Re: Smooth models
Create CAD model
Convert CAD model into a mesh defined by thousands of triangles (*.STL)
Take STL into 'slicing' software, that has had machine-specific variables (material, print temp, bed temp, bed size etc) loaded into it:
- analyse overhangs and create support structures if need, either 'break away' or using a second extruding head
- slice the mesh and added structures into hundreds of 2D slices
- create G Code that controls the movement of the print axes, lots of factors here including print temperature and speed.
Put G-code into a software 'print simulator', to make sure the slicing software hasn't got confused.
Load G Code onto the 3D printer.
Spot an issue, fine tune some of the above variables, repeat steps as required.
Cross fingers, go to pub for a couple of hours.
There is certainly room for improvement. There is no real reason why the intermediary STL format is required, when my instincts tell me the 2D slices or the actual G-code could be generated directly from the original 3D CAD model, with greater respect for the 'design intent'. The GCode format itself isn't perfect, either.
Really, systems are getting smarter. There is no reason a depth aware system akin to MS Kinect couldn't be used to provide real-time feed-back to the control system to compensate for any physical variation in the print process (belt tightness, ambiant temperature, variation in material composition). I'm not sure that the current Gcode system is suitable for this scenario.
AutoDesk's products, like those from their competitors, already have simulation plugins and the like... there is no technical reason one should have to leave one's familiar CAD interface in order to print the object.