I was showing someone how the bump (Displacement) worked in TG2 and discovered a shadow that popped up when using a negative value. However it does not start until the 1 crosses the decimal point on the left. Example: Default value displacement is 0.01, make it negative -0.01 and is OK. It is OK at -.1 also, but make it -1 and the problem starts.
The first image is Default Displacement 0.01.
The second is with -1 Displacement.