3D applications have different approaches to processing matters; the way in which their functions handle things are distinguished. The algorithms in which they calculate certain processes are different formulas. In this respect they resemble people all of whom have different talents (or not) and different things at which they suck (pardon my French). The image below is an example of the different way of handling of matters.
The fillet of the object at the top is irregular while the bottom one is smooth. It is an angled joint of two pipes of a different diameter - one of the constructions that a number of 3D programs do not handle well. The fillet actually looks like a real life weld of welder who was not too skilled. Also the fillet command disrupted the surface of the slanted pipe, assuming the bigger pipe had a thicker wall than the slanted pipe. The application producing the poor filleting does an excellent job at other types of modeling, because it does not have to take into account for what welders encounter in real life, like amperage setting, measures of gas supply, navigating difficult to access tight spots, using different types of welding machines and electrodes. 3D renderings do not have such options and limitations because they are creating animations, are of the virtual world. It is probably why many 3D artists use various applications to achieve whatever they want to achieve, presuming that the export files are compatible to continue to work in order to create a visually correct appearance. This property does not exclusively apply to filleting; 3D applications are capable of creating complex constructions that can only be built in real life with 3D printers, simply because traditional CNC machines are unable to reach and process complex areas.
3D printers waste far less material than traditional subtractive machining, that has more production limitations and results in more waste of material. Bridging those gaps becomes less difficult as 3D printing continues to evolve into methods never seen before until relatively recently, like advanced 3D printing objects from a specialised liquid with innovative approach, that actually is capable to translate digital constructions into real life manufacturing of ultra complex parts without interference of materials and greater strength than CNC machines can achieve, without expensive industrial robots, admittedly at a lower pace at this point in time. But as we have witnessed over the past decades, such problems will one time be resolved, like progressing from digitally flawed 3D fillets to far more elevated production techniques. Not just in the industrial sector, but also in the advanced medical field in which is called Tomographic reconstruction, with which tiny parts of internal organs of the human body are built. All of this remarkable progress has taken place in roughly over thirty years.
