Really bright effect

[CarnivorousJelly]

HPL2 can be pretty messed up sometimes and it's hard to fix everything. Like Mudbill said, it's probably an issue with the shaders, but there are some workarounds you can use that don't involve having to create an IFC

Definitely try connecting the billboards to a dimmer light source (I find 12-25% as bright as your light source works well). You can make the radius of the new source small (0.125, for example) and stick it somewhere that the player won't encounter it. If that doesn't achieve what you want, alpha's a good next step. Otherwise...

For the lamps, you have a couple options:
- set them to 'off' and use just the pointlight for lighting source from it
- connect the pointlights to the light entities set ALL the values on the pointlight to 0.125 or lower (this will cause it to behave as a dimmer version of the light, effectively extending its casting radius but also causing it to fade out more gradually)
- open the lamps in the model editor and delete/alter the attached light; make sure you save this as a new entity

For the windows (this could go for lamps too):
1. open the material in the materials editor and delete the illumination layer
2. save it under a new name
3. apply it to the model using this tutorial
4. save the model under a NEW NAME
5. use this model instead; be sure to include it in your CS folder when you release it or people will get some rather weird effects (like missing walls)

Let me know which one worked best for you!