of my lightmap UV layout and how it looks during Lightmap build?

Basically is there a rule-of-thumb that you should never go higher than 1024 or something? Or a workflow of - start low, test, increase until it looks good enough?

Thanks

A rule that I always follow is to start out as small as possible and then move up in size as needed. There is no point in making a light map 128 or 256 when a 64 or 32 will do just fine.

[Teriander]

Sam,

Yes, that seems like the ideal solution. I've also learned how to properly space my LightMap UVs to keep them from bleeding into each other, this helps a lot. At first I was increasing the resolution to hide bleeds, that was just masking my problem instead of solving it. Today has been an unreal learning experience!