There are four different modes in the collision management
"check and retract if collision"
When TopSolid detects a collision it removes the part of the tool path in collision and apply a retract along the tool axis.
"auto tilting (main direction), retract if collision"
When TopSolid detects a collision it limits the angle variation of the tilting in the main direction to avoid collision. If there are no solution TopSolid will remove the the tool path in collision and apply a retract along the tool axis.If there are no solution TopSolid delete the part of the tool path in collision and retract along the tool axis.
"auto tilting in any direction (heavy computing), retract if collision"
When TopSolid detects a collision it tries to orient the tool following any direction to avoid it.When TopSolid detects a collision it removes the part of the tool path in collision and apply a retract along the tool axis.
"No check"
TopSolid doesn't check the surfaces. It doesn't check the collisions with the body of the tool.