Emissive lighting for Lightmass is REAAAALLY slow...?
polycounter lvl 13
I've got a number of assets I'm working on that use emissives either for minor detailing or as fully diegetic light fixtures.
I've been reading the lightmass documentation and it mentions that using emissives for lightmass should be about as expensive as a point light, but when I toggle even just ONE mesh with emissive to use it for lightmass, lighting build times jump by a factor of probably 20 or more. I'm using the October build of UDK.
EDIT: A production quality lightmass build with only three meshes (64px lightmap each) on the default midday map, WITH a LightmassImportanceVolume, took FORTY MINUTES.
I've been reading the lightmass documentation and it mentions that using emissives for lightmass should be about as expensive as a point light, but when I toggle even just ONE mesh with emissive to use it for lightmass, lighting build times jump by a factor of probably 20 or more. I'm using the October build of UDK.
EDIT: A production quality lightmass build with only three meshes (64px lightmap each) on the default midday map, WITH a LightmassImportanceVolume, took FORTY MINUTES.
Replies
Yes casting shadows.
Where is the explicit control of mesh emissive radius? I'm not finding it under the mesh properties in the Lightmass section where mesh emissive is enabled for lightmass...
The doc says it will automatically disable emissive lighting on a static mesh with more then 5k tris.
Most of them are under 300 polys, some of them (double checked, ONE) are a few thousand though. None of them have triggered those warnings.
The art design for these structures and environments has lights built into a lot of elements as task and diegetic lighting. I'll look into breaking off just the emissive parts to see if that improves lightmass times. Going to be a royal pain in the butt, though...
Ah OK, thought you meant something else! Thanks...
bit easier to deal with than using the emmsive map for lighting and having to fuck with the emssive boost.