I had a simple level and at some point I desided to add a light to it. But after adding few spot lights - each time then when I rebuilding light it totaly breake meshes. Below are 2 screenshots
If I only move-resize any mesh - everything gets back to normal. But this behavior is kinda annoying.
I tried to restart editor but this does not helps. I removed all light expect default light source and skyLight but still this problem exists.
Why does this happens and how to solve this?
Just to give you a heads up I’ve edited the questions title since it’s not related to lighting. When you use the Build button in the tool bar it is also building the geometry (BSP) in the scene as well and not solely lighting.
In regards to what you’re seeing this is a known issue with BSP and using a lot of them in the scene. There are two similar issues that have been reported with UE-12157 and UE-15621.
Both of these issues are backlogged at the moment. There is no guaranteed time line for when these will be addressed.
I wouldn’t necessarily say that. I would just say that these kinds of issues are expected to some degree until Epic can get Geometry 2.0 worked on. The hope is that this will replace BSP/Geometry and not have as many issues. Unfortunately, it’ll probably be a while before this is worked on though.
Even though there is the graphical issues with the holes in the BSP, the face should still work right with collision so that the player cannot fall through, and if you were to convert your BSP’s to static meshes this would resolve the issue as well. although you would have to setup the collision.
As just an example of my workflow, when I’ve used BSP in previous projects I do something similar to your scene and just have a basic setup of my level scene. I then convert this to FBX and export this to a modeling software. Since I then have a basic FBX of my scene/level layout I can use this for scaling and blocking so that I can mesh it out with assets. Typically this is so I can make modular floors and walls that would work like lego blocks for my scene when I go to reassemble in UE4.
That doesn’t set the collision. That’s just a preset for how objects that have collision setup already will work with this object.
You will need to set the collision up in the static mesh editor by going to the collision option in the menu bar and choosing the method that works best.
More than likely you’ll want to use Box collision a couple of times and place boxes around that will act as the collision for the mesh.
Have a look at this documentation for help setting these up:
