Measurement on segmented volume

Hello, Sir/Madam
I tried linear measurement on segmented volumes with the smoothing factor. I applied varying levels of smoothing factors to obtain a realistic shape. However, the sizes of the volumes get altered tremendously with each level of smoothing factor. Is there any way (besides the smoothing factor) to generate a realistic image/shape

without altering the volume? or how do I adjust the smoothing factor to obtain the same? Thank you.