Please help me the shadow is not right, lightmap resolution to 1024. im not sure because the shadow from the wall it looks correct but the shadow from the ground is wrong.
If the ground is BSP then you need to select that surface and reduce the number for the lightmap resolution. If it’s a static mesh, then make sure that the lightmap resolution setting your changing is for the actual lightmap and not the lightmap UV’s generation settings. You can also select the static mesh in the level and then use the lightmap resolution override. If it’s still too low resolution then you either need to improve your lightmap UV’s so that they utilize the UV space better or you need to split up the mesh so that it can use more lightmaps for the area.
It’s a very large floor, even for a 1024x1024 lightmap resolution. Usually my terrain consist of a single plane to make sure I use the most of my uv space!
The reason why the shadow from the perimeter walls look good is that the direction of the shadow is parallel with the pixels in the lightmap. The diagonal shadows look bad because they’re not so the engine needs the draw a diagonal across what it seems to be far to few pixels. Count 1024 pixels from one side to another and you’ll see how much that is. Also, if you’re using a cube static mesh actor that’s a very poorly optimized way of handling a floor surface.
It is probably for testing purpose tho, it’s the default scene.