With the Advanced User Settings the optimisation parameters can be influenced even further than the options Strut Density and Shape Quality. Furthermore, a few unsupported options are available using the Advanced User Settings like Restart, Usage of a Startspaceand preventing an Intersection during the optimisation.
Restart, Usage of a Start Space & Influencing the Strut Density
To influence the Strut Density even further, changes of the number of iterations, stress goal percentage and number of resolution levels can be made. These settings overwrite the selection of the Strut Densityand the Shape Quality as they are only default settings for the ones described here. The table gives an overview of the default settings:
Input Commands | Explanation |
|---|---|
UpSampleConfig fOptimizer_switchAddRemove=58 | Starting with iteration 58, elements are either added or removed and only every second iteration is saved. This is important for the iterations near to the end of the optimisation. |
iteration .level_3=20 .level_2=20 .level_1=20 .level_0=4 | Specify how many iterations are calculated at which resolution level. Note that convergence should be achieved at each level. Default settings medium: 20, 20, 20, 4 Default settings sparse: 16, 40, 4, 4 Default settings dense: 10, 10, 40, 4 |
Optimizer_stressPercentGoal .level_3=30 .level_2=40 .level_1=90 .level_0=100 | The percentage at which the target stress is reached is set. Default settings medium: 30, 40, 90, 100 Default settings sparse: 60, 90, 95, 100 Default settings dense: 10, 25, 50, 100 |
The software uses four resolution levels from coarse to fine (level 3: coarse - level 0: fine). More or less resolution levels can be added or removed. The number behind the level indicates the number of iterations calculated on this resolution level. Moreover, the stressPercentGoal for each resolution level can be changed. More information about the stresses and resolution here.
To set up these additional parameters, the Input Commands (left side of the table) need to be added to the optimisation model in the Advanced User Settings. You should always make sure to give the optimisation enough iterations on one level to give the optimisation the chance to reach a convergence in each level.
Restart (Start Space)
With the Advanced User Settings a Restart is possible. A Start Space needs to be chosen with which the optimisation will re/start.
Therefore, an already optimised STL-file is needed as a Start Space. Therefore, the unit of the exported STL-file needs to be in the same unit as the rest of the model. In most cases the Strut Density and Shape Quality settings must be changed as well using the Advanced User Settings. For a restart the same resolution level and number of to be completed iterations have to be filled in.
This way a two-stage optimisation is also possible. An already optimised geometry can be changed (adding a strut, removing a strut) and the optimisation can be started anew. For a two-stage optimisation the resolution level and number of iterations must be chosen wisely and will need some fine tuning.