I am curious to know how the figures in popular introductory physics/Engineering textbooks are made. As examples of what I mean, see the posted figures and my comments, all from various editions of the Physics book by Serway and Jewett book (I think).
Look at all of these color gradients throughout the metals, and the imitations of lighting on the spheres. Notice the relatively realistic nature of the force scale and pullies.
Notice here that we have proper, LaTeX-like font on the mathematical symbols.
Wow. So many complex shapes, good water drawings, and the ability to annotate the drawing freely.
Lastly, we see more extremely complicated, realistic objects, like the ship and the mountain. But this isn't just pictures, it's clear that the software used has a very precise coordinate system in it, as evidenced by the kinematics drawings overlaid.
I am aware of other posts on Physics SE recommending drawing softwares such as PowerPoint, TiKZ, aymptote, mathematica, etc. But I highly doubt these figures were produced in any of these. My suspicion is that the publishers have some specialized software for this task. So what is that software? Does anyone know? The Physics SE did not have the answer...
It is important to realize the stipulation that one must be able to type properly formatted mathematics (using some manifestation LaTeX) into the figures. I say this because I intend to use such figures in a book, and the fonts must match.