It didn't get sculpting until around ZB 1.5 or so.

It actually started out without any kind of 3D sculpting and was just a 2.5D 'pixol' painter where you could spray pixels around on a canvas with some depth and lighting to the 'pixols'. ZBrush is godly in terms of performance but I think it's because it was made by image processing experts with assembly expertise (it's also likely due to the sheer amount of assembly code that they've been almost 20 years late in porting to 64-bit). (Please don't post answers like 'just use opengl' or 'learn math', this seems to be the reaction everywhere I post this question but these replies are off topic) I'm already reading Michael Abrash's Graphics Programming Black Book but it's not really addressing these matters or I just haven't reached that point yet. I'd appreciate any info on any question and a recommendation for a book that covers any of these topics. How much of a hassle would it be to display just a single pixel without any preexisting tools and what magic gives ZBrush such performance. How are graphics libraries made and how does one access the framebuffer without the use of opengl. This made me want to learn graphics on a lower level but I have no clue where to start. For the moment I just assumed ZBrush was heavily hardware accelerated, imagine my surprise when I found out it's not and furthermore it uses neither opengl or direct3d.

Sure enough I got it done, I couldn't match ZBrush's performance of course seeing as how a brigade of well payed professionals outmatch a hobbyist. After a while of 3d modelling and enjoying ZBrush's impeccable performance and numerous features I thought it would be great OpenGL practice for me to create something similar, just a small sculpting tool.

Z brush