STEP

STEP (ISO 10303) is an international standard for CAD data exchange, preserving precise geometry via NURBS surfaces and solid modeling. Widely used in mechanical design and engineering, it retains parametric features and assembly structure, unlike mesh formats (STL/OBJ), enabling lossless transfer between CAD software.

STEP prioritizes engineering precision over real-time rendering, so browsers and game engines require conversion to mesh formats. A typical workflow: design in CAD, export STEP for archiving, then convert to STL/GLB for preview, printing, or Web display. The extensions .stp and .step are equivalent.