Probably you’ve solved this by now, but if not I’ve written about unmapped texels (and why they are so important) on my blog http://niberspace.com/blog/speed-up-ue4-lightmap-build-times/
Probably you’ve solved this by now, but if not I’ve written about unmapped texels (and why they are so important) on my blog http://niberspace.com/blog/speed-up-ue4-lightmap-build-times/