Gouge checking is available in the 3 Axis Cut mode only, not currently in 4 or 5 Axis.
It is used in two circumstances: when the tool has curvature larger than certain parts of the surface being cut and when there are adjacent surfaces that may be gouged.
None
No gouge checking will be performed.
Single Surface
SURFCAM checks the entire surface being cut against the curvature of the tool and compensates for any undercutting conditions.
Multi Surface
SURFCAM checks adjacent surfaces and makes adjustments that will avoid gouging them. Select Multi Surface to activate the Check Clearance parameter. You will be prompted to "Select surfaces to avoid." Click those surfaces and click Done to proceed.