Undo operations is something we will look into in the future, but it's not straightforward to implement as the voxelized objects, especially large ones, tend to use a lot of memory, so storing every previous version of them is not an option.
Right now the easiest way to make checkpoints is to save the voxel project whenever you're about to do something you're not sure about ('ctrl+s' is for save, 'ctrl+shift+s' for save as, also file -> save project), and then open the project to get back to the previous version.
We don't yet have a suggested workflow for dealing with dicom data, as the different datasets seem to need different filters applied to them. Some general guidelines would be:
- Remove small noise objects with 'remove small objects', min volume for example 10000.
- Remove some larger unwanted areas manually by selecting and removing them:
- open the selection manipulation toolbar
- (optionally) press '5' when in voxel editor to see your selections on the objects
shift-drag to select voxel object parts you wish to remove
- adjust selection size with sliders in the selection manipulation toolbar
- press remove in the selection manipulation toolbar to remove the selected area
- press esc to cancel the selection
- Use the gaussian filter to smoothen the object's edges and remove some noise
- Use a combination of 'remove noise' and 'close holes'
- don't use too large a kernel size as it may kill relevant parts of the model
- If your model permits it, use 'fill closed' to make the print easier on the printer
Following these steps gives a printable (with support) result on the Pied-cheville (feet) sample DICOM dataset from Osirix datasets.