I was wondering if it is more efficient to have one large mesh at a higher lightmap res, or split it up into multiple meshes and have each individual mesh at a lower lightmap res? Thanks.
To keep draw calls down it’s better to combined multiple meshes - such as large structure objects etc. But things such as props are best to be left on their own so can be edited - have custom collision and so on.
To test which light map resolution is best - combined a few bigger meshes together and crank it to 128 - 512 - 1080 in UE4. Personally 1080 is really really big so if can help it keep it below this.
To set up the grid properly to account for the resolution you’re targeting you will need to do the following: 1 divided by # of pixels you want.
128 is a good one to start
To set your modelling UV gird for this do the following:
1 / 128 = .0078125 will be the spacing for your grid lines.
more info below