What is the exact problem?
That textures fade out where the model disappears is normal and the way it has to be ( a higher level of ambient light might help here ).
The only other thing is to make the whole mesh not responding to light with setting it to fullbright.
For lightmap: Try Blendmode 5
Multiply ( mode 2 ) can only darken
Add ( mode 3 ) can only brighten up
MultiplyX2 ( mode 5 ) can both, with 128,128,128 as neutral
That textures fade out where the model disappears is normal and the way it has to be ( a higher level of ambient light might help here ).
The only other thing is to make the whole mesh not responding to light with setting it to fullbright.
For lightmap: Try Blendmode 5
Multiply ( mode 2 ) can only darken
Add ( mode 3 ) can only brighten up
MultiplyX2 ( mode 5 ) can both, with 128,128,128 as neutral