The field of aerospace engineering focuses on giving mankind wings, whether those wings soar through the air or through outer space. In this industry, a great deal of time is spent testing theoretical designs for airplanes and spacecraft without ever building a single thing. These things are tested by creating 3D animated models that interact with a physic engine to test proposed designs and make adjustments prior to prototype fabrication.
In industrial engineering, trained engineers create systems and machines that drive manufacturing and industry such as vehicle production, parts fabrication, plastic molding, and numerous other applications. While similar to mechanical animation, industrial engineering focuses more on the methods than the end result. Using engineering design programs such as AutoCAD, engineers can create 3D models of production line equipment and systems, as well as parts that may need to be machined. These models can provide working demonstrations of how industrial systems and equipment would work in an optimal environment.
Astronomy involves observation of the stars and other celestial bodies in an effort to understand the universe we live in, and its behavior. But when stars, nebulae, planets, galaxies, black holes, and supernovae and other phenomena are so far away that we can barely observe their behavior by telescope and could never hope to reach them in a hundred lifetimes, we fall back on 3D models and simulations to try to predict and understand their behavior by recreating them in digital facsimile. In many cases this is the closest we can come to actually observing certain things, such as the event horizon of a black hole. Because we lack the tools to gather certain key data these 3D animated simulations are often only partially accurate, but they still provide a base to discover new information about the universe we live in.
This particular science is actually a branch of astronomy, and involves not just understanding the objects in our universe and their behavior, but understanding the forces that drive them and create the physical laws of our world. This can involve determining the nature of time as the fourth dimension, understanding the effects of the gravitational pull of nearby bodies on the formation of a new star, studying the effects of planetary magnetism on atmospheric development, and numerous other things - things that take place over thousands, millions, and billions of years. So how can we possibly study them with a lifespan of less than 100 years? By using what data we can gather in - you guessed it - 3D models and simulations. These simulations can create virtual physics engines that mimic the behavior of universal forces on objects created in the 3D environment, and provide valuable information on everything from the universe's formation to the concept of entropy.
Similar to aerospace engineering, the field of astronautics focuses on flight - spaceflight in particular. Spaceflight is extremely expensive, time-consuming, and dangerous, and is only attempted once proposed spacecraft designs and the physics of the launch parameters have been thoroughly tested. Initial tests often take place on a virtual stage, rather than a physical one, to eliminate any potential problems before they see the light of day and test proposed designs and actions against the laws of astrophysics.
When you're working with something too small to see, in environments that often require highly expensive equipment, precise conditions, and sensitive calibrations to gather minute amounts of data, it's often more efficient and practical to work, instead, with 3D simulations. These 3D simulations can take known data about atoms and other particles, and run scenarios that estimate the behavior of these particles in particular situations as defined by the program. The animations can be used to gather theoretical data to further support hypotheses and guide scientists in determining the best course of action in pursuing further real-world testing.
Similar to nuclear physics, chemistry and chemical engineering often involves working with molecular compounds that are difficult to handle in experimental situations, whether because of their rarity, their volatility, or the danger involved. When dealing with new chemical compounds and formulations, chemists can use 3d animation and simulation programs to analyze how molecules should theoretically interact with each other when combined in particular ways, and the behavior of the compound produced, prior to actually mixing and producing those chemicals. This can identify potentially adverse reactions, or even unforeseen positive side effects. It can also help with troubleshooting problems when molecules don't combine in the expected fashion.