To extrude a 3D model (including node-based workflows) without ZBrush, use software like Blender, Maya, or Cinema 4D—all support extrusion for faces, edges, or vertices.
Select the area to extend, activate the extrusion tool (e.g., press "E" in Blender or choose "Extrude" in Maya’s menu), then adjust depth or direction via mouse movement or numerical inputs. For node-based modeling (like Blender’s Geometry Nodes), use the "Extrude Mesh" node to proceduralize extrusion by connecting it to your mesh data.
If you’re new, start with free Blender: open a default cube, select a face, press "E," and move the mouse to see how the shape changes—practice with simple objects first to build confidence.