Subsequently, a combination of features and power led to the rise of OpenGL, which became the most popular professional 3D API of the mid to late 1990s.
Although PHIGS ultimately expanded to contain advanced functions (including the more accurate Phong lighting model and Data Mapping), other features considered standard by the mid-1990s were not supported (notably texture mapping), nor were many machines of the era physically capable of optimizing it to perform in real time.
Models were built up in a Centralized Structure Store (CSS), a database containing a "world" including both the drawing primitives and their attributes (color, line style, etc.).
However, OpenGL's "low-level" API allowed the programmer to make dramatic improvements in rendering performance by first examining the data on the CPU-side before trying to send it over the bus to the graphics engine.
Given the low performance systems of the era and the need for high-performance rendering, OpenGL was generally considered to be much more "powerful" for 3D programming.