Do you really have to re-build lightning everytime you make a change?

I find this kinda annoying. Is it any chance that it will be gone in the future?

You could just use dynamic lighting ^^ Then you wont have to rebuild anymore

Hi Frequia,

This is a necessity when using static or stationary lights. The reason being that the light information needs to be rebuilt and put into a texture called a lightmap. This lightmap stores light and shadow information so that it does not have to compile it at run-time. This is great for performance gains because this lightmap does not have to calculate shadow information at run-time.

If you want to avoid this you will need to make your light sources (directional, point light, and spotlight) movable rather than static or stationary. This can cause an FPS hit depending on the number of shadows being calculated for your scene.

If you have any other questions feel free to ask!


Fighter! You sir are too fast! :stuck_out_tongue:

You always beat me by a few moments! haha

So if I use movable lights, I dont need to re-build lightning anymore?

If you movable lights you will not need to rebuild lights any longer.

However, as stated before there is a performance hit for this depending on the number of meshes in the scene that are casting shadows and the complexity of the mesh.

You can find a little bit of information about movable lights here.

Thanks for the link, will have a read. And thanks for the help :slight_smile:

And you don’t actually have to rebuild lights, it’s probably best to do some work and once you’ve done a more significant amount of work then do a build on Preview quality to see what it looks like. So you only do it from time to time, and once you’re done creating the level you do a build at Production quality.

I know this is an old thread, but I’d like to ask about the current situation with this…

  1. If the _BuildData is missing on the machine (say that e.g. it is not under version control), and I package a game, what will happen? Is the packaging process going to rebuild the lighting, or will those static and stationary lights have no impact on the baked lighting information?
  2. And what if there is the _BuildData file for the level, but it is old and not recalculated (say the case, when it would inform you in the top left corner about having to recalculate lighting, but you did not do that before packaging).
  3. And finally, what if the _BuildData is calculated and is up to date, but only built with Preview quality. Will a shipping package only contain Preview quality shadows baked in?


If you package your game the lighting will be in whatever state it is currently in, it doesn’t do anything to the lighting when it packages the game. So if it’s got that message about the lighting needing to be recalculated then it’ll have the message in the packaged game too.