All I’ve added to my level is a single cube. The shadow created looks nothing like a cube. Why and how can I fix this?
either rebuild the lighting on high/production quality settings (if you didnt do that already)
If you did and it turns out like this you might want to increase the lightmap of the floor mesh.
What are the performance changes in doing this? I set the lightmap for the floor to 2048 and it fixed the issue but I noticed it took far longer to rebuilding the lighting.
well, a 64x64 pixel lightmap only takes up a few kb, a 2048/2048 takes up several 10’s of mb’s. (though they are grayscaled so cant really give an accurate estimate) the reason it takes longer to rebuild the lighting is because the calculations need to be more accurate as well as more detailed.
You can reduce rebuild time of the lighting by setting the lighting rebuild quality lower. most of the time just using the preview quality is more than enough untill you are doing final rebuilds of lighting. (and saves you a lot of time!)
that said, most times 128, 256, 512 is more than enough unless a mesh is really huge.