Detailed three dimensional models are nowadays frequently used in cross-cut
ting (bucking) tree stems into logs and in breakdown processes of logs into
boards and flitches. Such models require increasingly sophisticated optimi
zation models to assist planners (or automated decision support systems) in
decision making. In this paper we develop two techniques that are linked t
o each other. The first is concerned with establishing high quality analyti
c approximations of full trees that are needed in full stem bucking applica
tions. One important aspect is that inaccuracies due to measurement error c
an be reduced. The second is a transformation technique that makes it possi
ble to apply curve sawing on logs in a standard straight sawing system. Num
erical results based on real data are presented that support the usefulness
of the techniques.