Unity - The multiplatform game creation tools for everyone.
STP Viewer - Free STP Viewer - free software that lets you view 3D STEP files (.stp, .step file format).
Godot Engine - Feature-packed 2D and 3D open source game engine.
A360 VIEWER - Free online CAD Viewer
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
DXF View - A lightning-fast drawing viewer enables you to view DXF and DWG™ files on Mac