Light and texture in Quark.

#1 See if it helps by applying omni-light on each affected areas.

#2 I think its due to the light from your light source on the other side. I call them light leaks, and let me tell you I havnt found a way to get rid of them without either adding more lights or removing the ones that are causing the problem.

#3 I already have omni light, I tried to change the fallout2 value to 1000 (500 for the picture) and it is much better now.

Anyone have precise description of what fallout1 and fallout2 values mean ? I did not found any, just played with values till it look right and I don't like this approach :(

#4 Try this link. Desmond explains how the light works in Quark.

holodeck.st.usm.edu/vrcomputing/vrc_t/tutorials/editing/

#5 There are two things you can do to fix this:

1 - reduce your lighting scale (in the world spawn entity).
2 try to align your brush edges with a coord that is a multiple of the lighting scale (for default lighting scale of 32, valid coords are ... -64, -32, 0, 32, 64, ...).