A processor-based method for anatomical shell editing, the method comprising: generating a first anatomical shell of a cardiac structure, wherein the first anatomical shell comprises a first surface that intersects a first plurality of mesh points, the first plurality of mesh points corresponding to a plurality of signals, wherein each of the plurality of signals includes at least one respective sensed electrical signal; selecting a test point (610A, 610B, 610C), wherein the first surface does not intersect the test point (610A, 610B, 610C), the test point (610A, 610B, 610C) having a position within a test neighborhood of a position of a first mesh point; performing a test associated with the test point (610A, 610B, 610C), comprising: determining a first value of a metric corresponding to a voltage magnitude at the first mesh point, wherein the first value of the metric is a magnitude of the at least one respective sensed electrical signal corresponding to the first mesh point; determining a second value of the metric corresponding to a voltage magnitude at the test point (610A, 610B, 610C); computing a gradient feature of the metric based on a difference between the first and second values divided by a distance between the first mesh point and the test point; and determining whether an absolute value of the gradient feature exceeds a gradient threshold; and generating a second anatomical shell, wherein the second anatomical shell comprises a second surface that intersects a second plurality of mesh points, wherein: if the absolute value of the gradient feature exceeds the gradient threshold, the second plurality of mesh points includes the test point (610A, 610B, 610C); and if the absolute value of the gradient feature does not exceed the gradient threshold, the second plurality of mesh points does not include the test point (610A, 610B, 610C); displaying the second anatomical shell on a display device. generating a first anatomical shell of a cardiac structure, wherein the first anatomical shell comprises a first surface that intersects a first plurality of mesh points, the first plurality of mesh points corresponding to a plurality of signals, wherein each of the plurality of signals includes at least one respective sensed electrical signal; selecting a test point (610A, 610B, 610C), wherein the first surface does not intersect the test point (610A, 610B, 610C), the test point (610A, 610B, 610C) having a position within a test neighborhood of a position of a first mesh point; performing a test associated with the test point (610A, 610B, 610C), comprising: determining a first value of a metric corresponding to a voltage magnitude at the first mesh point, wherein the first value of the metric is a magnitude of the at least one respective sensed electrical signal corresponding to the first mesh point; determining a second value of the metric corresponding to a voltage magnitude at the test point (610A, 610B, 610C); computing a gradient feature of the metric based on a difference between the first and second values divided by a distance between the first mesh point and the test point; and determining whether an absolute value of the gradient feature exceeds a gradient threshold; and determining a first value of a metric corresponding to a voltage magnitude at the first mesh point, wherein the first value of the metric is a magnitude of the at least one respective sensed electrical signal corresponding to the first mesh point; determining a second value of the metric corresponding to a voltage magnitude at the test point (610A, 610B, 610C); computing a gradient feature of the metric based on a difference between the first and second values divided by a distance between the first mesh point and the test point; and determining whether an absolute value of the gradient feature exceeds a gradient threshold; and generating a second anatomical shell, wherein the second anatomical shell comprises a second surface that intersects a second plurality of mesh points, wherein: if the absolute value of the gradient feature exceeds the gradient threshold, the second plurality of mesh points includes the test point (610A, 610B, 610C); and if the absolute value of the gradient feature does not exceed the gradient threshold, the second plurality of mesh points does not include the test point (610A, 610B, 610C); if the absolute value of the gradient feature exceeds the gradient threshold, the second plurality of mesh points includes the test point (610A, 610B, 610C); and if the absolute value of the gradient feature does not exceed the gradient threshold, the second plurality of mesh points does not include the test point (610A, 610B, 610C); displaying the second anatomical shell on a display device.