Can we get a mathematical equation for a 3D geometry prepared in software from the software itself?

For eg, for my project I wish to seek the the mathematical equation of the fuel tank of the 4 wheeler, may it be any vehicle. Now given it would be tough to find the model as such on the web but if I'm able to recreate the design on the software is it possible that the software also gives me the mathematical equation of the same.

1 Answer

Export the part into a text format (Like .DXF) you will find the points and the type of entity (like Line, Circle, spline, etc) that describe your part.
You can try different basic shapes then try a 3D model and develop the method