I think the discipline is being split into two groups.
Technical documentation is increasingly being handled by CAD, using the same drawings and models used to design and fabricate the products.
Marketing images are all photography or 3D, or some combination of the two. Any illustrations are usually less technical, more info-graphic, and are produced by graphic designers.
Post-secondary education is all about specialization, and usually targeted to the realities of the job market. You'll have to decide if you're more suited to the technical CAD side, or the more visual Marketing side.
I think there's room in the job market for someone who's proficient in both areas, but your job title will probably be one or the other.