topography optimization - how to make design more discrete

Hello,

I perform topography optimization in hypermesh/optistruct. My model is mostly red. What should I do to reduce red region? In some manual I saw remark that more discrete (less red) designs are obtained with smaller 'beadfrac option'. I don't know where to change 'beadfrac option' parameter.

My settings:

Minimum width=1.0

draw angle=60

draw height=1.1

buffer zone=checked

boundary skip: loads&spc

response: beadfrac

objective: min beadfrac

manual: 'Concept design with topology and topography optimization'